Geodetic works are one of the most important components of any construction. They are the process of measuring, designing and calculating in the form of drawings. Thanks to the work on geodesy, it is possible to determine the most accurate and expedient placement of construction objects in accordance with the requirements of legal norms, the violation of which is fraught with serious consequences.
The definition of the science of geodesy refers to the study of the earth's crust, its structure, surface, as well as any changes associated with it. Geodesy has a close relationship with such sciences as mathematics and physics. It is geodesy that helps specialists transfer the coordinate system to the surface and model in real scale, create geodetic networks, and determine the necessary points.
It is customary to distinguish the following stages of work:
- preparatory;
- field;
- cameral.
The first stage is designed to study the available documentation, which is directly related to the territory. Here, in the future, the implementation of the intended goals and the construction of carefully designed facilities are expected. Timing preparation will depend on the size of the facility and the locality in which the study is being conducted.
The engineering and geodetic process falls on the field stage. During this period, all work is associated with direct binding, removal of rocks. Based on the measurements, a topographic map is compiled on a scale. The scale of the map is determined by the tasks. So, if the task is to study the area as accurately as possible and give the most complete description of the rock on which construction is planned, then a three-dimensional topographic map is compiled.
Graphs can be drawn up in the form of drawings, or they can be recorded in a digital medium.
Geodesy of the land plot ends with a cameral stage. The completion of this stage is the preparation of the most detailed report on the actions taken and the results obtained. The document contains catalogs of coordinates and heights, fixing the location of a high-altitude geodetic network or several networks schematically. This stage is considered final, but no less important, since it is at the end that a summary of the information received and decision-making are carried out.
Types of geodesy
Geodetic works are divided into several types. Each of them is responsible for a certain category of measurements, surveys.
Types of geodetic works:
- Topography is a description earth's surface. This type engaged in surveys of various scales, updating topographic maps and plans, surveying engineering communications, underground and surface structures. When shooting, a mandatory requirement is the use of established scales and their observance. It is necessary to carry out such work during the construction of high-rise buildings, if necessary, redevelopment, reconstruction of large-scale engineering and technical structures, and the implementation of landscaping work in parts of the city. The most accurate scale is used for measurements in a populated area, when planning the construction of a highway, transport interchanges, large companies industrial production.
- Engineering or practical geodesy is a set of works consisting of studying and surveying the relief in the territory, area where construction is planned.
- Hydrography is a type of work that deals with the description of water space.
- Marking work is a kind of activity of surveyors, which involves the placement of specialized signs for linking to the state geodetic network. These signs are placed and preserved until the end of the entire construction. This allows you to control the quality construction works. When carrying out marking work, drawings are built that are tied to the real area. After drawing up the drawings, the removal to nature takes place. For this key points fixed directly on the ground. The results of the work carried out are sent to the design surveyors with all the schedules and drawings.
- Executive surveys are works that are carried out until the end of construction. With the help of filming, you can control the order of building construction and compare it with the planned drawings. Increased attention is directed to that part of the object, which is the carrier and it is the main focus of the entire structure. In other words, this part of the building or structure fully ensures the stability of the entire structure. All possible deviations that occur during the period of work are compared with the established rules and norms of GOST. According to the results of the shooting, acts of acceptance and transfer are drawn up.
- Control over the deformation of structures - this kind of measures is carried out not only at the stages of construction, but also after its completion. Monitoring is carried out during the laying of the foundation, and so on every five floors. At the end of construction, control check and then operational. The shrinkage of the building, the flexibility of structures and individual parts of the entire monolith are subjected to control. In addition, surveyors conduct research on how the erected building affects the nearby buildings and structures.
- Shooting underground networks - there are many factors that can affect the shrinkage of an erected building. It is impossible to predict them all. In this regard, it is necessary to constantly measure the condition of underground networks. This type of control is carried out with the help of shooting, which fixes the position of all communication networks, drainage, wells and sewers. The result of such a study is the preparation of a situational plan.
In addition to the above types of work, mine surveying will stand out, dealing with measurements during the construction of tunnels, underground roads, structures in the mining industry. Also, geodesy is engaged in cadastral work, which citizens who have a plot in land use have to face.
It is very important to remember that when ordering work, you need to take into account the level of skill and experience of the surveyor. If the company is not well-known or has negative reviews, you should not contact this organization, as there is a high probability that the work will be carried out poorly. As a confirmation of professionalism, you can ask a surveyor or an employee of the geodetic service to show a document confirming his qualifications. Geodetic work should be carried out by a qualified specialist.
Geodetic measurements, topographic survey of sites are faced not only construction companies with large objects, but also individuals. Anyone who acquires land for the purpose of individual construction must issue a cadastral passport for the object.
To systematize all real estate in Russia, a special cadastral registration is carried out. It contains information about all objects, their location, size, and purpose. Each object is assigned a number.
In order to obtain a cadastral passport for an object, it is necessary to follow the sequence of actions. First of all, work on the survey of the site should be carried out. A citizen needs to apply to an organization that has a license to carry out land cadastral work.
The cost of performing the work will depend on the method and the region in which the research is conducted.
The total volume of cadastral work carried out by surveyors includes:
- Cadastral survey of a piece of land.
- Request for information in the cadastral registration. Information is provided in the form of a territory plan.
- The surveyor notifies the neighbors in the area about the meeting to agree on the boundaries of the location of the land.
- A boundary plan is formed on paper and electronic media. It is necessary to put the object on the cadastral register and obtain a passport.
After carrying out all the necessary geodetic work, the applicant may apply for the production of a cadastral passport. Until January 1, 2013, only BTI was engaged in it. Now the registration is handled by the Cadastral Chamber, which is part of Rosreestr.
There are two ways to get a passport issued by the cadastral chamber: at the MFC or ordered on the Rosreestr website. Sending documents by any of the above methods will be legally binding.
The term for the production of a cadastral passport through the MFC is 5 working days, when applying via the Internet, the period will be 2 working days.
Geodetic and cadastral works are closely interconnected. They cannot exist separately. Without carrying out geodetic work, it is impossible to obtain a cadastral passport. The implementation of this kind of research of territories makes it possible to determine which category the land belongs to and whether the legislation in the field of land use is violated.
If a cadastral passport has already been issued for an object and a cadastral number has been assigned to it, anyone can get information on it. It is freely available. To obtain it, you must write an application indicating the number or find the object on the official website of Rosreestr.
If the object is only put on the cadastral register, then this can be done only after a land survey, which is ordered personally by the owner of the property.
The decision on cadastral registration is necessary both for the owner himself and for the state as a whole. The first is the payment of property taxes. This allows you to streamline taxes and fees. But to perform such actions, you need to have accurate information about the objects. In this regard, the state obliged citizens to draw up cadastral documents. Without them, no transaction is possible.
By assigning a number and receiving a passport in hand, the owner acquires full rights, and the state acquires the full information necessary for calculating taxes.
A passport issued by the Cadastral Chamber is required in the following cases:
- when making transactions with real estate, here it is included as a sale, donation, testament;
- when redevelopment of the apartment, changing the boundaries of the site;
- at litigation;
- according to the requirements of banks.
A cadastral passport will always be required in cases where it is necessary to confirm that an object is included in the cadastre.
A cadastral passport is obtained for the following types of object:
- Plots of land.
- Houses, buildings, unfinished buildings.
- Premises.
The cadastral passport does not have an expiration date, it will be valid until the data entered in the cadastre is changed. It is required to issue a new paper when a redevelopment of the premises has been made or the boundaries of a plot of land have been changed.
The cadastral document received before January 01, 2013 has its own validity period. For residential premises, the document was valid for one year, after which it was necessary to apply again to the cadastral chamber for an extension of the term, for all other structures - 5 years. But after the transfer of authority to the BTI to Rosreestr, such actions are no longer performed.
When working on sites, surveyors use specialized tools. With their help, accurate calculations are made, measurements are made in compliance with the required scale.
These tools include:
- A level is a device used to measure the points of an object during construction.
- A total station is a tool for measuring heights and angles of points in space. Often an electronic device is used that stores information and then sends it to a computer.
- Theodolite is a device for measuring angles. It can be optical and electronic. In order to securely install it, you must have a special tripod.
Geodetic work is a precision design method. Their task is to make the structure as correct as possible in nature. All measurements are entered into special geodetic documentation, which is carried out from the moment construction begins and until the stage of commissioning the facility.
4 How is the roll of a building determined by measuring horizontal angles?
1 Organization of geodetic works in construction
Types and composition of geodetic works.
Geodetic works in construction are carried out in a certain volume and with a specified accuracy, which ensure that the geometric parameters are consistent with the placement and construction of construction objects project documentation requirements building codes and rules. The works are divided into the following main types: surveying, tracing, marking, and also executive shooting, monitoring the deformation of construction objects. Surveying and tracing works precede construction design and are carried out during the period engineering surveys.
Layout work is carried out directly during the construction period and is intended for the removal of axes and points of buildings and structures from the project to the area. Executive surveys are carried out during the construction process and at its completion in order to control the implementation and quality of construction and installation works, as well as to draw up a new plan for the built-up area. Observations of deformations of construction objects are carried out from the beginning of their construction to the end of construction and, if necessary, continue during the period of operation. The composition of geodetic works related to their implementation directly at the construction site includes:
creation of a geodetic marking base for construction, including the construction of a marking network of a construction site and the removal to nature of the main or main marking axes of buildings and structures, main and off-site linear structures, as well as for the installation of process equipment;
breakdown of on-site, except for main, linear structures or their parts, temporary buildings (structures);
creation of an internal staking network of buildings (structures) on the initial and installation horizons and a staking network for the installation of technological equipment, if this is provided for in the project for the production of geodetic works or in the project for the production of works, as well as the production of detailed layout works;
geodetic control of the accuracy of the geometric parameters of buildings (structures) and executive surveys of completed objects or their individual parts with the preparation of executive geodetic documentation;
geodetic measurements of deformations of foundations, structures of buildings (structures) and their parts, if it is provided for by the design documentation, established by the author's supervision or state supervision bodies.
Above geodetic works are a necessary part of the technology of construction and installation works and are carried out according to a single schedule, linked to the timing of the process construction industry and special works. The creation of a geodetic staking base for construction and geodetic measurements of deformations of buildings (structures) and their parts during the construction process are performed by the customer. The contractor's responsibility includes geodetic work during the construction process, geodetic control of the accuracy of the geometric parameters of buildings (structures) and executive surveys. For large and complex objects and buildings above 9 floors, projects for the production of geodetic works (PPGR) are developed in the manner established for the development of projects, production of works (PPR). PPGR can be developed both by the contractor and specialized design organizations (on the instructions of the customer).
Prior to the commencement of geodetic works on the construction site, the working drawings used in the layout work must be checked in terms of the mutual coordination of dimensions, coordinates and marks and allowed for production by the technical supervision of the customer. Geodetic work should be carried out with measuring instruments of the required accuracy. Geodetic instruments must be checked and adjusted in accordance with the established procedure, checked regularly before starting work.
Geodetic work begins to be carried out after the clearing of the territory provided for by the design documentation, its release from buildings to be demolished, and vertical layout.
Organization of service of geodetic works.
Geodetic support of design survey work and the construction of buildings and structures is carried out in the following order.
At the stage of design and survey work, geodetic services in the city are carried out by a department under the chief architect of the city.
Geodetic department performs the following works:
draws up a plan for the development of facilities and the location of underground utilities;
issues permits for topographic and geodetic work and engineering and geological surveys in the development area, and also conducts planning, accounting and acceptance of these works;
carries out registration, storage of topographic-geodesic and engineering-geological materials;
monitors the safety of geodesic signs;
allocates land plots, brings out the red lines of development in nature.
The provision of topographic and geodetic materials is carried out by the geodetic service at the engineering survey department of the design organization, as well as engineering and construction survey trusts, where the departments (topographic and geodetic, engineering geology, etc.) specialize in the types of work performed or in the complex of all survey work on types of construction.
At the construction stage, the maintenance of geodetic works is carried out by the geodetic service, headed by the chief surveyor, at large construction associations and central offices. This geodetic service manages and controls the work of geodetic services of construction organizations, develops regulatory documents for geodetic work, and organizes advanced training for surveyors.
The main task of the geodetic service in construction organizations is to carry out a set of works that ensure the exact correspondence of the position of the structures being erected, buildings, structures and technological equipment to the project. The geodetic service carries out:
acceptance from the customer of topographic and geodetic documentation for construction objects fixed at the construction site of support networks, main axes of buildings, utilities and construction grid;
acceptance of general plans, construction general plans, working and layout drawings of objects with verification of geometric dimensions, coordinates and elevations;
coordination of WEP and PPGR for objects for which these drawings are made by design organizations;
if necessary, the development of a reference geodetic network and a construction grid for the construction site, made by the customer;
ensuring the safety, restoration of geodetic points and signs during the construction period, as well as replacing them in case of loss with the determination of a new planned and high-altitude position at the construction site;
production of geodetic marking works and calculation of the required accuracy of geodetic measurements performed at all stages of construction;
geodetic control over compliance with building codes and regulations (SNiP) during the construction process;
geodetic monitoring of the deformation of buildings and structures from the beginning of construction (if necessary);
drafting technical reports on the performed geodetic works during the construction period;
executive surveys of completed construction projects or their individual parts, as well as participation in the acceptance of acts for hidden work, determining the volume of earthworks and conducting control measurements.
The states of geodetic services are determined based on the scope of work, the degree of complexity of the object under construction and the nature of geodetic work. The geodetic service of a construction organization consists of a chief surveyor and 2-3 performers of geodetic work. Employees of the geodetic service report to the chief engineer of the construction organization. In large trusts and associations, geodetic bureaus or groups are created, consisting of several people and headed by a chief surveyor.
In specialized departments and organizations where the volume of geodetic work is relatively small, responsible persons are appointed from among the engineers who organize timely geodetic support for construction work.
The duties of the Chief Surveyor include:
generalization of materials on the state of the geodetic service and the development of measures to improve it;
control of the work of geodetic services of subordinate organizations;
informing the management of the construction organization about the need to suspend construction and installation work in connection with the discovery of a marriage;
participation in commissions to investigate the causes of accidents at construction sites on issues within its competence.
Senior surveyors and surveyors (performers of geodetic works) of construction departments and industrial enterprises should know technical documentation necessary for the production of geodetic works, keep a log of geodetic control and inform the construction line personnel about the results of control.
Senior Surveyors and Surveyors should:
maintain as-built documentation necessary for putting the facility into operation;
control the construction of cast-offs and make axial marks on them;
check the installed formwork and apply axial marks on it;
make an entry in the log of construction and installation works, giving the right to continue them;
periodically control the marking and measuring work performed by line engineering and technical personnel;
monitor the serviceability of geodetic instruments, perform verification and adjustment;
instruct the workers of the geodetic service and the line personnel of the department on geodetic services.
The geodetic service of a construction organization is responsible for the established procedure and compliance with the accuracy of marking geodetic work performed on construction sites.
Therefore, the most responsible work on geodetic support of construction is carried out by employees of the geodetic service. These works include: breakdown of the axes of structures and buildings, creation of an internal grid network; transfer of axes and heights to mounting horizons; production of executive surveys and maintenance of geodetic documentation. However, the performance of functions by employees of the geodetic service does not relieve the line personnel of construction and installation organizations of their responsibility for the quality of work, simple detailed breakdowns, verification levels, measurements of the volume of work performed.
The administration of the construction organization must provide the geodetic service with instruments and equipment, inventory and vehicles, as well as premises for office work and storage of instruments and documentation. Depending on the complexity and volume of objects under construction, various forms of organizing their geodetic services have developed in practice. During the construction of complex objects, geodetic work is carried out by a subcontracting geodetic organization or a specially created geodetic group. At the same time, the contractor approves plans and estimates for geodetic work, controls the progress of these works (in industrial construction), and also performs less complex geodetic work (in civil engineering). In frame-panel construction, the most complex geodetic work is carried out by the forces of a geodetic organization or a geodetic group, and the less complex ones are carried out by a geodetic technician. On the construction of simple objects, geodetic work is carried out by a geodetic group under the management of a construction trust. The control geodetic survey upon acceptance of construction work is carried out by the customer exercising general technical supervision of construction, or by the design organization (on behalf of the customer) at the expense of funds allocated for technical supervision. The state technical supervision is carried out over the correctness of the performance of geodetic work in the design and construction of buildings and structures. It is carried out by territorial inspections, whose task in terms of construction is to control the implementation, quality and cost of geodetic work; issuance of geodetic data and information; implementation of acceptance of completed geodetic and cartographic works; certification of geodetic devices, tools and control over their use in the production of geodetic works.
Geodetic works performed by linear engineers.
Directly at the construction sites, a typical, simple detailed breakdown and geodetic support of individual construction and installation works in compliance with the established accuracy are performed by superintendents and foremen under the control of an engineer or geodetic technician in some cases (depending on complexity). Line personnel, foremen and foremen have the following responsibilities:
provision of geodetic instruments and tools, inventory and transport, as well as premises for office work and storage of instruments, tools and documents;
provision within the construction site of the accepted signs of the geodetic planned-height base, including the main and main axes of buildings, engineering structures, construction grid, as well as permanent signs of points of the working planned-altitude basis;
transfer to the customer under the act of a set of executive geodetic documentation.
In accordance with the "Collection of approximate provisions on the positions of line engineering and technical workers in construction production, the senior foreman must know the procedure for organizing and performing geodetic work, the foreman - the procedure for organizing and performing geodetic work on the site, the master - the rules for working with geodetic instruments, and also be able to produce necessary marking and measuring work.The foreman must be able to use a meter, tape measure, level and plumb line.Persons of line engineering and technical personnel must perform the following types of work:
acceptance according to the act from the surveyors of the management of the fixed axes of buildings, structures, routes, etc.;
the device of cast-offs, their repair or restoration;
selective check of geometric dimensions and shapes building structures;
control of the installation of templates, slopes, guides along the marks and axes, made in nature by the surveyor;
control, installation and preliminary check of the formwork along the remote axes and marks;
breakdown of anchors from axes applied on the formwork;
preliminary check of blocks and metal structures prepared for concreting before final geodetic alignment; - determination of volumes of earthwork, concrete and other works to be paid;
leveling to check the horizontal brickwork, foundation blocks, crossbars, beams;
installation of lighthouses and alignment of the bottom of glass-type foundations according to the marks made by the surveyor;
installation (at the direction of the geodetic service engineer) of embedded metal parts in the foundation for applying axes and marks;
pre-installation of columns in plan, height and vertical;
alignment of building structures directly in the process of installation;
drawing on columns, beams, trusses and other structures of axial marks and marks in the places indicated by the surveyor;
monitoring the safety of fixed in nature axial lines and elevations.
Heads of sites, foremen of work and foremen do not have the right to start construction and installation work before the completion of geodetic breakdowns, drawn up by the relevant act. The act of breakdown, approved by the chief engineer, is a permit for the production of construction and installation works. It is forbidden to carry out work that prevents geodetic control of previously completed work (backfilling of communication trenches, foundation pits, cable trenches, etc.). In the general journal of works (SNiP 3.01.01-85, appendix 1.) the surveyor's instructions are given to eliminate violations of the geometric parameters of the installation of structures, buildings and structures. Building company obliged to fulfill them. They can be canceled only by a written order of the chief engineer of the construction and installation organization.
Project documentation for performing geodetic works.
The construction of buildings and structures is carried out according to projects. The main project document reflecting the principles of organizing future construction is general plan(general plan) for the development of a plot of land, which shows the relative position of buildings, structures and engineering networks, landscaping and landscaping facilities. The topographic plan of the territory, fixing the position of buildings and structures, as well as the terrain after the completion of construction, is called the executive master plan.
In addition to general plans, layout drawings are used to carry out layout work related to the transfer of designed objects to the area, while carrying out work on vertical planning and landscaping of the building site. They are compiled on the basis of the general plan, taking into account the placement of points of the geodetic base on the construction site, and contain the horizontal angles and distances necessary to transfer one or another point, line, or plane to the terrain. To carry out a detailed breakdown of buildings, structures, as well as to resolve other issues related to the performance of geodetic work at a construction site, working drawings are used. They are large-scale and vertical sections of buildings and structures. The main working drawings used in geodetic works include: the title page of the project, the breakdown plan of the main or main axes, the plan of the foundations of buildings, structures, equipment sites, vertical sections, drawings on installation work and technological equipment.
Along with the main characteristic of the architectural and planning solution, the title page of the project contains data on the planned-altitude geodetic reference of the object, the relationship of absolute marks with conditional ones, and also indicates the conditional zero mark (floor level of the 1st floor). The breakdown plan of the main or main axes of a building or structure shows the main axes, longitudinal and transverse main axes characterizing the dimensions of the object under construction, the coordinates of the intersection of the axes, as well as the coordinates of the angles of rotation of roads, power transmission line supports, wells of underground engineering networks. On the plan of the foundations of a building, structure, all the marking axes are presented with references to them of individual parts of the foundation, its dimensions and marks of the upper edge, the depth in the ground, the distance between the axes. The layout of foundations for equipment shows: the location of the axes of the foundations for equipment, the dimensions and depth of their laying with reference to the main axes of the building, structure, as well as the layout data of embedded parts and manufactured anchor bolts. The vertical sections of the building, structure show: the depth of foundations, dimensions and marks of window and door openings, as well as structures and individual elements of the building, structure. Installation drawings of technological equipment are used to perform accurate geodetic stakeouts of the main and auxiliary axes, as well as to carry out design marks. The design documentation, in addition to the materials listed above, includes a number of other documents. For example, drawings for the layout of a vertical planning project (cartogram of earth masses, etc.). In the construction of large and complex facilities, as well as multi-storey large-panel buildings, the presence of PPGR is mandatory.
Safety precautions when performing geodetic works at a construction site.
When performing geodetic works at a construction site, it is necessary to comply with the requirements of the safety standards and rules set forth in the chapter SNiP Sh-4-80 "Safety in construction" and departmental instructions. Persons who have been instructed, issued by order of the construction department, are allowed to perform geodetic work. The risk of injury or injury is determined depending on the conditions of the workplace of the person performing geodetic work. When working on a carriageway with heavy traffic and working at a construction site with a large number of working mechanisms, an observer-worker is appointed.
In earthworks, when digging a deep pit, it is necessary to monitor the steepness of the slopes and the correct fastening of the walls, to avoid undermining. It is forbidden to carry out geodetic work with the installation of the device:
next to the excavator during its operation or under the boom;
on the edge of a pit with steep slopes, as well as on the edge of a shallow pit, at the place of excavation by an excavator, in order to avoid collapse;
under the overhanging soil (visor) or directly on it.
In winter, when soil and concrete are heated by electric heating, geodetic measurements should be made outside such areas, preventing the possibility of electric shock due to the touch of the measuring device to live fittings. In places where electric welding of fittings is performed, or in the presence of current-carrying lines, geodetic measurements are prohibited. If necessary, the power line should be disconnected for the duration of the measurements. When broken down monolithic foundations and executive shooting of the formwork and embedded parts of the foundations is not allowed to walk on the reinforcement, move from formwork to formwork along the spacers in order to avoid accidents. If necessary, walkways or decks should be provided. It is forbidden to carry out marking work on the formwork during rainy seasons. To illuminate the sighting targets of theodolites, the scale of the leveling staff and the device itself, only miner's or pocket electric lights, as well as portable lamps, should be used. It is possible to use electric lamps in the presence of working rubber gloves and shoes.
When moving with devices at a facility under construction, use only fixed ladders and ladders with serviceable steps. You should avoid moving on stairs, the steps of which are not cleared of dirt, snow and ice. It is forbidden to move along the structure, lintels, partitions and walls. Geodetic control of installation inside a multi-storey building should be carried out from places protected by decks with canopies. To lift surveyors to a height, mine lifts, elevators should be used, and where they are not available, suspended, hinged and mobile stairs with fences and platforms should be used.
Transitions with devices and tools from column to column, from crossbar to crossbar are allowed only on convenient scaffolds or portable bridges. When working in dangerous places, the performer must tie himself with a safety belt to a firmly fixed structure.
When working at height with the installation of the device on a panel or crossbar, platforms or a cradle should be arranged for the performer. During welding, measurements on metal beams and crossbars are prohibited. When working on the mounting horizon, all openings and openings must be closed. When transferring the points of the planned basis to the subsequent floors of the building by the method of vertical design, the holes in the ceilings must be equipped with diffusers. When monitoring the installation of the supporting frame, the device must be installed no closer than one and a half height from the structure to be mounted. When performing work on the first floors of the building and near its walls, protective devices should be arranged to protect the performers from objects and materials falling from above. It is forbidden to carry out geodetic work in hazardous areas: near loading and unloading operations, supply of materials and structures by cranes; it is forbidden to walk on crane beams when measuring and straightening rail tracks. At the same time, platforms with a fence and a solid ladder should be arranged at the installation sites of the device.
When surveying, leveling water and sewer wells, measuring with a tape measure or installing a rail inside the wells, you must make sure that there are no accumulations of life-threatening gas in them. Geodetic work at the construction site is prohibited: in case of gusty wind of force 6, heavy snowfall, rain and limited visibility, at air temperature of -30 ° C and below, as well as without helmets and safety belts on the mounting horizon in the installation and work area tower crane, on the assembly site with ice.
When working on a construction site with laser devices, all safety precautions specified in the instructions for use of the device should be observed. Responsibility for non-compliance with safety requirements lies with the management of the construction organization.
2 Geodetic support for the installation of industrial furnaces
Determining the coordinates of the center of large high-rise structures such as blast furnaces
In the practice of engineering geodesy, it often becomes necessary to determine the coordinates of the centers of large high-rise structures that have a cylindrical or conical shape and are a complex device from a number of individual elements of its technological equipment. Such a typical structure includes, for example, a blast furnace.
The difficulty of solving the problem is in order to choose in nature a point that would serve as the geometric center of the furnace, would fix its vertical axis. In practice, such a point does not exist, therefore, one should find in the design of the furnace such an element that could be seen when reviewing the furnace and which would determine its geometric shape.
Picture 1
Such an element can be a grate flange (the main grate ring; Fig. 1, a), which can be shown to the observer in kind by blast-furnace specialists. This grate flange surrounds the blast furnace and is visible from points in the terrain surrounding the furnace.
The geometric center of the blast furnace can be considered the point O, which is the geometric center of the bream. According to the design of the furnace, the geometric centers of the grate flange and the bream must match (be on the same center line). Compliance with this condition during the installation of the furnace is carefully monitored, and the eccentricity of the OO "(Fig. 1, 6) of the collar flange relative to the bream along specifications must not exceed ±35 mm.
It is impossible to check the actual value of the eccentricity for an existing furnace, but it is practically small, so the geometric center of the main grate ring (point O ") can be considered the center of the blast furnace.
Next, the task arises of how to determine the point O in nature. To do this, select points on the ground, for example, A, B, C and D (Fig. 1, c), from which you can see the corresponding points a-a", b-b", d-d" generatrix of the main grate ring. Based on the results of observing the generatrix at the indicated points from the ends A, B, C and D of the bases, it is necessary to obtain the directions AO", BO", CO" and DO", after which Calculate the coordinates of the center of the blast furnace by solving a direct multiple notch.
Geodetic works during the installation of technological equipment
Stakeout of Go, Isontal Axes and Vertical Horizons
The installation of technological equipment begins with the acceptance of the erected foundations, on which the design axes of the equipment to be installed must be accurately placed and clearly fixed, benchmarks laid and their marks determined; the surfaces of foundations and supporting planes must be brought out to the design marks; anchor bolts and embedded parts must be arranged with strict observance of the design dimensions of the axes and marks.
For installation work, it is advisable to mark not the marking axes, but lines strictly parallel to these axes and coinciding with the most important technological lines or planes. In this position, the process of mounting the equipment, installing it in the design position is facilitated. For example, for mounting the guide tracks of the units (Fig. 2, a), it is convenient to take as the mounting axis not the axis of symmetry of the track, but the axis or the vertical one of the threads of the guides; when installing a tank or cylindrical apparatus arranged in a row (along one longitudinal axis), for example, scrubbers or electrostatic precipitators, it is advantageous to choose as a mounting axis a line passing through the extreme generatrices of the cylinders, along which the latter are installed in the design position (Fig. 2, b ). marks; surfaces of foundations and support planes must be displayed.
Figure 2
The choice of mounting axes is made according to the drawings of foundations, installation drawings, drawings of units and technological schemes. At the same time, the possibility of using axes for periodic alignment of units during installation and operation is taken into account.
The installation of equipment in the plan is carried out using a theodolite and stretched strings with plumb lines. The reference planes are set to the design mark using a level and rail, and in a horizontal position using overhead precision levels. To align parts that are at a considerable distance from one another, in cramped places, a hydrostatic level is used, which ensures the accuracy of determining excesses with an error of approximately ± 0.2-0.3 mm.
When installing technological equipment, in addition to conventional geodetic instruments, control and measuring instruments are used (micrometer, probe, indicator, shtihmas, string, precision invoice level with a division value of 10-15 ", etc.).
The micrometer is used to measure the thickness of thin plates and overlays with an accuracy of 0.01 mm. The probe is a set of steel plates of combined thickness (from 0.02 to 0.20 mm) and is used to measure the gaps between the planes. "The indicator is used to measure deviations in the dimensions of the shafts, irregularities in the processing of planes, etc., with an accuracy of 0.01 mm The string is a calibrated steel wire with a diameter of 0.3 - 0.5 mm. With the help of these devices, transverse movements are possible for precise installation of the string along a pointed plumb line or an optical plummet in the alignment of the corresponding axis.The strings are given as high tension as possible in order to reduce the arrow of its sag: for example, for a string with a diameter of 0.3 mm, a tension of 7-8 kg, and for a string with a diameter of 0.5 mm - about 20 kg.
Geodetic breakdowns during the installation of cement rotary kilns.
Geodetic work related to the installation of process equipment consists of a set of geodetic actions outlined in the previous chapters.
The builder and installer, having knowledge of the geodetic techniques outlined in the previous chapters, and owning the basic geodetic tools and instruments, must be able to find a solution to the problem associated with the specific conditions and installation requirements of the particular object under consideration. To do this, you need to know the design geometry of the object being mounted, the technical tolerances for the installation of the structures in question, and correctly provide for the necessary accuracy of geodetic measurements and constructions.
Below is a description of the execution of works related to the construction and installation of cement rotary kilns.
Cement rotary kiln is a cylinder 1, consisting of separate parts-shells, riveted or welded together. Bandages 2 are located along the entire length of the cylinder, with which the cylinder rests on paired support rollers 5. Each pair of rollers is installed on two beds 6, and each pair of beds rests on a foundation plate 7 installed on the foundation (Fig. 3).
Furnaces come in 150- and 118-meter lengths. In the first case, the cylinder is surrounded by nine bandages supported by nine paired rollers and has nine foundations; in the second case, the furnace has six foundations and a corresponding number of foundation slabs, paired support rollers and bandages.
For a 150-meter lechi, the diameter of the expanded part along the casing is 3.6 m, and the narrowed part is 3.3 m; the diameter along the bandages is about 4 m. The axis of the furnace cylinder is not horizontal and has a 5% slope; as a result, the marks of the corresponding points of the extreme bandages with a furnace length of J 50 m differ by approximately 7.5 m.
For the construction of foundations, it is necessary, by already known methods, to break the longitudinal axis OO1 (Fig. 4) of the furnace and the foundation axes perpendicular to it on the ground. The axis of the furnace is indicated by strong concrete signs located in pairs outside the extreme foundations. Cast-offs are installed above the axial signs. With the help of a theodolite, traces of the axis of the furnace are taken out on a cast-off and a thin steel wire is pulled along these traces-risks.
The centers of the foundations are determined using heavy plumb lines suspended at design distances in the direction of the axis to the stretched wire. The longitudinal axes of the foundations, perpendicular to the axis of the furnace, are broken using a theodolite installed exactly in the center of the foundation, by centering a mark on the pipe, indicating the continuation of the vertical axis of the theodolite! under a plumb line suspended on the wire axis of the furnace. Linear segments in the direction of the foundation axis are set aside using a steel comparated tape measure. The axes of the foundations are taken out on a cast-off, arranged along the contour of each foundation, and fixed with remote leading signs located in a zone that is safe for their safety.
Figure 3
Figure 4
When installing the extreme foundations in height, it is necessary to take into account: 1) the difference in the marks of the corresponding points of the extreme bandages, equal, for example, to 7.9 m; 2) the slope of the terrain in the direction of the kiln axis; and 3) the dimensions of the structures located under the center of the kiln.
The installation of the remaining foundations in height is carried out in such a way that their tops are on a straight line connecting the upper points of the extreme supports. All these heights are predetermined by the project and can be brought into nature by a well-known technique.
The foundations of the cement kiln are arranged on a solid foundation to prevent settlement. In order to observe possible settlement at the base of each foundation at a height of up to 0.5 m from the ground, wall benchmarks are laid, for example, from angle iron. Away from the construction site, in soils that guarantee the invariability of the position, a permanent type of ground benchmark is laid, and between it and the foundation line, an intermediate ground benchmark of constant mud is arranged. The location of the intermediate benchmark should make it possible to determine the excesses between it and the control benchmarks laid in the bases of the foundations from one setting of the level.
Assuming the height of the main benchmark to be constant, the excess between it and the intermediate benchmark is periodically determined. The conditional marks of the foundation control benchmarks are determined from the mark of the intermediate benchmark as often as it is provided by the observation program. Invariability: the marks of the foundation benchmarks within the leveling accuracy will show the absence of settlement of the foundations and, conversely, the variability of the marks will show the magnitude of the settlement of the foundations and their achievement of a state of stability after the settlement is attenuated.
Foundation slabs with -frames must be installed on the foundations so that their transverse axes NN (Fig. 6) are on the same straight line and coincide with the axis of the furnace, indicated by a stretched wire with plumb lines; The longitudinal axes of the MM must be perpendicular to it, and the slope distances l between the longitudinal axes of adjacent supports must correspond to the design dimensions.
Figure 6
The marks of paired points Lp and Al on the surface of the slabs must be the same for their slabs and exactly correspond to the design values, and the slabs themselves must have a five percent slope in the direction of the transverse axis NN. The installation of plates is carried out in the following sequence.
Figure 7
The slab is installed in the middle of the foundation so that its axial risks along the NN axis, applied during the factory production of the slabs, exactly coincide with the plumb lines lowered from the tensioned axial wire. To install the slab at the design height, metal spacers are placed under the slab, and the specified slope of the slab is achieved using a mounting wedge 2 (Fig. 7), which has a slope precisely specified by the project, and a calibrated precision laid-on level 3, superimposed on the planed surface of the bed 1.
Checking the design values of the marks of the points Lp and Al is carried out using a level installed on an adjacent slab. The horizon of the tool is determined by the mark of the initial foundation, for which a metal rod with a spherical head is laid in its surface during concreting and its mark is determined in advance by leveling.
To install the rail above points A, two identical metal rods 1.2-1.3 m long with spherical protrusions in the middle are used. Each rod is laid on the planed surfaces of the beds at points 1.3 and 2.4 (see Fig. 6) so that the spherical ledges on which the rail is installed during leveling are above the points Ap, Al, Ap / and Al ".
When installing the plates, the exact observance of the design distances l between the longitudinal axes of the plates is monitored, for which a comparated steel tape measure with millimeter divisions is used. Measurements are made on both sides of the plates.
Before the final installation and fixing of the slabs, all points A on the supports are again leveled with leveling accuracy of class IV, using rails with levels. If the discrepancy between the actual marks and their design values exceeds ± 3 mm, then the position of the plates is corrected.
When installing the rollers, their longitudinal and transverse displacements are eliminated; the axes of the rollers are set parallel to the longitudinal axis of the furnace and the slope of the upper working surface of the rollers specified by the project.
When adjusting the installation of the rollers, the theodolite is centered over the mark of the axis NN of the initial plate and the sighting axis of the pipe is directed exactly along the longitudinal axis NN of the furnace, marked on the opposite end plate. With the correct installation of the rollers, the distances from the axis of the furnace to the centers of the necks of the paired rollers should be the same, and the vertical thread of the theodolite should be aligned with the image of axial marks applied to the middle of special metal bracket-shaped rods installed with their sharpened legs in the centers of the necks of the paired rollers.
The correctness of the distances between adjacent pairs of rollers in the direction of the longitudinal axis of the furnace is controlled by measuring. the distances between. the corresponding upper six points (Fig. 6) of the rollers.
After assembling the furnace body, it is necessary to make sure that it is straight, that is, that there are no vertical and transverse horizontal displacements in the position of the bandages.
The straightness of the furnace from above can be checked by the following methods:
a) leveling of bandages with the installation of a level on the shells in the middle between adjacent bandages;
b) sighting with an inclined beam of a level or theodolite installed on the last shroud. The instrument tube is set at a given angle of inclination by pointing the middle horizontal thread at the reading along the rail corresponding to the height of the instrument placed on the first shroud. In this way, the sighting axis of the tool is set parallel to the axis of the furnace with a slope equal to the slope of the top of the working surface of the bandages. Then the rail is transferred to all intermediate bandages and readings are taken along the rail, which should be equal to the set tool height.
To identify displacements of bandages in the transverse direction ps with respect to the axis of the furnace, two lines should be broken on the ground parallel to the longitudinal axis of the furnace, for which, on the perpendiculars OM and OM / O1M1 and O1M1 / (see Fig. 5), equal segments with a length exceeding by 0.5-1.0 m, the radius is healed, and the ends of the segments are fixed with stakes with a nail-center. The theodolite is centered over the extended point M and the sighting axis of the pipe is directed to the correspondingly opposite point M1. In this way, the line of sight of the pipe will be set parallel to the longitudinal axis OO1 of the furnace. Then, a light, specially made rail with centimeter divisions is successively attached to the end part of the bandages at the points of the largest lateral protrusion of the bandage, holding it in a horizontal position with the help of an applied level, and a reading is made along the rail corresponding to the position of the vertical thread of the theodolite. The difference in readings will show the transverse horizontal displacements of the bands, for example, in the direction to the right of the OO1 axis. After that, the theodolite is moved to the point M, the sighting axis is oriented along the line M / M / 1 and a similar check is performed.
In the absence of a horizontal transverse displacement of the bandage, the readings along the rail attached to the diametrically opposite ends of its outer diameter will be equal. If the correct geometric shape of the bandage is observed, but if it is out of center with respect to the design position of the axis OO1 of the furnace, the algebraic sum of the deviations of readings along the pairwise opposite rails should be equal to zero. Deviation from zero will characterize the deviation of the cross section of the outer rim of the tire from the circle of a given radius.
For the final alignment of the mounted furnace, its cylinder with bandages is rotated around its axis exactly by 180 ° and the chin is repeated again according to the full program outlined above.
3 Geodetic work when arranging pits
When arranging pits, the following basic operations are performed: laying out the contours of the pit, installing cast-offs, sight lines, monitoring the excavation of the pit, cleaning the bottom and slopes, transferring axes and heights to the pit, executive surveys of the open pit. Before laying out the foundation pit, according to the layout drawing, the dimensions of the reserve of the outer edge of the foundation base and the depth of its laying are established. The reserve is necessary to prevent the slope of the pit from collapsing and to install the formwork. The size of the reserve depends on the depth of the pit (at a depth of 2-3 m, it is taken as 20 cm). From the main axes of the building, fixed on the ground or cast-off, the boundary of the inner contour of the pit is broken, taking into account the accepted margin of the outer edge of the foundation base.
From it, the boundary of the outer contour (upper edge) of the pit is broken, taking into account the steepness of the slope. The boundary of the outer contour of the pit is fixed on the ground with stakes every 5-10 m, between which a cord is pulled or a groove is made for 1-2 bayonets of a shovel to indicate the boundary of opening the pit. To lay out trenches for strip foundations, from the main axes of the building to the right and left, values \u200b\u200bare deposited, which in total make up the width of the base of the foundation. Breakdown of pits for columnar foundations is carried out along the main and auxiliary axes, in the alignment of which the centers of the foundations are outlined. From the centers, the contour of the pit is broken.
Control over the progress of excavation and bringing the depth of the pit to the design mark of its bottom is carried out with the help of sights or a level. Permanent sights in the form of horizontal bars are nailed to the cast-off posts at the same height (usually 1 m above the zero mark). On the bar sign the mark of the sight. To determine whether the soil is selected from the pit to the design mark, a portable (running) sight in the form of a rail is installed at its bottom. A line is marked on the rail with paint, the distance to which from the heel of the rail is equal to the difference between the marks of the edge of the bar of the permanent sight and the design bottom of the pit. If the line on the running sight is higher than the cord stretched between the nearest planks, then the soil from the pit has not yet been selected to the design mark.
To determine the actual elevation of the bottom of the pit using a level, first set the leveling rod to a benchmark with a known Hp mark and take it along the reference rail. Then the rail is transferred to the bottom of the pit and a reading is taken. The excess between the benchmark and the bottom point of the pit will be
By adding the excess with its sign to the mark of the benchmark, they get the mark of the bottom of the pit at this point:
Hc =Hp±h. (one)
It is possible to control the achievement of the design mark of the bottom of the boiler at Nkpr by the value of the pre-calculated reading in on the rail:
in \u003d Hp + a-Nkpr. (2)
Soil excavation in pits and trenches is completed with a shortage of 10-20 cm to the design mark, after which the bottom of the pit is cleaned manually based on the results of leveling it in squares. The tops of the squares are fixed with stakes, the upper sections of which (beacons) are located at the level of the design mark, and they are stripped. After cleaning the slopes of the pit with the help of squares with plumb lines or guides, an executive survey of the pit is carried out. Deviations from the design dimensions in the width and length of the pit should not exceed 30 cm. The deviation of the bottom of the pit for foundations from the design ones is allowed no more than ± 5 cm, provided that these deviations do not exceed the thickness of the fill underlying layer. Permissible mean square measurement errors when arranging pits: linear - 1/1000; angular - 45 "and high-altitude - 10 mm. The end of the pit device is confirmed by executive geodetic documentation: an act of readiness of the pit, a scheme for a planned high-altitude survey of the pit, a cartogram for calculating the volume of earth masses.
The transfer of axes to the pit is carried out using a theodolite co. leading points (Fig. 1), fixing the axes, or plumb lines from the points of intersection of the axes, fixed by wires stretched along the cast-off (Fig. 2).
Fig.1. Scheme of transferring the axes of the foundation to the pit using theodolite 1 - theodolite; 2 - leading sign; 3 - cast-off; 4 - roulette; 5 - axial wire; b - axial risk; 7 - movable mark
Fig.2. Scheme of transferring the center axes to the pit by plumb lines: 1 - cast-off; 2 - risks of axes; 3 - axial wire; 4 - beacon blocks; 5 - mooring; 6 - plumb
In the pit, the axles are fixed with temporary signs at the bottom or on the slopes. The transfer of heights to the pit is carried out by a level directly to the bottom or along the slopes. Marks are transferred to deep pits using a suspended tape measure and two levels (Fig. 3).
Fig.3. Scheme of transferring the design mark to the bottom of a deep pit
From Fig. 3 it can be seen that the mark of the bottom of the pit
Hk \u003d Hrp + a - L - c,
where Nrp - mark of the benchmark; L - the length of the tape between the lines of sight of the levels:
Determination of the volume of soil during the development of the pit.
Determination of the volume of soil during the development of the pit is necessary for the operational control of the volume of excavation actually performed. The volume of soil depends on the size of the pit in terms of its depth, the laying of slopes and construction. For pits with different slopes (slope steepness) (Fig. 4, a), you can use the formula for calculating the volume of the obelisk:
where V is the volume of the pit; h is the depth of the pit; a - the long side of the pit below; a1 - the long side of the pit at the top; b - the short side of the pit at the bottom; b1 - the short side of the excavation at the top.
Fig.4. Excavation scheme: a - with different slopes; b - complex configuration
For pits with the same slopes, a formula is used to determine the volume of soil, using which there is no need to measure the upper dimensions of the pit in terms of:
For pits of complex configuration (Fig. 26.6) and with the same slopes, use the formula
where S is the area of the lower base of the pit; P - the perimeter of the lower base of the pit:
P \u003d (a + b + d + e + g + .).
For small pits with slopes with their bottom area up to 100 m2 and depth up to 4 m (in order to simplify the calculation), the volume of soil is determined as the product of the area in the average section of the pit and its depth:
For pits with vertical walls and fastenings, the volume of soil is determined by the formula
Operational control of the volume of earthworks using this method allows to reduce the complexity of this process.
4 How is the roll of a building determined by measuring horizontal angles?
The roll of buildings and structures is measured in several ways: vertical projection using a plumb line, theodolite or an optical vertical sighting device; horizontal angles, angular serifs. The general scheme for measuring the roll (deviation) by the vertical projection method consists in transferring the top point B of the building along the plumb line (Fig. 1, a) to the original horizontal plane. The deviation of point B "from the starting point A of the building characterizes the linear l and angular a values of the roll. The most in a simple way projection is to use a heavy plumb bob. It is fixed at point B, and the deviations of the plumb line from the starting point A of the building are measured with a millimeter ruler in two mutually perpendicular planes of the building and the total linear value of the roll is calculated using the formula:
where h is the height of the building, m.
The angular value of the roll a, which determines its direction, is calculated by the formula:
Due to the inconvenience associated with fixing the plumb line at the highest points, as well as the influence of the wind on the deviation of the plumb line from the vertical, it is used at a height of buildings and structures up to 15 m. At a higher height, as well as to improve the accuracy of measuring the roll, vertical projection upper points are performed using a theodolite. It is installed above the permanent sign on the continuation of the wall of the building at a distance of approximately twice its height. A well-distinguished point B is selected in the upper part of the wall (Fig. 1, b), a telescope is pointed at it, which is then lowered down. A reading is taken along the vertical thread of the telescope on a millimeter ruler, thereby measuring the deviation of point B "from the reference point A by ∆Y. Similarly, the deviation ∆X is measured in another vertical plane and the total linear l and angular α roll values are calculated using the formulas.
Observations of changes in the magnitude of the roll and its direction are carried out by periodic measurements from the same constant signs. When measuring the rolls of buildings and structures up to 100 m high, optical vertical sighting devices are used, which make it possible to determine the components of the roll with an accuracy of 1 mm.
Fig.1. Scheme for measuring rolls of buildings and structures: a - general case vertical projection method; b - using a theodolite; c - by the method of horizontal angles; g - by the method of angular serifs.
When measuring rolls by the method of horizontal angles (Fig. 1, c) from fixed constant signs I-II with a high-precision theodolite, horizontal angles β and γ are periodically measured between the reference directions I-II, II-I (or other constant points on the ground) and directions to the observed top point of the building B. Based on the difference in angles β and γ between measurement cycles, the roll components ΔХ and ΔУ are calculated using the formulas:
The total roll and its direction are calculated by formula (3).
When measuring the roll by the method of angular serifs (Fig. 1, d), strong points I, II and III are fixed around the structure at a distance of at least one and not more than two of its heights, a polygonometric course is laid, and their coordinates are calculated by triangulation. From these points, the coordinates of points A and B along the axis of the structure at its base and at the top (or only at the top) are determined with a right angle notch. When measuring angles, it is taken into account that an error of one second creates an error in determining the roll up to 0.5 mm for every 100 m of distance. To determine the direction to the observed point, the letter "L" or "P" is put near the measured angles, indicating the location of point A to the left or right relative to the alignment from the station to point B. By the difference in the coordinates of points A and B (or one point B) in the initial and subsequent cycles of observations calculate the deviation components ΔХ and ΔУ for a given period of time:
The general linear l and angular a values of the roll are determined by the formula (3). The angular serif method is mainly used in determining the heels of tower-type structures (chimneys, silos, masts and other vertical lines). When observing the rolls of buildings and structures, the maximum measurement error is: for civil walls and industrial buildings- 0.0001 h; for chimneys, towers, masts - 0.0005 h, where h is the height of the building or structure. To measure the roll of columns up to 5 m high, a plumb line is used, and for higher ones, a theodolite is used (Fig. 2). It is installed on two mutually perpendicular directions of the center axes of the column at a distance of 1.5h of its height. Point the vertical thread of the telescope at the upper mounting risk of column A ". Project it onto a millimeter ruler horizontally applied by the beginning of the scale to the lower mounting risk A, and set the deviation value ΔY. This operation is repeated with a different position of the theodolite circle and the average value ΔY is found. Thus in the same way, the average value ΔX is set from another station.The total amount of roll l and its direction (relative to axis A) are determined by formulas (6) and (3)
Fig.2. Column roll measurement scheme.
5 Describe the construction of the staking network on the assembly horizon
Breakdown and fixation of the axes of the structure on the cast-off.
After laying out the main (main) axes of the structure on the ground and fixing them with points of the external marking network of the building, a detailed breakdown and fixing of all building axes are carried out, for which they usually use cast-off.
The cast-off is a temporary structure installed along the perimeter of the building at a distance of 3–5 m from the edge of the excavation. The cast-off can be continuous and intermittent, and according to the material used - wood and metal.
A wooden cast-off (Fig. 1, a) consists of two-meter pillars dug into the ground to a depth of 1.0–1.2 m every 2.5–3.0 m along the perimeter, and edged boards 30–50 mm thick, nailed to the outer side of the pillars so that their upper edges are in a horizontal plane. To comply with this condition, points with the same heights are preliminarily marked on the pillars using a level. The sides of the cast-off should also be parallel to the axes of the structure.
Rice. 1. Cast-off
Inventory metal cast-offs (Fig. 1, b) consist of two-meter racks and metal pipes, which are designed for repeated use. A metal cast-off is installed similarly to a wooden one.
With the help of a theodolite, the main (main) axes of the structure are transferred to the cast-off from the points of the external grid network. The remaining axes (intermediate, installation) directly break the cast-offs on the boards, setting aside the distances along their upper edge with a tape measure. The axes are pre-fixed with a pencil, and after linking the measurements, the final positions of the axes are fixed with paint or a nail.
On the inventory metal cast-off, the position of the axes is fixed by a movable clamp with a plate indicating the name of the axis.
The breakdown of the axles is checked and accepted according to the act. Deviations of the overall dimensions of the structure should not exceed the tolerances adopted for marking work. During the construction process, the position of the axes on the cast-off is periodically controlled from the main (main) axis by measuring with a tape measure.
The cast-off is intended mainly to provide work on the construction of pits and the construction of foundations.
Stakeout works on the initial mounting horizon.
For the erection of the outer part of the structure, an internal grid of the building is created on the initial mounting horizon and securely fixed.
The mounting horizon is a conditional horizontal plane passing through the design marks of the bottom of the mounted structural elements. The mounting horizon of the first floor is the initial one.
The points of the internal grid network are located on the basement floor or directly on the foundation blocks. The number of points and the shape of the internal grid network depend on the size and purpose of the facility, methods of construction and installation work, and other factors. During the construction of relatively small buildings, the longitudinal and transverse main axes are fixed with four points (Fig. 2), in buildings of complex configuration, the main axes are fixed (see Fig. 3). Sometimes for large structures, the internal grid is created in the form of several figures that repeat the contour of the structure. At the same time, the sides of the network are also located parallel to the main axes of the structure, so that the internal and mounting axes can be taken out directly by linear measurements or by the simplest methods of perpendiculars and alignments.
The location of the points of the internal grid network is determined from the points of the external grid network of the structure. For example, in order to take out points located at the points of intersection of the main axes (see Fig. 2), the theodolite is set above point 1 of the external grid network and the pipe is pointed at point 1. Direction 1–1 / is fixed on the initial mounting horizon. Then the theodolite is installed at point 2 and pointed at point 2. At the intersection of directions 1–1/ and 2–2/, the position of the first point (I) of the internal grid network is found and fixed by drawing with a pencil or coloring. Paragraphs II, III and IV are similarly rendered.
The correctness of the breakdown is controlled by measuring distances and right angles. The final positions of the points are securely fixed on the initial horizon with dowels or a core on embedded parts (Fig. 3) and marked with indelible paint.
The high-altitude marking base on the initial mounting horizon is the working benchmarks, which, as a rule, are combined with the points of the internal marking network. The number of benchmarks depends on the complexity of the structure, but there must be at least two. The marks of these benchmarks are determined by the method of geometric leveling from the benchmarks of the external grid network.
Detailed layout works on the initial and other mounting horizons are usually reduced to the construction of internal and mounting axes that fix the planned position of individual structures and elements of the structure. The breakdown of the axes is carried out from the points of the internal center network. When using the alignment method (see Fig. 2), the theodolite is installed at point I of the main axis and the pipe is pointed at point IV. Along the line I-IV, the distances to the outgoing transverse axes are laid down and fixed with risks. Having performed similar actions along the main axis II–III, the second ends of the transverse axes are taken out. Then the axes are fixed with wires or fixed with paint.
Rice. 2. Layout of internal and external grid networks
Rice. 3. Point of internal center network
From the points fixing the main axes of the structure, detailed layout work is usually carried out using the method of perpendiculars. The theodolite is installed at the point of intersection of the main axes (central point) and the pipe is pointed at the point located at the end of the longitudinal main axis. On the sight line, lay off the distance to the transverse axis with a tape measure and fix it. Transfer the theodolite to the point and build a right angle. The resulting axis is fixed with a paint or core on embedded parts. In large-panel construction, mounting axes are fixed with paint in the form of marks (Fig. 4), which determine the planned position of individual structural elements.
Rice. 4. Detailed breakdown of the axes on the mounting horizon
The mark of the mounting horizon is taken out from the benchmarks of the internal grid network by the method of geometric leveling and fixed with horizontal risks or beacon strips.
Transfer of axes to mounting horizons.
The points of the internal layout network of the structure, fixing the axes on the initial mounting horizon, during construction are transferred to subsequent mounting horizons by the methods of alignment and vertical projection. In the construction of low-rise structures, mechanical plumb lines are sometimes used for this purpose.
Plumb lines are suspended on a steel or nylon thread with a diameter of 0.5–1.0 mm. The mass of the plumb line should not exceed half the breaking force of the thread. In long plumb lines to dampen the vibrations of the load, it is immersed in a vessel with motor or transformer oil.
With the alignment method, the axes of the structure are projected onto the mounting horizon. The theodolite is installed at one of the points of the external marking network, which fixes the position of the main axis of the structure on the ground, and the pipe is directed to the second pivot point of this axis or to the stroke of the painting, which fixes the position of the axis on the base of the structure (Fig. 5). Then the pipe is moved in a vertical plane to the desired mounting horizon and the position of the sight line is fixed. The projection operation is repeated at a different position of the vertical circle and the final position of the axis is taken as the average of the two points. When transferring the theodolite to other points of the external grid network, they consistently take out and fix the ends of the main axes along the entire perimeter of the structure.
Rice. 5. Projection of the main axis onto the mounting plate
Geodetic works are an integral part of the process of building design and production, their content and technological sequence are determined by the stages and technology of the main production.
The pace and technology of modern construction require the use of high-quality work force and high precision modern equipment. Few construction sites trust the breakdown process to a foreman with a theodolite. More and more often construction sites geodetic support is outsourced to specialized firms to speed up marking and executive work and remove risks for the work of unskilled personnel. Engineers of the company LLC "TsGiKU » have vast experience in construction support, ranging from cottage construction to Moscow City skyscrapers and complex hydraulic structures. Involving our specialists, we provide the opportunity for both one-time trips and daily stay on construction site. In any case, a team of surveyors will come to you with modern high-precision geodetic equipment and a laptop, which will quickly be able to start solving the tasks assigned to it.
Geodetic support of construction is:
- Creation of the geodetic basis of the object, i.e. fixing on the ground a single coordinate base of the object in order to ensure the geometric correspondence of the objects under construction (roadways, communications, buildings, landscaping elements, etc.) to the project.
- Stakeout of the project in nature (a set of layout works) - stakeout
- main axes of buildings and structures, axes of passages, routes of underground engineering communications, landscaping elements. In addition, the carrying out of the project in nature may include the functions of control and acceptance of stakeout works performed by geodetic services of subcontractors.
- Carrying out control geodetic surveys, drawing up executive schemes. They are carried out in order to control the correct implementation of the project and draw up a reliable executive documentation.
- Maintenance of as-built documentation, as well as control and acceptance of as-built documentation of subcontractors.
Our advantages
Staff of certified cadastral engineers. SRO licenses.
Efficiency in resolving issues.
All work is carried out by our in-house specialists.
The final payment is made upon completion of the work.
We work without intermediaries, so you save your money and time.
More than 5,000 completed objects in Moscow and the Moscow region.
Geodetic support of construction is a set of procedures aimed at monitoring the compliance of design data with existing requirements and construction standards. These works are carried out at the initial stage of design, in preparation for development, as well as during the basic installation procedures. At the same time, high accuracy and the required volumes of measurements are observed.
The considered geodetic control in construction includes such works as:
- tracing the territory - applying the necessary designations, the limits of bulk formations and excavations;
- main layout measures - geo-subject and stakeout of axes and angles, alignment at the construction site, formwork marks;
- filming and executive processes– checking the strength and stability of the object, as well as shooting at each stage of construction;
- monitoring of the manifested deformations of the object - control from the first stage to commissioning.
This list also includes the breakdown and organization of on-site structures, monitoring and verification of the geometric parameters of the object, inspection and correction of the deformations that have appeared. All this is an integral part of the construction, because in the process.
Galtsev Dmitry Alexandrovich
Why is geodetic work necessary? Is it possible to do without them? When are surveys carried out? The land owner must answer these and many other questions long before laying the foundation.
What is geodesy
In a broad sense, geodesy is the science of measuring the earth's surface. She studies the earth's crust-tectonics.
Geodetic construction support is a slightly different area of application of knowledge about the earth. It is necessary in order to choose the only correct place for the construction of the building, on which it will stand for a long time and not interfere with the surrounding buildings, as well as engineering networks. Surveys give a real assessment of man-made and natural conditions construction site.
To be a little more precise, geodetic work is a complex set of actions for marking a site, indicating coordinates, analyzing the relief, linking buildings and other objects on the ground to certain points on the coordinate axis. The work is accompanied by the preparation of detailed drawings with explanations.
Join over 3 thousand of our subscribers. Once a month we will send a digest to your email the best materials published on our website, on the page on LinkedIn and Facebook.
By filling out the form you agree to our privacy policy and consent to the newsletter
Organizations engaged in geodetic work give customers the result of surveys in 2 types:
- digital;
- paper.
Most often, architectural bureaus, where drawings will be transferred later, request them in both versions.
Geodetic work is closely related to such sciences as physics and mathematics. Therefore, when choosing a company to fulfill the terms of reference for surveys at your site, it is necessary to pay special attention to the professionalism of the employees and the equipment used. Geodetic work is regulated by:
- GOSTs - 22651-77, 22268-76;
- legislative acts of the Russian Federation - Government Decree Russian Federation dated March 25, 1996 No. 351, Federal Law "On Geodesy and Cartography".
The list contains only the main documents, but in their work, surveyors refer to more than 2 dozen regulations.
Main tasks
Geodesy belongs to the applied sciences and is used both in private housing construction, and in the process of erecting large objects - residential complexes, factories, shopping centers.
In construction, geodetic work solves several important tasks.
Object location selection
The owner of a land plot (LL) cannot, at his own discretion, choose a place for construction. He only suggests where he would like to lay the foundation, but final decision is accepted after the verdict issued by the specialists of the geodetic company.
In the process of geodetic work, they take into account the relief of the site.
As a result, a plan is drawn up, according to which a specific place for the object is determined. The decision on the depth of laying is made by the designer based on the calculations carried out according to the data Geological surveys. In some cases, on the basis of geodetic surveys, a decision is made to cancel construction at this site. Its parameters may not fully meet the required minimum to start construction work.
Correlation of the future building with existing objects
Buildings cannot be erected randomly. Everyone who is professionally engaged in construction knows this. Therefore, before starting work, it is necessary to carry out surveys on the ground.
Thanks to carefully carried out geodetic work, it becomes possible to bring a model of the future object to the area and correlate it with already built houses and other buildings.
Creating a topographic map
Topographic surveys are one of the types of geodetic works and are often used as independent surveys. Their result is a plan on which:
- all objects are displayed;
- engineering networks are indicated, including underground communications;
- the connection of all objects on the ground is reflected;
- the boundaries of the land are accurately marked.
Such geodetic work is built in 2 stages:
- field - conducting surveys on the memory;
- cameral - analysis of the received data and drawing up drawings with an explanatory note;
The finished topographical plan is handed over to the architect and construction superintendent.
Job classification
Surveys in construction are of several types:
- topographic - geodetic work of this type must be carried out not only before the construction of the site, but also before the start of the reconstruction of already finished objects;
- engineering - the study of the terrain is carried out at the site of the proposed construction;
- marking - placement and preservation of special signs on the ground, tied to the geodetic network, are necessary at all stages of construction to control the quality of the facility being built;
- executive - geodetic work is carried out to compare the drawings of the building with the structure being erected in order to avoid deviations from GOSTs, SNIPs and sets of rules;
- deformation control - such a survey must be carried out after the facility is put into operation in order to track possible changes in load-bearing structures and analyze the impact of the new building on adjacent buildings;
- analysis of the state of underground utilities - specialists cannot say with 100% accuracy how much the building will settle and how this process will affect engineering networks, therefore, they periodically draw up a situational plan based on geodetic surveys.
Despite the fact that everything listed species geodesy is a large-scale complex of works, it is impossible to do without them. Only with this approach to construction, the developer can be sure of the reliability and quality of the structure, and after the completion of work, without problems and delays, put it into operation.
Stages of geodetic works
Any project for initial stage construction relies primarily on:
- relief of the site;
- surrounding infrastructure;
The design bureaus receive the necessary information after carrying out geodetic works. Specialists in this field are the first to start research on land plot, and the last to leave it. Surveys are carried out in 6 stages.
Company Search
From this moment, any construction begins. When choosing a company, you need to pay attention to the following points:
- experience in geodesy - the longer the organization has been operating, the more experience it has;
Geodetic production is such a wide field of activity that it is immediately difficult to single out the main works from it. If we carry out reasoning and determine the root in the word “basic”, then we get “foundations”. It is the basis (foundation) that is considered the beginning of any integral structure. This is probably why everything connected with the creation of a geodesic base is accepted in geodesy as the main work. But it would be so easy. Although there is logic in this. Or maybe, including this, the responsible persons developing industry standards were guided, one of which contains a whole list of basic works (OST 68-14-99).
Regarding this normative document The main works include:
- creation of a planned and high-altitude substantiation of the state geodetic network;
- development, and if necessary, restoration and repair of points of these networks;
- performing various gravimetric surveys and determinations.
Organizationally, all geodetic works are divided into the following two types:
- field work carried out on the ground and related to measurements between geodetic points;
- office work, which is associated with calculations, calculations, graphic images, adjustment and analysis of the accuracy of the measurements performed. And they can all be done indoors. Where, in fact, the name comes from.
List and types of basic geodetic works
Typical types of main work are:
- reconnaissance of preliminary project data on the ground;
- survey of existing points, the degree of their safety;
- placement of a geodetic center of a certain depth into the ground or other surfaces when constructing points;
- the construction of characteristic high-altitude signs indicating the location of points, and the ability, focusing on them, to make observations;
- the actual work on taking measurements to determine coordinates at the centers (methods of triangulation, polygonometry, serifs and others)
- satellite methods for determining coordinates;
- astronomical definitions of geodetic coordinates;
- basic measurements of the original sides;
- leveling between points to determine absolute marks;
- gravimetric observations at points and surveys;
- processing of all results (by types of surveys) of geodetic measurements;
- performance of adjustments of planned leveling geodetic networks;
- compiling information (catalog) about all the data at the points after their adjustment.
As can be seen from this list, all types of basic work include the entire chain of obtaining the main components of state networks from the beginning (reconnaissance and building points) to the final results (leveling and compiling a catalog of their coordinates).
Brief information about the main geodetic works
Reconnaissance has its purpose setting out points geodetic points as they say in kind in accordance with the scheme of the preliminary technical project. During these works, the final places for laying future geodetic points, the depth of laying and types of centers, character heights are calculated. Based on the results of the reconnaissance, a corresponding report is attached with conclusions on the technical, economic and organizational aspects of improving the preliminary project for the creation of a geodetic network.
Surveys of existing points are carried out as necessary to carry out measurements on them and depending on the safety of the state of the entire geodetic point, including centers, signs, signals.
The position of each of the centers of the sign is fixed by special optimal designs developed and approved by the instruction. Depending on the physical and geographical location, the climatic component, up to eleven planned types and up to five leveling benchmarks are distinguished, including in rocks and building walls.
The construction of external sighting and landmark marks above the points should help ensure the necessary accuracy of the measurement work. Special calculations help determine the correct signal height. And the reliability of the design is achieved by the use of durable materials, form stability and reliability of building connections in it.
Upon completion of the construction of the point on it, measurements are made in directions to adjacent points. At different times, using different instruments and techniques, observations are made on them.
The oldest method is considered to be the astronomical method with the determination of the azimuth of the sides and coordinates in the form of latitude and longitude.
Traditional, one might even say classical, methods are used to develop all justification networks. These include:
- triangulation method;
- trilateration method;
- polygonometric moves;
- geodetic lines.
For linear measurements of distances between points in Soviet times, basic instruments were used. With the use of more modern and accurate devices such as radio and light rangefinders, the name of the base side was preserved behind the measured sides of geodetic points.
Other measurements, instruments and methods determine the heights of separately constructed leveling networks. The main methods of leveling include;
- trigonometric;
- barometric;
- geometric.
With the development of satellite geodesy, new possibilities of autonomous methods for determining coordinates have appeared. The combination of different methods, both terrestrial and satellite, makes it possible to improve the quality of the construction of geodetic networks. And, in the end, with its help, unified coordinate systems for our planet were created.
Gravimetry can be called a separate section in geodesy. The solution of its practical tasks is considered to be observations at the points of reference gravimetric and geodetic networks, determination of the force of gravity, compilation various cards, gravimetric surveys. The last of these tasks are divided into the following types:
- ground;
- aerial photography;
- bottom survey;
- ice.
All the above methods of measurements and surveys are pre-processed. Its essence lies in the generalization and primary control of geodetic works. If we consider in more detail, we highlight the following in the primary processing of calculations:
- verification of field books and journals;
- detection of gross errors;
- preliminary calculations in "two hands";
- checking the compliance of the measurements and preliminary calculations with the required accuracy of the work performed;
- preparation of all data for the start of network adjustment according to the design scheme.
Network adjustment is performed in order to obtain the most reliable values of the required quantities. At the same time, this process requires, as they say, not only necessary, but also sufficient, that is, an excessive number of measurements. There are two methods of least squares adjustment:
- parametric;
- correlated.
After the network adjustment is completed, a report is generated in the form of a catalog. It contains information on the following quantities:
- types of jobs;
- execution methods;
- the resulting accuracy of work;
- the system of coordinates and heights in which the work was carried out;
- absolute values of planned coordinates and elevations;
- lengths of the sides of the network and directional angles;
- names, designations, locations and outlines of points;
- network diagram.
Controversial autoblogger Eric Davidich sentenced
Schiff leiba kun baruch who are they
Hype pyramids Operating financial pyramids
What will happen to the dollar (ruble) in the near future - forecasts and expert opinions
Forecast of the euro exchange rate for the near and distant future Forecast of the euro exchange rate for the beginning of September