Geodetic surveys today are widely used in various industries. One of these areas is land and cadastral relations. In industry, without such work, mining is impossible. But geodetic works in construction are especially important. This is due to the need for high measurement accuracy in the design and construction of both industrial facilities and civil buildings. That is why the importance of geodetic works in construction is difficult to overestimate.
General content of the concept
The result of engineering and geodetic surveys is information about the nature of the relief of the area where construction work is to be done. They are de alt with by specialized companies whose task is to build and develop survey networks (planned and high- altitude), determine the coordinates of key points of land boundaries, conductand timely update the topographic survey, identify and mark on the maps the existing engineering communications (both underground and surface).
In their activities, surveyors rely on the source data, which contain topographic maps of the area. The process of operation of the object also implies the implementation of a number of specific engineering and geodetic tasks. Almost everywhere, it is required to process and refine design and working documentation, carry out tying and layout work, control the geometric parameters of buildings, and conduct as-built surveys.
In addition, geodetic work in construction includes the task of monitoring the settlement and deformation of the earth's surface and construction objects, including as part of monitoring hazardous natural processes. They are also in charge of measuring work, that is, they determine the parameters of buildings and a variety of architectural forms. In addition, they control the verticality of structures and columns, align the crane runways. Installation of any complex type of equipment is not complete without such work.
Types of geodetic works in construction
What are the applied directions of modern geodesy? There are a considerable number of them. At the facility, specialists create a reference geodetic network, it is tied to absolute elevations and to the coordinate system existing at the given location. The construction site is planned in vertical and horizontal directions, the necessary volumes of earthworks are calculated, in kinddesign axes are taken out outside and inside the building. Construction objects are planned vertically, their area, volume and perimeter are determined.
Geodetic works in construction are used in the installation of factory equipment and the installation of complex instruments. An important place is given to them in the construction of railway tracks and crane rails. They are also carried out during the construction of linear structures, columns, towers, various antennas, cameral and field tracing. This type of work is also in demand in the field of underground utilities.
After construction, an executive survey is carried out, which reveals all deviations from the decisions specified in the project. Control over the geometric parameters of the object is also carried out during the construction process itself. Modern methods for the production of geodetic works allow you to create executive plans and diagrams in electronic form or in the form of 3D models.
What are they made of
Any geodetic work in construction can be divided into three main stages. The first of them (preparatory) includes the formation of technical specifications, which must contain a list of the most important points. We are talking about the location of the future object on the territory and in space, its size and volume. The following is a list of work to be done. It may consist of a topographic survey, a breakdown of the territory, executive survey, measurement work or control.
The customer can add a number of other wishes to the list. He leads and controlsgeodetic works in construction. At this stage, all communications, both main and auxiliary, and their relative position are specified. In addition to the scope of work, the timing of their implementation and the form in which the report will be formulated are indicated.
At the preparatory stage, the necessary technical documents are collected and prepared. These include copies of existing topographic maps, site plans with marked boundaries of sites and construction sites, master plans with outlined outlines of future facilities.
The contract drawn up for the survey completes the preparatory stage of geodetic work. Next, you need to stock up on data on the results of engineering work carried out on the construction site earlier. Without them, the task becomes much more difficult. Based on the terms of reference, the work organizer develops a plan for future events, taking into account all existing conditions and restrictions.
Practical side of things
At the second stage of work - the field - surveyors conduct reconnaissance of the area. This is a rather complicated process, because often the real conditions can differ significantly from those indicated in the documents. The most responsible procedure of this stage is called topographic survey. It belongs to the most famous and popular types of engineering surveys and is carried out on different scales - from 1:500 to 1:5000.
Based on its results, surveyors have the opportunity to draw up a topographic plan. Modernactivities in the field are accompanied by the use of the latest technical means in the form of electronic and optical theodolites, laser levels, etc. Their use not only facilitates the hard work of surveyors, but also increases the accuracy of measurements by an order of magnitude.
What the plan contains
On the topographic plan drawn up, any elements of the terrain should be displayed, which include buildings, relief differences, and large objects of vegetation. All existing underground communications, such as pipelines or electrical cables, must be fixed without fail. If this point is not given sufficient attention, the consequences can be very serious. That is why the preparation of a topographic plan is the task of a highly qualified specialist.
Topographic survey is useful not only for builders. It is indispensable for specialists in landscape design and those who have applied for a permit for building a land plot. Thus, survey data is required almost everywhere when it comes to land management procedures.
Last step
The final stage of geodetic work is called cameral, or office. On it, specialists refine the data obtained during field work, and all the calculated parameters. Processing requires a significant flow of information, which implies the attention and high qualifications of the performers.
The technical report on the work done in the geodetic sphere is called explanatorya note and contains a lot of numbers, drawings, diagrams and other data with the results of the work done. All documentation, properly executed, is transferred to the customer.
Who leads the process
The preparatory stage of work at the construction site is usually in charge of the customer-builder, the same tasks that relate directly to the construction process are most often performed by the contractor or general contractor. The customer and the general contractor may be representatives of different organizations, but sometimes they cooperate within the same investment and construction company.
Organization of geodetic works in construction depends on their complexity and volume. If a subcontractor is involved in the construction of the facility, which includes geodetic specialists, all this work is performed by them. If we are talking about a small object that does not involve complex surveys, geodetic tasks are solved directly by the builders themselves.
JV "Geodetic work in construction" - what kind of document?
Like any other type of work, geodetic surveys must be regulated. The purpose of this is to ensure the unity and accuracy of measurements and the transfer of data from field conditions to drawings and documents. Such regulation is reflected in the system of SNiPs (building codes and regulations), as well as other higher standards adopted at the state level.
There isseveral basic documents that determine both the content of various geodetic surveys in the field of construction, and the procedure and forms for their implementation. The leading one is SP 126 13330 2012 "Geodetic works in construction". The abbreviation SP stands for "building rules". This document is an updated version of the previously adopted SNiP "Geodetic work in construction" No. 3.01.03-84. They are the main guide containing instructions regarding all issues of organizing this type of work. As in the SNiP "Geodetic work in construction", they spell out any nuances related to the procedure for creating a stakeout base, acceptable accuracy, etc., set out numerous requirements for measurement error standards in the geodetic sphere and various methods of transferring marks.
In addition to the joint venture "Geodetic works in construction", other reference manuals serve as a guide for employees of the geodetic service. These can be developed for different areas of application and relate, for example, to the composition of as-built documentation and its content, the use of special instruments in geodesy, measurement procedures with a description of the necessary technologies, as well as the necessary recommendations related to geodetic work on the construction of high-rise and multifunctional buildings.
What is PPHR
Take into account all the recommendations contained in the set of rules "Geodetic work inconstruction", must be in the preparation of a project for the production of geodetic works (PPGR), the presence of which is mandatory if we are talking about the construction of a large and complex facility or a building with a height of 9 floors. Such a project contains the scope and methodology for conducting surveys, planned deadlines, financial and organizational issues.
The contractor himself can develop a PPGR or he entrusts it to a specialized organization in agreement with the customer. The project must be formed and go into production no later than 2 months before the start date of work.
