Engineering surveys in construction
The execution of any construction project involves an analysis of the existing conditions.
For construction, there are two most important studies that serve as the basis for design and give a broad picture of the existing conditions.
I Engineering and geodetic surveys
Why do we need engineering and geodetic surveys?
Engineering and geodetic surveys or - simply geodetic survey, geodetic surveys. Needed to obtain information about relief and the situation of the area, serve as the basis for design, and for other types of surveys and surveys.
Who performs geodetic surveys?
Engineering and geodetic surveys can be carried out both by an individual specialist with an appropriate certificate and equipment, conducting business activities, and by an organization that has such specialists on its staff. Modern equipment for surveys are electronic tacheometers. As a rule, two people are enough to carry out the work. The timing depends on the complexity of the terrain, the amount of work and weather conditions.
What should include engineering and geodetic surveys?
Topographic plan at a scale of 1:500 with plotted:
the boundaries of the site under consideration and the boundaries of nearby sites (with applied cadastral numbers),
contours of buildings and structures located in the survey spot with an indication of their function (residential / non-residential),
all engineering networks, both above ground and underground, indicating red lines along the streets,
trees and shrubs, fences and fences, protected areas of forests and coastlines,
contours and designations of embankments and cuts,
vertical marks in the accepted system of heights (the standard for the CIS countries is the Baltic system of heights),
fixed points in the accepted coordinate system (most often every 50 m for a scale of 1:500),
directions of the world,
symbols that explain what is shown with lines of each type and color
A stamp must be placed on the topographic plan, which indicates:
the name of the organization that performed the survey,
full address of the object,
surname and initials of the specialist,
accepted coordinate system,
accepted system of heights,
shooting date,
stamp that the footage is suitable and up to date.
Also, it is good manners towards the designers to issue survey results in electronic form for quick integration and terrain modeling.
topographic plan example
II Engineering-geological surveys
What is engineering and geological surveys for?
Engineering and geological surveys or simply - geological surveys or geology - colloquially, are necessary to draw up a complete picture of the existing:
soils, their types, thickness (thickness) of layers, physical and mechanical characteristics, which are needed primarily to calculate their bearing capacity. This is important for the calculation of foundations.
water, its level in relation to the surface, its composition in relation to aggressiveness in relation to building materials,
seasonal changes in the construction area, taking into account the information accumulated over the years on this region.
Who performs geotechnical surveys?
Geotechnical surveys are carried out by specialized organizations, which employ specialists with relevant certificates, as well as specialized drilling equipment and a testing laboratory.
What is the correct procedure for conducting surveys?
The right stage for carrying out field work will be the stage when you already have geodetic surveys of the territory and a preliminary design or preliminary development intention, which will give an understanding of the location of the future building, its configuration and number of storeys. Since different objects will require a different degree of foundation research. Simply put, the greater the number of storeys of the building, its weight, the deeper the wells for obtaining samples. As a rule, for low-rise buildings, the investigated thickness lies within 10 m . The number of wells depends on the configuration of the building, but preferably at least 3x , in order to get 2 sections within the building area.
It should be taken into account that wells are drilled with motorized vehicles. And you should organize an entrance for her to the construction site.
The timing of the field work depends on the complexity of the terrain, the amount of work and weather conditions. Laboratory work and report writing - approximately 2 weeks , depending on the volume.
What should include geotechnical surveys?
After field and laboratory tests, - technical report on engineering and geological surveys is issued, which consists of 3 parts:
1. Explanatory note of the technical report:
geological and lithological structure,
hydrogeological conditions,
physical and mechanical properties of soils,
conclusions,
list of literature and normative documents.
2. Text attachments of the technical report :
description of engineering-geological workings,
a summary table of the results of laboratory determinations of soil properties according to the EGE,
normative and design characteristics of soils,
results of chemical analysis of soils,
results of chemical analysis of water,
assessment of potential flooding of the territory,
information about the methods and means of measurement.
3. Graphical applications of the technical report :
layout of wells and section lines,
engineering-geological sections,
symbols for cuts.