Engineering and topographic-geodetic surveys

• Topographic survey (scale 1:200, 1:500, 1:1000, 1:2000, 1:5000 И 1:10 000) is a package of engineering and geodetic surveys which results in building of detailed area plan. Topographic survey is carried out in several stages which allows to study thoroughly an area and its features:
• Preparation step
• Receipt of technical assignment;
• Collection and analysis of materials for the assigned area on previously performed geodetic surveys;
• Preparation of a program for Topographic-geodesic works considering Customer technical assignment requirements;
• Obtaining a permit (implementing a registration) for the execution of Topographic-geodesic works.
• Field stage
• Field reconnaissance;
• Implementation of a package of field works consisting of development of geodetic control networks using GPS including geodetic networks for special purposes; development of horizontal and vertical control survey networks; topographic survey including survey of above-ground and underground structures;
• Implementation of required scope of calculating and other works for preliminary processing of the received materials and data in order to monitor their quality, accuracy and completeness
• Office stage
• Formation of digital terrain model (DTM), preparation of topographic plans and profiles
• Coordination of the completeness and correctness of drawing utilities on topographic plans of utilities
• Drawing up and transfer to Customer a technical report containing the necessary annexes based on the results of the work performed (topographic and geodetic works) and original engineering and topographic plans (in graphical and digital form)

• Topographic map (scale 1:500, 1:1000, 1:2000, 1:5000 и 1:10 000) contains complete information of relief, location of rivers and lakes, soils and vegetation. The plan is a large-scale drawing depicting the required piece of land with symbols. It maintains a constant scale in all directions, is built taking into account the curvature of the surface levels
• At its core, the plan retains the properties of the map and is its integral part. Before planning a construction site of any scale, a project documentation shall be prepared, which includes a topographic map and a plan detailing individual objects, such as communications.
• Creation of a map and plan is required in such cases:
• Building permit;
• Design and connection of communications;
• Reconstruction of a residential or non-residential building;
• Registration of land ownership or long-term lease;
• Drawing up a landscape project for any site.

Our company has extensive experience in various types of geodetic surveys, including executive surveys of underground communications. Topographic survey is conducted using modern instruments by highly qualified specialists. It is carried out during the construction of engineering communications before the trenches and pits are filled. Determining the location afterward would be extremely challenging. During the survey, all types of underground installations must be captured: turning angles, inspection hatches, chambers, all locations of changes in pipe slopes, their diameter, places of branching and connections, etc. Each type of engineering communication has a specific set of objects that are mandatory for surveying.

Linear structures, together with certain technological devices designed for transporting various liquids and gases, as well as transmitting energy, are considered engineering communications. Traditionally, they are divided into two groups: aboveground and underground communications. Their complexes are also called engineering networks, and existing individual communications are also referred to as routes or installations.

If the land plot previously had laid engineering communications, but construction or reconstruction of an old building is planned on it, some installations may be exposed by new trenches. Any changes that will occur in the subsequent period must be captured and documented. An important aspect is the planned identification of underground communications. For built-up areas, the starting position is taken from solid points of capital construction or from points of the reference geodetic network. For undeveloped areas, it starts from equipment points for executive survey or also from points of the reference geodetic network.

Field routing is a transfer of designed route to the terrain specifying its changes and fixing out. The route shall be identified on the ground by position of its main points:


1) tangent points of the curve (TP)
2) top angles of curvature (TA)
3) middle of the curve (MC)
4) points of crossings with axes of structures

These points on the ground are fixed with signs. The type of sign depends on the required period of their preservation on the ground. Leading points are fixed with landmarks. Transfer of the route from the map to the terrain is carried out either according to the coordinates of its main points, or according to the data linking the route to terrain objects. The coordinates of points and anchor elements are determined graphically on the map. Therefore, the accuracy of transferring the main points to the terrain is mainly determined by the scale of the map. After transferring the route points to the terrain, theodolite or polygonometric passages are laid, which include all the points mentioned. During these works, between the curvature angles, “hanging” and measuring lines are carried out, horizontal angles are measured, and stationing are laid out with marks of plus points and diameters. When laying out the stationing, the lines are measured with a measuring tape (line) in one direction, comparing the values with cross-wire meter. Pickets are fixed with wooden stakes. A “guard stake” is set up nearby and a trench is made. The route beginning is designated PK0. A number of the next stationing means the number of hundreds of meters of the route from its beginning. Characteristically, a relief point is marked with plus points, which indicate the distances to the nearest pickets, for example:

 PC5+68.

 When placing pickets on sloping sites, corrections for the slope are introduced into the measured distances.

 Laying out near the curvature angles has its own specifics.

The main elements of the curve:

 TP = TA — Т TA = TP + К MC = TP + К/2

 Control:

TP = TA-D + T, SK = TP – K /2

• Topographic map (scale 1:500, 1:1000, 1:2000, 1:5000 и 1:10 000) contains complete information of relief, location of rivers and lakes, soils and vegetation. The plan is a large-scale drawing depicting the required piece of land with symbols. It maintains a constant scale in all directions, is built taking into account the curvature of the surface levels
• At its core, the plan retains the properties of the map and is its integral part. Before planning a construction site of any scale, a project documentation shall be prepared, which includes a topographic map and a plan detailing individual objects, such as communications.

• Creation of a map and plan is required in such cases:
• Building permit;
• Design and connection of communications;
• Reconstruction of a residential or non-residential building;
• Registration of land ownership or long-term lease;
• Drawing up a landscape project for any site.

Under the deformations of buildings and structures we understand the change in the spatial position of the points of the structure, its parts or the entire structure as a whole. These changes occur in time under the action of external and internal forces.
Buildings and structures on soil foundations can move in a horizontal plane, which is called shear, or move vertically. Such displacements directed vertically upwards are called uplifts, and downwards – precipitation. In addition, as a result of unevenly flowing precipitation along the perimeter of the structure, its main planes can slope.

 Such slopes are called rolls.
Uneven settlements occur primarily as a result of different pressures of parts of the structure and unequal compressibility of the soil under the foundation, which, in turn, causes various kinds of displacements and deformations in the structure structures.
The results of practical field observations of precipitations and uplifts of structures are one of the main materials characterizing the foundation bed stability and the foundation reliability. Carrying out high-quality high-precision measurements of spatial displacements of structures makes it possible to obtain reliable information about such important parameters as the depth of the compressible thickness of the foundation soil and the attenuation of settlements over time, to establish a practically limit for uneven settlements, after which strength is impaired and dangerous rolls, distortions, cracks appear. Finally, the results of studies of precipitation and uplift of structures are a good basis for the development of certain empirical methods and techniques for fast and reliable settlement prediction.
Systematic instrumental measurements of precipitations and deformations of structures are of great practical and scientific importance.
The practical significance lies in the fact that the measurement results are used as source material to characterize the stability of the foundations and the entire structure as a whole, allow to plan in advance measures to eliminate the causes of deformations, carry out repairs, etc.