Having set the theodolite in the working position, they lead a vertical thread to the edge of concrete along the silos forming below and, lifting the pipe, check the verticality of the wall. If the edge of the wall leaves the vertical thread, then there is a deviation from the vertical.
This is checked in the second position of the circle to avoid the influence of instrumental errors. To determine the linear value, the angular displacement is measured in two positions of the circle and the deviation from the vertical is calculated.
According to the results of the audit, they make up an executive scheme.
Clear marks are applied to the brackets (if the edges of the brackets are clearly visible, then you can do without marks). Then choose oriented points. The distance to them should be no less than from theodolite to the far bracket. Tagging points can be tags applied to any local objects, the safety of which guarantee the entire period of concreting of the structure.
The theodolite is installed on the fixed points and measure the horizontal angles between the oriented directions to the brackets with several techniques (the number of controlled points is selected in advance). These angles will be initial for further observations in the concrete process.
When checking the verticality, the same horizontal corners are measured and compared with the corners measured before the start of concreting. By the difference in the angles of the first and next cycles, the angular size of the displacement of brackets is determined, rigidly connected to the circles and formwork, and calculate the angle of the angle for each bracket.
In this case, take into account the sign of displacement relative to the line of visualization. The results are applied to the executive scheme. You should dwell on the value of the results of geodetic measurements during the construction of structures in sliding formwork.