What are the forms of concrete internal support structure?

There are two commonly used internal support systems: plane support system and vertical diagonal support system.

The plane support system can directly balance the lateral pressure on the support walls at both ends of the support, with simple structure, clear force and wide application range. However, when the length of members is long, the influence of plane bending and elastic compression on the displacement of foundation pit should be considered. In addition, when the horizontal force between the two sides of the foundation pit is very different, the displacement of the retaining wall will affect each other through the horizontal support, so it is necessary to adjust the calculation model of the retaining structure.

The function of vertical diagonal bracing system is to transfer the pressure on the upper part of retaining wall to the foundation below the excavation surface through diagonal bracing. The construction technology is as follows: after the retaining wall is completed, the middle soil layer of the foundation pit is excavated by sloping, then diagonal braces are installed, and then the soil slopes left around are excavated. For the foundation pit with large plane size, irregular shape and shallow depth, it is simpler to adopt vertical diagonal bracing system, and it can also save supporting materials.