Description of the problem

In many cases, it is required to determine the settlement under an abutment, a bridge pier, a building core or a raft of thick thickness. In these cases, the foundation will be assumed as rigid foundation.

As an example for rigid rafts, consider the rectangular raft of a core from concrete walls shown in Figure 55 as a part of 93.0 [m] structure. The length of the raft is L = 28.0 [m], while the width is B = 25.0 [m]. Due to the lateral applied wind pressure, the raft subjected to an eccentric vertical load of P = 142000 [kN]. Figure 55 shows section elevation through the raft and subsoil, while Figure 56 shows a plan of the raft, load, dimensions and mesh.

It is required to estimate the expected settlement if the raft is considered as perfectly rigid.

 Example 23: Settlement calculation for a rigid raft subjected to an eccentric load