Study on some problems of settlement calculation with secant modulus method and its modification

Secant modulus method (SMM) is a new method to calculate foundation settlement in recent years. The reasons responsible for distinct difference between predicted settlements with SMM and e—p curve method are analyzed, which are due to the fact that the reference configuration defining strain differs from the equilibrium state of self-weight stress, and that the relation of compression strain to pressure is assumed to be a hyperbolic curve. A new compensation factor is put forward to correct the results predicted by SMM. According to oedometer test results of eight soil samples, the compensation factor is found to decrease with increasing depth. Through a case study, the results obtained with e—p curve method, SMM and modified SMM are contrasted in detail and the reasons responsible for the difference are explored. For soils in accordance with hyperbolic model, the presented modified SMM is not only convenient for computer-aided analysis, but can also improve accuracy.