A simplified prediction method for additional stress on underlying layer of rigid pile-net composite foundation

Abstract

To propose a simplified semi-empirical method for predicting the additional stress on the underlying layer of the rigid pile-net composite foundation, a finite element analysis, which verified by a series of field tests and model tests, are carried out. Focusing on the equivalent entity method recommended by Technical code for composite foundation, the equivalent frictional resistance coefficient, which is a key factor affecting the additional stress, is deduced through the static balance theory and β-method. Finite element analyses, including 432 tests, are conducted to analyse the effect of pile length, pile spacing, thickness of cushion layer, embankment height and geological conditions on the key coefficient. Then, a simplified semi-empirical model for predicting the key coefficient as well as the additional stress is proposed based on numerical results. The accuracy of the proposed model is verified by the good agreement between the experimental results and numerical results.