Deformation Behavior of Rigid Pile Composite Foundation with Variable Stiffness

Abstract

According to the standard design, the bearing capacity of soil between piles of soft soil rigid pile composite foundation is often too high, and the settlement corresponding to its design bearing capacity is greater than that of composite foundation. In practice, this situation is impossible. Therefore, the bearing capacity of soil between piles can not be brought into play according to the design. The main reason is that the relationship between pile and soil deformation coordination is not considered. In order to reveal the internal essence of pile-soil deformation coordination and the problem that the bearing capacity of soft soil is excessively used, the hyperbolic tangent modulus method is used to calculate the P-S curves of pile and soil respectively. Then the P-S curve of composite foundation is superimposed to establish the deformation coordination relationship between pile and soil, so as to analyze the load sharing between pile and soil. After analysis, it is found that when designing according to the code method, the bearing capacity of soft soil is usually used too high and the bearing capacity of pile is designed too low. For example, the bearing capacity of single pile or its strength is insufficient, which is easy to lead to the damage of pile and composite foundation. In view of the shortcomings of the standard method, it is proposed that the reasonable design of soft soil rigid pile composite foundation should consider the relationship between pile and soil deformation, and the bearing capacity of soil between piles should be determined according to the P-S curve and the load corresponding to the corresponding settlement. The design and calculation method of soft soil rigid pile composite foundation considering the coordination of pile and soil deformation established in this paper can provide guidance for future design..