基于能量法的高承台桩基沉降计算方法

Settlement calculation of pile foundations with elevated caps by energy method

为探讨高承台桩基的沉降计算方法,考虑高承台群桩中各基桩的相互作用,首先基于Cooke原理推导得到基桩桩侧单位厚度土的等效刚度系数;其次,从能量传递的角度建立承台-桩基的平衡方程,并联立承台-桩基变形协调关系以及桩端边界条件,利用能量法对基桩桩身轴力与位移进行求解,从而得到高承台桩基沉降计算方法,编制相应的计算程序。最后,利用该方法及计算程序对某工程中的高承台桩基进行计算。研究结果表明:采用本文方法所得计算结果与实测结果较吻合,验证了本文计算方法的合理性。

In order to investigate the computational methods for settlement of high-cap pile, an identical stiffness coeffieient of surrounding soil with unit thickness was derived based on Cooke principle to simulate the interaction among each pile of pile group. Equilibrittm equation of cap-pile was constructed in the viewpoint of energy transmission. Deformation compatibility of cap-pile and boundary conditions at pile end were incorporated to solve axial forces and displacements of pile by using energy approach. Thus a novel calculation method for settlement of pile foundation with high cap was developed and the corresponding program was written. Finally, this method and program was utilized to calculate a high-cap pile in an engineering project. The results show that the results computed by this technique are in accordance with those measured, which verifies the reasonability of this method.