带帽桩复合地基复合桩土应力比的计算及影响因素分析

在分析带帽刚性桩复合地基试验成果的基础上,提出复合桩土应力比的概念,以合理反映带帽桩复合地基的力学性状。以土力学和弹性理论为基础,基于合理假定,采用等沉面的思想,考虑复合桩体发生上、下刺入变形现象,推导出能够反映层状不均质地基和带帽桩复合地基空间三维沉降变形特征的复合桩土应力比隐式计算公式。通过工程算例,分析了桩体中心间距、桩长、桩帽尺寸、垫层变形模量、下卧层土体变形模量、桩帽间土体变形模量和静止侧压力系数等因素的影响,提出了利用复合桩土应力比进行带帽桩复合地基按桩帽间土体沉降量控制优化设计的思路。

Calculation and analysis of composite pile-soil stress ratio of composite foundation with capped rigid pile

The conception of stress ratio of composite pile-soil was put forward on the basis of test data of composite foundation of rigid pile with cap to describe its mechanical behavior.Based the on soil mechanics,elastic theory and some reasonable assumptione,adopting the method of the equal settlement section,considering the pemetration of top and fir of pile,the calculation formula of composite foundation with capped rigid pile was proposed,which showed the characteristics of layered soil and its 3D settlement deformation.The spacing and length of pile,size of pile cap,modulus of cushion,modulus of underlying soil layers,modulus of soil besides pile caps and K0 were discussed with practical engineering example.It was shown that the optimized design of the composite foundation with capped rigid pile could be performed with the method.