基于桩侧阻概化模式的基桩均化附加应力系数研究

基于群桩Mindlin应力解附加应力场和群桩基础变形分布特征,考虑承台和上部结构刚度对沉降变形的均化效应,在现有Mindlin解均化应力分层总和法计算群桩基础沉降基础上,提出任意布桩模式下基桩均化附加应力系数数值计算方法。针对特定侧阻分布概化模式给出不同长径比、不同桩距条件下的基桩均化附加应力系数表格,为手算群桩基础沉降所需的均化附加应力计算提供有效的简易方法。提供的均化附加应力计算方法计算群桩沉降通过工程实例验证,与Boussinesq实体深基础计算法和等效作用计算法比较,其沉降计算值与实测竣工沉降值较为接近。

Homogenized additional stress coefficient of foundation piles based on generalized mode of pile shaft resistance

Based on the stress field calculated by the Mindlin stress theory with the pile diameter effect considered and the existing Mindlin homogenization stress summation method for calculating the settlement of pile group foundation, the deformation behavior of the pile group foundation as well as the homogenization effect of pile cap and the superstructure stiffness on the settlement deformation, the homogenized additional stress coefficient of foundation piles under the arbitrary pile distribution mode is proposed. In the light of the generalized model for specific shaft resistance distribution, the pile-pile homogenization stress coefficient table is given under different ratios of length to diameter and different pile spacing, so as to provide an effective simple method for the settlement of pile group foundation. The additional stress is provided for calculating the settlement of pile groups. This method is verified by the engineering examples. By comparing the Boussinesq method for deep foundation and the equivalent method, the calculated settlements are close to the measured ones at completion of settlement.