桩-土相互作用支护桩受力变形计算方法

为研究桩-土非线性相互作用对深基坑支护结构内力与位移的影响,提出了一种桩-土相互作用支护桩受力变形计算的方法.该方法将基坑开挖面以上的桩体视为有限数量的弹性体,开挖面以下的桩体视为Winker地基梁,支撑结构为二力杆弹簧,并考虑支护桩和内支撑的变形协调,基于桩结构分段分坐标法和弹性地基梁法,推导出了考虑桩-土-内支撑共同作用的支护桩体挠曲微分方程.结合理论土压力,采用该方程计算获得了不同开挖深度的桩体水平位移和桩体弯矩,并与规范法、实测值进行比较.结果表明:本文方法计算得到的支护桩最大水平位移比规范法小15.2%,最大弯矩较规范法小26.6%,均与实测值更为相近. 

A Novel Method for Calculating Stress and Deformation of Supporting Pile Considering Pile-Soil Interaction

To study the pile-soil interaction on the internal force and deformation, a novel calculation method for calculating stress and deformation of supporting pile considering pile-soil interaction was proposed. This method treats the pile body above the excavation surface as a finite number of elastomers, the section below the excavation surface as Winker elastic foundation beam, and support structure as two-force elastic rod. The deformation compatibility between supporting pile and inner supporting system is also considered. Based on segmentation coordinate system and elastic beam-on-foundation system, the differential equation of pile deflection considering soil-pile-internal bracing interaction was proposed. By using this method and theoretical values of soil pressure, the lateral displacement and bending moment of supporting pile at different excavation depths were obtained and compared with the standard values and measured values. The results show that the calculated maximum lateral displacement of the supporting pile is 15.2% smaller than that of the standard method, and the calculated maximum bending moment is 26.2% smaller than that of the standard method, both of which are more close to the measured values.