考虑桩桩相互作用的双排支护桩受力变形分析  

Analysis of forced deformation of double row support piles considering pile interaction

作　　者：张玲[1] 朱幸仁 欧强 ZHANG Ling;ZHU Xingren;OU Qiang(Institute of Geotechnical Engineering,Hunan University,Changsha,Hunan410082,China)

机构地区：[1]湖南大学岩土工程研究所

出　　处：《水文地质工程地质》2019年第5期72-80,共9页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金项目资助(51678231)

摘　　要：双排桩支护结构的变形与内力计算是其设计计算的重要内容之一。双排支护桩结构是由前排桩、后排桩及桩顶连系梁组成的空间门架式结构。在承受水平荷载时,后排桩向坑内发生挠曲变形,挤压桩间土体,同时桩间土体又对前排桩产生推力,使得前排桩向坑内发生挠曲变形,挤压前排桩桩前土体,以致该支护结构在传递水平荷载时,前后排桩及桩间土体之间存在非常复杂的相互作用。本文基于上述双排桩支护结构受力变形特性,将前、后排桩均视为竖向放置的弹性地基梁,以欧拉伯努利双层梁理论考虑前后排桩的相互作用,以水平向弹簧模拟桩间土相互作用,以朗肯土压力计算作用于后排桩的主动土压力,以弹性抗力法计算作用于前排桩基坑底面以下的被动土压力,以基坑底面为界人为将前、后排桩分为上下部分,并通过桩身各段的受力平衡建立前后排桩的挠曲变形控制微分方程,然后通过桩端约束及基坑坑底平面处的连续条件得到方程的解析解,给出了一种考虑桩桩相互作用以及桩土相互作用的双排桩支护结构计算方法。最后结合两个实例,将本文方法计算结果与实例结果进行对比分析,验证本文方法的可行性,以期为双排桩支护结构在工程中的设计计算提供借鉴。Calculation of deformation and internal force is one of the important contents of the double-row pile retaining structure.The double-row support pile structure is a space gantry structure composed of front row piles,rear row piles and pile top tie beams.When subjected to horizontal loads,flexural deflection to the pit occurs in the rear pile and the soil between the piles is squeezed.At the same time,the soil between the piles generates thrust to the front pile,so that flexural deflection to the pit also occurs in the front pile.The soil before the front piles is extruded,when the supporting structure transmits horizontal loads,there is a very complicated interaction between the front and rear piles and the soil between the piles.Based on the above-mentioned forced deformation characteristics of double-row pile retaining structure,the front and rear piles are regarded as vertical elastic foundation beams.The interaction of front and rear piles is considered by using the Euler-Bernoulli double-layer beam theory.The soil interaction between the piles is simulated through the horizontal spring,and the active earth pressure acting on the rear piles is calculated by the Rankine soil pressure.The passive earth pressure acting on the front pile below the bottom surface of foundation pit is calculated by using the elastic resistance method.From the bottom of the foundation pit,the double-row piles can be divided into upper and lower parts,the differential equations of the deflection deformation of the front and rear piles for each element are established by the force balance of the piles.The pile end constraints and the continuous conditions at the bottom of the foundation pit are introduced to obtain the analytical solution of the equation.A calculation method for the double-row pile retaining structure considering the pile interaction and the interaction between pile and soil is given in this study.By combining two examples,the calculation results of this method are compared with the reported results to verify the feas

关 键 词：双排桩支护结构 桩桩相互作用 桩土相互作用 地基反力系数 双层地基梁模型 弹性抗力法 

分 类 号：TU473.1[建筑科学—结构工程]