水平荷载作用下斜桩承载变形性状数值分析  

Numerical Analysis on Bearing and Deformation Behavior of Horizontally Loaded Batter Piles

作　　者：曹卫平[1] 樊文甫 CAO Wei-ping FAN Wen-fu(School of Civil Engineering, Xi＇an University of Architecture and Technology, Xi＇an 710055, Shaanxi, China TBEA Sunoasis Co., Ltd., Urumqi 830011, Xinjiang, China)

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055 [2]特变电工新疆新能源股份有限公司,新疆乌鲁木齐830011

出　　处：《中国公路学报》2017年第9期34-43,共10页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51078308);陕西省自然科学基础研究计划项目(2015JM5260)

摘　　要：为研究水平受荷斜桩的承载变形性状,采用有限元软件模拟了斜桩在水平荷载作用下的性状并与直桩进行了比较,分析了桩身倾角、桩顶竖向荷载对斜桩桩身水平位移、桩身弯矩及剪力的影响,研究了斜桩与桩侧土之间的挤压、剪切相互作用,对水平受荷斜桩有效桩长的影响因素进行了探讨。结果表明:正斜桩的水平承载力比直桩大,负斜桩的水平承载力比直桩小;桩身倾角对斜桩水平位移、桩身弯矩及剪力有较大的影响;正斜桩桩顶水平位移小于直桩,负斜桩桩顶水平位移大于直桩,桩身倾角越大,斜桩与直桩桩顶水平位移差异越大;正斜桩、负斜桩的桩身弯矩均小于直桩,桩身倾角越大,正斜桩桩身弯矩越小,负斜桩桩身弯矩越大;正斜桩及负斜桩桩身剪力均小于直桩,正斜桩桩身剪力小于负斜桩桩身剪力;桩顶竖向荷载对正斜桩、负斜桩水平承载力的影响不同,竖向荷载提高了负斜桩的水平承载力,削弱了正斜桩的水平承载力;水平受荷斜桩与桩侧土之间的相互作用以挤压为主,剪切作用较弱;水平受荷斜桩存在一个有效桩长,对于相同的土层,无论是正斜桩、负斜桩,其有效桩长基本相同;桩侧上部土体剪切模量增大对减小有效桩长有显著的影响,下部土体剪切模量变化对有效桩长影响不大。To investigate the bearing and deformation behavior of horizontally loaded batter piles, the finite element method （FEM） was utilized to simulate the performance of batter piles under the horizontal load, whilst horizontal batter piles were compared with vertical piles. The influence of pile shaft inclined angle and vertical load on the horizontal displacement, bending moment and shear force of batter pile was investigated. With the exploration of the extrusion and shear interaction between the pile and the surrounding soil, factors influencing the effective length of batter pile under horizontal load were discussed. The results show that the horizontal bearing capacity of the vertical pile is less than that of the positive batter pile, but greater than that of the negative batter pile. The horizontal displacement, bending moment and shear force of batter piles are significantly influenced by the pile shaft inclined angle. The horizontal displacement of the vertical piles is greater than that of the positive batter piles, but less than that of the negative batter piles. The bigger the shaft inclined angle is, the greater the difference of the horizontal displacement between the vertical and the batter piles can be. The bending moment of the batter piles, whether positive or negative, is less than that of the vertical piles. And the bigger the inclined angles are, the smaller the bending moment is for the positive batter piles, but the greater the bending moment is for the negative batter piles. Compared with vertical counterparts, both two types of batter pile have smaller shear force than vertical piles, and the shear force of positive batter piles is smaller than that of the negative batter piles. It is apparent that the vertical load acting on pile head has different impact on the horizontal bearing capacity of the positive and the negative batter piles. The application of the vertical load can increase the horizontal bearing capacity of the positive batter piles while decrease the capacity of the negative

关 键 词：道路工程 斜桩 数值分析 水平承载力 桩身倾角 

分 类 号：U416.1[交通运输工程—道路与铁道工程]