考虑坡度效应的水平受荷桩应变楔计算方法  

A method for calculating laterally loaded pile using strain wedge model considering slope effect

作　　者：杨明辉[1] 冯超博 赵明华[1] 罗宏[1] YANG Ming-hui;FENG Chao-bo;ZHAO Ming-hua;LUO Hong(Colledge of Civil Engineering, Hunan University, Changsha, Hunan 410082, China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《岩土力学》2018年第4期1271-1280,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51278184;No.51678230);教育部新世纪优秀人才支持计划(No.NCET-13-194);湖南大学青年教师成长资助项目~~

摘　　要：由于坡度效应的存在,常规方法并不适用于斜坡上水平受荷桩的计算,首先开展了斜坡上基桩的横向加载破坏试验,以确定斜坡上基桩的破坏模式。在此基础上,沿坡体方向对破坏土楔体进行斜向单元划分,提出了考虑坡度效应的土体应变楔模型,对于其中的关键参数应变楔深度与应变楔土体应变采用迭代求解。迭代过程中,建立基桩横向受荷的桩-土相互作用方程并用有限杆单元法求解,当求解得到的桩身地面处位移与应变楔模型中地面处土体位移之差小于某一允许值时,得到的基桩的水平位移及内力即为最终解答。通过与试验测试数据的对比,验证了该方法的合理性。最后,将土体破坏深度与边坡斜率的比值定义为陡坡效应影响范围,并对其影响因素进行了对比分析。结果表明,陡坡效应的影响范围受土体强度参数及基桩尺寸等多因素影响,其随着桩径的增加而减小,且随土体强度的增强而减小。Because of the slope effect, conventional methods are not applicable to calculate the deformation of laterally loaded piles in the slope. The failure test of laterally loaded pile in slope is carried out to determine the failure mode. The soil wedge is divided into oblique elements along the direction of the slope. Strain wedge model considering the effect of slope is proposed. Key parameters, strain wedge depth and soil strain of strain wedge, are obtained by iteratively solving equations of pile-soil interaction using finite bar element method. When the difference between the ground displacement of the pile and the ground displacement of strain wedge model is less than a permissible value, the ground displacement and internal force of pile obtained through the finite bar element method are the final answer. By comparing the test data and results of the proposed method, the rationality of the proposed method is verified. Finally, the ratio of the depth of damaged soil and the slope is defined as the scope of slope effect, and the influence factors are compared and analyzed. Results show that, the scope of slope effect is related to the strength parameters of soil and the size of pile, it decreases with the increase of pile diameter and soil strength.

关 键 词：陡坡桩 应变楔 弹性地基梁 水平受荷桩 

分 类 号：TU443[建筑科学—岩土工程]