斜坡挡土桩的受力计算问题  

Problem of Force Calculation of Slope Retaining Piles

作　　者：杨光华[1,2,3] 孙树楷 贾恺 王东英 刘清华 YANG Guanghua;SUN Shukai;JIA Kai;WANG Dongying;LIU Qinghua(Guangdong Research Institute of Water Resources and Hydropower, Guangzhou 510635,China;The Geotechnical Engineering Technology Center of Guangdong Province, Guangzhou 510635,China;School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640,China)

机构地区：[1]广东省水利水电科学研究院,广州510635 [2]广东省岩土工程技术研究中心,广州510635 [3]华南理工大学土木与交通学院,广州510640

出　　处：《广东水利水电》2021年第12期1-9,共9页Guangdong Water Resources and Hydropower

基　　金：国家自然科学基金项目(编号:51778152,52078143)。

摘　　要：挡土桩在边坡垂直开挖工况下能起到很好的支护效果,但不同规范得到的挡土桩受力结果却不一致,有时甚至相差很大。因此,该文提出以反力平衡法计算滑坡推力,即在滑块的受力体系中加入桩的反作用力,并以加固后安全系数达到1.0作为平衡标准计算反力值。研究发现:均质平坡工况下,反力平衡法与朗肯、库仑理论一致,传递系数法偏小;均质斜坡工况下,基坑简化法只在斜坡高度较小时适用;非均质斜坡工况下,基坑简化法计算结果可能存在较大误差,以库仑破坏面或圆弧滑动面进行平衡分析也可能因与实际滑面不一致导致结果误差很大,而采用反力平衡法或传递系数法可验算各种可能破坏面并确定最大滑坡推力。通过以上3种不同工况证明反力平衡法具有普适性,可为不同边坡类型的挡土桩受力计算提供一种统一的解决方法。Retaining piles can play a very good supporting effect under the condition of vertical excavation of the slope,but the stress results of the retaining piles obtained by different specifications are inconsistent,and sometimes even vary greatly.Therefore,this paper proposes to use the reaction force balance method to calculate the landslide thrust,that is,the reaction force of the pile is added to the force system of the slider,and the reaction force value is calculated with the safety factor reaching 1.0 after reinforcement as the balance standard.The study found that:Under homogeneous flat slope conditions,the reaction force balance method is consistent with the limit equilibrium Rankine and Coulomb theory,and the transfer coefficient method is too small;Under homogeneous slope working conditions,the simplified method of foundation pit is only applicable when the slope height is small;In the case of non-homogeneous slopes,there may be large errors in the calculation results of the simplified method of foundation pits,and the balance analysis using the Coulomb failure surface or the arc sliding surface may also result in a large error due to inconsistency with the actual sliding surface.The reaction force balance method or the transfer coefficient method can be used to check various possible failure surfaces and determine the maximum landslide thrust.The above three different working conditions prove that the reaction force balance method has universal applicability,which can provide a unified solution for the calculation of the retaining piles of different slope types.

关 键 词：边坡开挖 挡土桩 基坑简化法 传递系数法 反力平衡法 

分 类 号：TU43[建筑科学—岩土工程] TV551.42[建筑科学—土工工程]