岩土成层地基钻孔刚架抗滑桩计算的有限差分法  

Investigation of Double-Row Drilled Anti-Sliding Piles Embedded in Multi-Layered Soils and Rocks Using Finite Difference Method

作　　者：张海洋 高乐[1,2] 宋绪国 郭帅杰 闫穆涵 ZHANG Haiyang;GAO Le;SONG Xuguo;GUO Shuaijie;YAN Muhan(China Railway Design Corporation,Tianjin 300308,China;National Engineering Research Center for Digital Construction and Evaluation Technology of Urban Rail Transit,Tianjin 300308,China;State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China)

机构地区：[1]中国铁路设计集团有限公司,天津300308 [2]城市轨道交通数字化建设与测评技术国家工程研究中心,天津300308 [3]水利工程仿真与安全国家重点实验室(天津大学),天津300072

出　　处：《铁道标准设计》2024年第9期75-81,112,共8页Railway Standard Design

基　　金：中国国家铁路集团有限公司科技开发计划项目(K2022G058,L2022G014);中国铁路设计集团有限公司科技开发重点课题(2021A241013)。

摘　　要：传统悬臂或锚拉式抗滑桩采用人工挖孔施工,施工效率低、工期长且安全风险问题尤为突出,目前正被严格限制使用并逐步淘汰,因此,在边坡治理工程中使用机械钻孔成桩替代人工挖孔工艺是未来的发展趋势。钻孔刚架式抗滑桩侧向刚度大、施工效率高、结构空间受力更加合理,更加符合城市轨道交通建设“小空间解决大高差”的理念。首先,考虑抗滑桩普遍存在于岩土成层地基的实际情况,以水平弹簧模拟前、后排桩与桩间土的荷载相互作用,根据Euler-Bernoulli梁理论及刚架桩受荷特点,以桩周线性土弹簧刚度反映不同地层的水平抗力差异,建立刚架桩挠曲平衡微分方程;然后,基于有限差分法结合桩顶、桩端共8个边界条件,编制Python有限差分迭代运算程序实现了前/后桩及桩间土的协同作用,以及对刚架桩内力与变形的求解;最后,依托深圳地铁某路堑高边坡钻孔刚架桩现场监测案例,对比发现,二者桩顶最大变形相差在10%以内,验证了所提方法对岩土成层地基中钻孔刚架抗滑桩的适用性,开发的有限差分迭代程序简单便捷,可直接应用于钻孔刚架式抗滑桩工程设计。Conventional cantilever or anchored anti-sliding piles constructed through manual excavation have disadvantages of inefficiency,long construction duration,and safety risks.As these methods are now increasingly restricted and phased out,mechanical drilling to replace manual excavation is emerging as the future trend in slope stabilization engineering.The use of drilled rigid frame anti-sliding piles,characterized by large lateral stiffness,high construction efficiency,and a more rational structural load distribution,aligns better with the concept of addressing large elevation differences within limited spaces in urban rail transit construction.Considering that the anti-sliding piles are commonly constructed in multi-layered geotechnical foundations,the study simulated the interaction between the front and rear piles and the soil between them using horizontal springs.The varying lateral resistance in different strata was represented by linear soil spring stiffness around the piles,and the differential bending balance equation for rigid frame piles was established based on the Euler-Bernoulli beam theory and their load characteristics.A Python-based finite difference iterative program was then developed,using finite difference and incorporating eight boundary conditions at the pile head and tip.This program enabled the simulation of the synergistic behavior of the front and rear piles with the soil in between,and the calculation of the internal forces and deformations of the rigid frame piles.A case study involving in-situ monitoring of drilled rigid frame piles at a high cut slope in Shenzhen metro project was conducted.The maximum deformation values at the pile top predicted by the program differed by less than 10%compared to the field data,validating the applicability of the proposed method for evaluating drilled rigid frame anti-sliding piles embedded in multi-layered geotechnical foundations.The developed finite difference iterative program is simple and convenient,and can be directly applied to the engineering

关 键 词：地铁 路堑 岩土成层 钻孔灌注桩 刚架式抗滑桩 有限差分 现场监测 

分 类 号：U213.1[交通运输工程—道路与铁道工程] U231U418.5