基于有限差分法的填土边坡复合结构受力特征分析  

Stress Analysis of Filling Slope Composite Structure Based on the Finite Difference Method

作　　者：李漪 柴平稳 李珂 贺修安 王红伟 LI Yi;CHAI Ping-wen;LI Ke;HE Xiu-an;WANG Hong-wei(Power China Hubei Electric Engineering Corporation Limited,Wuhan 430040,China;State Grid Economic and Technological Research Institute Co.,Ltd.,Beijing 102209,China;Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]湖北省电力勘测设计院有限公司,武汉430040 [2]国网经济技术研究院有限公司,北京102209 [3]中国地质大学(武汉)工程学院,武汉430074

出　　处：《科学技术与工程》2023年第20期8570-8578,共9页Science Technology and Engineering

基　　金：湖北省电力勘测设计院有限公司科研项目(K2021-1-01)。

摘　　要：桩基托梁挡土墙结构可以有效提高地基承载力,在软土地基边坡防治中具有很好的实用价值。现有的理论计算采用传统连续梁模型对托梁或桩基受力特征进行求解,其计算模型相对理想化,未考虑地基与梁或桩之间的协调变形,容易出现误差。为此,首先基于挡土墙墙后土压力静力平衡条件,求解得到墙后土压力荷载,并作为托梁及桩基的输入荷载,然后基于有限差分原理,将托梁视为Winkler地基上的梁理论,提出托梁内力的有限差分解法,进一步考虑桩基地基系数随深度变化的特征,即m法,采用有限差分法求解桩基受力特征,然后将理论应用于工程实例,将所提出的求解方法和传统计算方法进行对比。结果表明:传统连续梁模型理论忽略了土体抗力,过小的评价了结构的承载力,而所提出的弹性地基梁求解办法更能反映实际工程情况,其计算结果可靠性更高;如果前后排桩按照一定比例承受不同的荷载,得到后排桩位移、弯矩和剪力随荷载的增大而增大,研究成果可为工程防护边坡提供理论依据。The bearing capacity of the foundation can be significantly increased by using a pile joist retaining wall structure,which also has strong practical value for treating soft soil foundations and preventing slopes.The classic continuous beam model,which is relatively ideal and prone to mistakes,is utilized in the current theoretical calculation to solve the stress characteristics of joist or piling foundation.Based on the static balance condition of the earth pressure behind the retaining wall,the earth pressure load behind the wall was solved and used as the input load of the joist and pile foundation.Then,based on the finite difference principle,the supporting beam was regarded as the beam theory on the Winkler foundation,and the finite difference method of the internal force of the supporting beam was proposed.Further considering the characteristics of the foundation coefficient of the pile foundation changing with depth,that is,the m method,the finite difference method was used to solve the stress characteristics of the pile foundation.Then the proposed solution method was compared with the traditional calculation method.The results show that the traditional model of continuous beam theory ignores the soil resistance,it s too small to evaluate the bearing capacity of the structure,the proposed elastic foundation beam solution method can better reflect the actual engineering situation,and its calculation results are more reliable.If the double-row piles bear different loads according to a certain proportion,the displacement,bending moment and shear force of the rear-row piles will increase with the increase of the load.The research results can provide a theoretical basis for engineering slope protection.

关 键 词：边坡 挡土墙 托梁 桩基 有限差分法 

分 类 号：P642.23[天文地球—工程地质学]