摘要
基于平面弹性地基梁法,采用结构力学矩阵分析法,进一步完善已往工作推导公式解答的缺陷。传统的平面桩支撑解答计算理论局限于计算支护面桩体的内力和变形,没有解决xoy水平面支撑轴力计算问题,但真三维解答推导过于复杂,通常三维模型计算依托有限元软件。与传统二维排桩支护模型相比,在以往的工作基础上,推导出考虑开挖过程、桩-土-冠梁-支撑共同作用的支护面位移、受力矩阵解答方程组和xoy水平面计算支撑轴力计算方法,并利用FORTRAN语言编制的程序求解。依托工程实践项目分析冠梁、腰梁、支护桩、支撑位移和内力在空间效应下的变化规律并与有限元法、理正深基坑计算结果及经非线性回归处理监测数据对比分析,结果表明,考虑开挖过程、桩-土-冠梁-支撑共同作用矩阵分析法计算出的冠梁位移具有明显的空间效应,靠近基坑角部更明显,距离坑角约1/4冠梁跨度内可以适当增加桩间距,xoy水平面坑角支撑轴力明显较中部小,与监测值能较好吻合,支撑截面和配筋计算可以针对性的优化,从而降低工程造价。冠梁、桩身位移与理正深基坑、监测数据能较好地吻合,再次验证方法的合理性与可行性,可以作为一种优化设计新方法。
The traditional theory for plane pile support computation is limited to calculating the internal forces and deformations of the pile body on the supporting plane.It does not address the calculation of axial forces on the xoy horizontal plane support.Deriving a true three-dimensional solution is overly complex,often necessitating reliance on finite element software for three-dimensional model calculations.This study builds upon prior research to derive displacement and force matrix solution equations for the support surface,accounting for excavation processes,pile-soil-crown beam-support structure interactions,and the calculation method of axial forces on the xoy horizontal plane.These equations are solved using a FORTRAN program.Based on an engineering project,this study analyzes and compares the behavior of crown beams,waist beams,support piles,support displacements,and internal forces under spatial effects with the finite element method,LiZheng’s deep foundation pit calculation results,and monitoring data processed through nonlinear regression.The results indicate that the crown beam displacement,calculated using a matrix analysis method that accounts for the excavation process and pile-soil-crown beam-support structure interaction,exhibits a pronounced spatial effect.This effect is most prominent near the corner of the foundation pit.Within approximately one-fourth of the distance from the pit angle along the span of the crown beam,the pile spacing can be increased appropriately.The axial force on the support at the xoy horizontal pit angle is significantly lower than that at the center,aligning well with the monitoring data.Targeted optimization of the support section and reinforcement calculations can lead to reduced engineering costs.The displacement of the crown beam and pile body aligns well with the monitoring data and the results computed by LiZheng software,further validating the method’s rationality and feasibility.This can serve as a novel optimization design approach.
作者
肖荣军
马威
李锋
袁丽云
XIAO Rong-jun;MA Wei;LI Feng;YUAN Li-yun(Guangdong Foshan Geology Bureau,Foshan,Guangdong 528000,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2024年第S01期579-595,共17页
Rock and Soil Mechanics
关键词
深基坑
排桩支护
矩阵分析法
内力与变形
支撑轴力
deep foundation pit
row pile support
matrix analysis method
internal force and deformation
supporting axial force
