岩土力学2024，Vol.45Issue(3)：797-808,12.DOI:10.16285/j.rsm.2023.0372
基于被动区土弹簧刚度降低过程的基坑围护结构计算增量法及软化p-y曲线
Incremental calculation method of foundation pit enclosure structure and softening p-y curves based on stiffness reduction process of the soil springs in the passive zone
摘要
Abstract
The incremental method based on the beam finite element method is commonly used for calculating foundation pit enclosure structures.However,there is a lack of research on the dynamic decrease of soil spring stiffness in the passive zone during excavation,which leads to soil resistance softening.This paper introduces two stiffness variation coefficients to quantify the dynamic change of soil spring parameters in the passive zone and establishes an incremental method for calculating foundation pit enclosure structures based on this process.For nonlinear foundation models,a refined incremental method is proposed for numerical calculations.Three basic soil spring models(linear elastic,ideal elastic-perfectly plastic,and hyperbolic)are used to obtain the softening p-y curves in the passive zone.A comparison of these models shows that the variation curve of the equivalent horizontal resistance coefficient obtained using the hyperbolic soil spring model aligns better with actual observations.An engineering example demonstrates that the calculation results based on the hyperbolic soil spring model correspond better to measured wall displacements at different excavation stages.Parameter analysis highlights the significant influence of the stiffness variation coefficient related to the ultimate resistance pu of the soil in the passive zone.Therefore,when using the proposed method,careful attention should be given to calculating the ultimate resistance pu and the influence of excavation on it in the passive area should be considered.关键词
基坑围护结构/增量法/基坑被动区/非线性土弹簧/软化p-y曲线Key words
foundation pit enclosure structure/incremental method/foundation pit passive zone/nonlinear soil spring/softening p-y curve分类
建筑与水利引用本文复制引用
雷国平,苏栋,程马遥,刘慧芬,张维..基于被动区土弹簧刚度降低过程的基坑围护结构计算增量法及软化p-y曲线[J].岩土力学,2024,45(3):797-808,12.基金项目
国家自然科学基金面上项目(No.51878416) （No.51878416）
广东省自然科学基金面上项目(No.2023A1515011772) （No.2023A1515011772）
佛山市教育局高校教师创新项目(No.2021XJZZ10) （No.2021XJZZ10）
深圳市自然科学基金(No.JCYJ20210324094607020).This work was supported by the National Natural Science Foundation of China(51878416),the Guangdong Natural Science Foundation(2023A1515011772),the Characteristic Innovation of University Teachers from Foshan Education Bureau(2021XJZZ10)and the Natural Science Foundation of Shenzhen(JCYJ20210324094607020). （No.JCYJ20210324094607020）
