摘要
为探明刚性挡墙绕顶部转动(RT)模式下有限土体非极限状态土压力的变化规律,解决既有土压力计算方法中墙体位移、水平剪切应力等影响因素考虑不全的难题,基于微分单元法框架,建立了一种能综合考虑墙体位移、土体强度参数(c_(m)-φ_(m))、土拱效应和水平剪切应力影响的有限土体被动土压力数值计算方法。结合三轴卸荷试验与应力Mohr圆获取非极限状态下土体强度参数(c_(m)-φ_(m))与墙体位移的关系,依据土拱效应原理对有限土体进行应力分析,依据水平与竖直方向的静力平衡方程构建沿深度方向的被动土压力数值迭代算法。通过与已有研究对比验证了所提方法的合理性与准确性。结果表明:RT模式下有限土体受到的侧向约束作用有助于进一步发挥土体的抗剪强度;有限土体被动土压力沿深度方向呈非线性分布,土压力大小会随着土体强度参数(c_(m)-φ_(m))、初始滑裂面倾角、墙底位移比的减小以及宽深比的增大而降低。本文方法可为实际工程中挡土结构经济性设计提供理论指导。
To elucidate the variations in non-limit state earth pressure for limited soils mass under the rotation at the top of a rigid retaining wall(RT)mode,and to address the incomplete consideration of wall displacement,horizontal shear stress,and other influencing factors in existing earth pressure calculation methods,a numerical calculation method for passive earth pressure of a finite soil mass was developed within the framework of the differential element method.This method integrates considerations of wall displacement,soil strength parameters(c_(m)-φ_(m)),soil arching effects,and the impact of horizontal shear stress.By combining triaxial unloading tests and stress Mohr circles,the relationship between soil strength parameters(c_(m)-φ_(m))under non-limit states and wall displacement was derived.Based on the principles of soil arching effect,stress analysis of the finite soil body was conducted,and static equilibrium equations for differential soil elements were established,further creating a numerical iterative format for passive earth pressure within a depth range.The proposed method was validated for its rationality and accuracy through comparisons with existing research.The results show that the lateral constraints under the RT mode help enhance the soil's shear resistance;Non-linear distribution of passive earth pressures along depth in finite soils;the magnitude of earth pressure decreases with a reduction in soil strength parameters(c_(m)-φ_(m)),a decrease in the initial slip surface angle,a reduction in the bottom of wall displacement ratio,and an increase in the width-to-depth ratio.The method of this paper can provide theoretical guidance for the economic design of retaining structures in practical engineering.
作者
陕耀
董雅丞
吴遥杰
陈志宁
姚西平
Shan Yao;Dong Yacheng;Wu Yaojie;Chen Zhining;Yao Xiping(Key Laboratory of Road and Traffic Engineering of the Ministry of Education,Tongji University,Shanghai 201804,P.R.China;Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety,Shanghai 201804,P.R.China;Nanjing Metro Construction Co.,Ltd.,Nanjing 210017,P.R.China;Jiangsu Railway Group Co.,Ltd.,Nanjing 210012,P.R.China;Jiangsu Province Engineering Research Center of Intelligent and Green Railway,Nanjing 210012,P.R.China)
出处
《地下空间与工程学报》
北大核心
2025年第6期1888-1898,共11页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(52378458)。
关键词
有限土体
非极限状态
被动土压力
微分单元法
土拱效应
limited soils
non-limit state
passive earth pressure
differential element method
soil arching effect
