基于上限理论的预留土支护基坑极限抗力分析  

Passive earth pressure analysis of berm-retained excavation by upper bound method

作　　者：秦会来 周予启 黄茂松[2] 周同和 QIN Hui-lai;ZHOU Yu-qi;HUANG Mao-song;ZHOU Tong-he(China Construction First Group Construction&Development Co.,Ltd.,Beijing 100102,China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Comprehensive Design Institute,Zhengzhou University,Zhengzhou 450002,China)

机构地区：[1]中建一局集团建设发展有限公司,北京100102 [2]同济大学地下建筑与工程系,上海200092 [3]郑州大学综合设计研究院有限公司,河南郑州450002

出　　处：《岩土工程学报》2020年第6期1101-1107,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金重点项目(51738010)。

摘　　要：预留土支护基坑被动区的抗力大小与分布是预留土支护基坑分析设计的基础,但目前还没找到预留土支护基坑被动区抗力计算的合理方法。根据预留土支护的特点,基于极限分析上限理论,运用竖向条块对预留土支护基坑被动区进行离散,并构建相容速度场,从而提出了预留土支护基坑被动区极限抗力的上限解法。借助优化技术对相容速度场的优化分析获得了预留土支护基坑被动区抗力的最优上限解。为检验所提出上限解法的合理性,对不同挡墙高度、地质参数等条件下的被动土压力进行了计算,并与经典朗肯理论解的土压力值以及破坏面进行对比。应用所提出的预留土支护基坑被动区抗力上限方法,对不同预留土顶部宽度、预留土底部宽度、预留土高度以及预留土边坡坡度系数等参数条件下的被动区极限抗力值、极限抗力沿深度的分布以及破坏面进行了计算分析,讨论了这些参数对预留土支护基坑被动区抗力以及破坏面的影响规律。所提方法为今后预留土支护基坑的设计以及优化设计奠定了基础。The passive earth pressure should be known for the design of the berm-retained excavation,but no reasonable method for calculating the passive earth pressure has been found until now.According to the characteristics of the berm-retained excavation,the upper bound method based on the limit analysis theory is used to analyze the passive earth pressure provided by the passive soil area.To use the upper bound method,the vertical slice blocks are used to separate the passive soil area of the berm-retained excavation,and a compatible speed field is constructed.The optimization analysis technology is used to obtain the minimum upper bound solution.In order to test the rationality of the proposed upper bound solution,the passive earth pressures with different wall heights,geological parameters and other conditions are calculated by the proposed upper bound method,and the values and failure envelops are compared with the classical Rankine’s solutions.By employing the proposed upper bound method,the value of the passive earth pressure,the distribution of the passive earth pressure along the retaining wall,the failure envelops of passive soil area are studied under different parameters such as the berm top width,berm bottom width,berm height and berm slope coefficient.The influences of these parameters on the passive earth pressure and the failure envelops are discussed.The proposed method may lay the foundation for the design and optimization design of the berm-retained excavation in the future.

关 键 词：极限分析 上限解 预留土 基坑支护 被动土压力 

分 类 号：TU43[建筑科学—岩土工程]