强度折减法在软土深基坑抗隆起分析中的应用研究  

Application of Strength Reduction Method in Analysis of Basal Stability for Deep Excavations in Soft Clay

作　　者：许建 崔孝凯 XU Jian;CUI Xiaokai(China Construction Southwest Survey and Design Institute Co.Ltd.,Chengdu 610052)

机构地区：[1]中国建筑西南勘察设计研究院有限公司,成都610052

出　　处：《土工基础》2021年第6期718-722,共5页Soil Engineering and Foundation

摘　　要：基于强度折减法,结合软土深基坑工程开挖实例,分析软土基坑的的开挖过程和支护体系的力学特征,研究基坑支护结构嵌固深度、抗剪强度变化对抗隆起失稳的影响,并将计算结果与Terzaghi地基承载力法与Prandtle地基承载力计算法相比较。研究成果表明:(1)随着支护结构插入比D/H的增加,基坑抗隆起失稳面也逐渐增加,但插入比对抗隆起稳定性系数的提高影响有限;(2)随着软土抗剪强度的降低,基坑抗隆起稳定性系数呈非线性减小;(3)基于Terzaghi与Prandtle模式的计算结果大于强度折减法,高估了软土的抗隆起稳定性。In this paper,the excavation process of a deep excavation supporting project in the soft soils was investigated by using the strength reduction method.The influence of the embedded depth and the shear strength change of the deep excavation supporting structure on the uplift instability is also studied.The analysis results are compared with the results from Terzaghi foundation bearing capacity and Prandtl foundation bearing capacity estimation methods.The results show that:(1)with the increase of the insertion ratio D/h of the supporting structure,the factor of safety against the uplift stability in deep excavation also increases gradually,but the improvement of the factor of safety of the against the uplift failure is limited;(2)with the decrease of the shear strength of the soft soil,the uplift stability factor of safety in the deep excavation decreases nonlinearly;(3)the analytical results based on Terzaghi and Prandtl models are larger than the results from the strength reduction method,which overestimates the uplift resistance against the soft soil stability.

关 键 词：强度折减法 深基坑 软土 基坑抗隆起 

分 类 号：TU473[建筑科学—结构工程]