\r程雪松^{1, 2}，李昕昊²，潘 军²，郑 刚\r^{1, 2}\r
\r
AuthorsHTML:\r程雪松^{1, 2}，李昕昊²，潘 军²，郑 刚\r^{1, 2}\r
\r
AuthorsListE:\rCheng Xuesong^{1, 2}， Li Xinhao²，Pan Jun²，Zheng Gang\r^{1, 2}\r
\r
AuthorsHTMLE:\rCheng Xuesong^{1, 2}， Li Xinhao²，Pan Jun²，Zheng Gang\r^{1, 2}\r
\r
Unit:\r1. 天津大学滨海土木工程结构与安全教育部重点实验室，天津 300072；
2. 天津大学建筑工程学院，天津 300072\r
\r
Unit_EngLish:\r1. Key Laboratory of Coastal Civil Structure and Safety of Minisry of Education ，Tianjin University，Tianjin 300072，China；
2. School of Civil Engineering，Tianjin University，Tianjin 300072，China\r
\r
Abstract_Chinese:\r基坑坑底隆起稳定验算是基坑设计最重要的问题之一，坑底隆起失稳破坏伴随着土体和围护结构失效．然而目前基坑稳定常用的分析方法，强度折减有限元法，在已有研究和实践中却仅折减土体强度，未对围护结构强度进行折减，这与强度折减法的计算理念不统一，且与实际基坑的破坏模式有一定差异．因此本文提出同时折减土体抗剪强度和围护结构抗弯强度的强度折减有限元法．进而通过建立大量的数值模型，对比了考虑与不考虑围护结构抗弯强度折减的计算结果，并与圆弧滑动法进行了对比分析．最后基于实际工程案例分析了新方法的应用效果．分析结果表明，不折减围护结构抗弯强度将高估基坑的坑底抗隆起稳定安全水平，验证了采用强度折减有限元法时同时折减土体强度和围护结构抗弯强度的必要性．\r
\r
Abstract_English:\rThe evaluation on the basal-heave stability of excavations is one of the most important problems in excavation design．The instability of the basal-heave of excavations is accompanied by failure of soil and the retaining structures．Finite element method(FEM)with shear strength reduction is one of the commonly used methods for calculating the basal-heave stability of excavations；however，this method only reduces the shear strength of soil and ignores the flexural strength of the retaining structures，which is not only inconsistent with the concept of the method，but also differs from the failure mode of practical evaluations．Therefore，an improved FEM that simultaneously reduces the shear strength of soil and the flexural strength of the retaining structures is proposed in this paper．By establishing a large number of numerical models，the calculation results of the improved FEM with strength reduction and the traditional FEM with strength reduction were compared，and they were also compared with the slip circle method. Finally，based on practical engineering cases，the application effect of the improved FEM with strength reduction was analyzed．The analysis results show that the safety level of the basal-heave of excavations will be over estimated if the flexural strength of the retaining structures is not reduced when FEMs with strength reduction are used．The necessity of simultaneously reducing the strength of the soil and the flexural strength of the retaining structures when using FEMs with strength reduction is demonstrated．\r
\r
Keyword_Chinese:基坑；坑底隆起稳定；围护结构强度；强度折减法\r

Keywords_English:excavations；basal-heave stability；strength of retaining structure；strength reduction method\r


PDF全文下载地址:http://xbzrb.tju.edu.cn/#/digest?ArticleID=6292