考虑松动区渐进破坏的隧道松动土压力研究  

Loose earth pressure of tunnels considering progressive failure of loosen zone

作　　者：耿哲 袁大军[1,2] 金大龙 舒计城[3] 娄瑞 GENG Zhe;YUAN Dajun;JIN Dalong;SHU Jicheng;LOU Rui(Key Laboratory of Urban Underground Engineering,Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;China Railway 14th Bureau Group Shield Engineering Co.,Ltd.,Nanjing 211800,China)

机构地区：[1]北京交通大学城市地下工程教育部重点实验室,北京100044 [2]北京交通大学土木建筑工程学院,北京100044 [3]中铁十四局集团大盾构工程有限公司,江苏南京211800

出　　处：《岩土工程学报》2023年第8期1754-1762,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金“联合基金项目”(U1834208)。

摘　　要：浅埋盾构隧道所受松动土压力与松动区的渐进破坏和土拱效应密切相关,基于椭球体理论建立了椭圆形松动区模型,提出了土体损失量与松动区高度之间的关系,探明了松动区渐进破坏的演化过程和极限状态。考虑土体黏聚力和松弛区椭圆形状,基于大主应力迹线法给出了滑移面任意倾角下的侧向土压力系数,推导并验证了隧道拱顶松动土压力的迭代计算方法,针对极限状态和非极限状态展开参数分析,研究结果表明:(1)拱顶松动土压力随土体内摩擦角和黏聚力的增加而减小;(2)随松动区高度的增加,拱顶松动土压力先急剧减小,然后逐渐增加,最终趋于稳定。The loose earth pressure of shallow shield tunnel is closely related to the soil arch effect and the progressive failure of the loosen zone.Based on the ellipsoidal theory,the elliptic loosen zone model is established,and the relationship between the ground loss and the loosen zone height is proposed.The process of progressive failure and the limit state are defined.Considering the soil cohesion and the ellipse shape of the loosen zone,the lateral earth pressure coefficient under arbitrary dip angle of slip surface is obtained by means of the large principal stress trace method.The formula for calculating the loose earth pressure at tunnel top is derived and verified.The parameter analysis is carried out for the limit state and non-limit state,and the research results show that:(1)The loose soil pressure at tunnel top decreases with the increase of the internal friction angle and cohesion.(2)With the increase of the loosen zone height,the loose earth pressure at tunnel top decreases sharply first,then increases gradually,and finally tends to be stable.

关 键 词：盾构隧道 渐进破坏 松动土压力 非极限状态 

分 类 号：TU432[建筑科学—岩土工程]