融化作用下多年冻土隧道围岩的弹塑性解及其与支护的相互作用分析  

Elastoplastic analysis of surrounding rock of permafrost tunnel with thawing effect and its interaction with support

作　　者：夏才初[1,2,3] 黄继辉[2,3] 卞跃威[2,3] 唐志成[2,3] 

机构地区：[1]三峡大学土木与建筑学院,湖北宜昌443002 [2]同济大学地下建筑与工程系,上海200092 [3]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土力学》2013年第7期1987-1994,共8页Rock and Soil Mechanics

基　　金：西部交通建设科技项目(No.20113184901070);西部交通建设科技项目(No.2011318799740)

摘　　要：多年冻土隧道修建中,施工活动产生的热量将导致多年冻土围岩中出现一定范围的融化圈,进而影响支护的受力以及隧道洞室的收敛。将围岩分为融化区和未融化区,将融化区围岩视为弹塑性介质,未融化区围岩视为弹性介质,建立并求解融化作用下多年冻土隧道围岩弹塑性模型,对不同的围岩条件及支护工况下多年冻土段隧道施工中围岩与支护的相互作用进行分析。结果表明,该模型表现了融化作用下多年冻土围岩与支护相互作用的特征;在较差围岩中,喷射混凝土支护的强度是控制融化作用下多年冻土围岩稳定以及隧道周边位移量的关键因素。在多年冻土隧道施工中,可采用本模型确定施工中容许的最大围岩融化深度,施工中应采取有效措施避免围岩中出现过大的融化圈。During the construction of permafrost tunnels,some extent of surrounding rock will thaw under the effect of construction behavior;it will affect the pressure on support and the convergence of tunnel.An elastoplastic model of surrounding rock of permafrost tunnel under thawing effect is built;and the elastoplastic solution of the model is deduced.In the model,the surrounding rock is divided into frozen zone and thawed zone,considering the frozen zone rock mass as elastic material and the thawed zone rock mass as elastoplastic material.Interaction between the surrounding rock and the support is analyzed under different kinds of surrounding rock and support conditions.The results indicate that the model can represent the characteristics of the interaction between permafrost rock mass and support under thawing effect;and the strength of shotcrete plays an important role in maintaining the stability of permafrost rock mass and controlling the deformation of permafrost tunnel under thawing effect.This model can be used to identify the maximum allowable thawing depth of surrounding rock during construction of permafrost tunnels.Some measures should be taken to control the thawed zone during construction of permafrost tunnels.

关 键 词：多年冻土隧道 融化作用 围岩与支护相互作用 收敛约束法 

分 类 号：U45[建筑科学—桥梁与隧道工程]