摘要
在超大跨地下洞室开挖时,经常会产生掌子面坍塌和支护结构失稳的现象。为安全快速地完成洞室开挖,使得洞室支护结构尽早封闭成环,依托某大型地下空间项目,提出了3种超大跨地下洞室开挖工法,通过采用数值模拟和监控量测相结合的方法分别对3种工法施工时洞室的受力变形情况进行了对比分析。结果表明:条形垂直分块开挖最大沉降位置始终位于拱顶,顶部最大沉降值为4 mm;除环形开挖外,条形开挖和条形垂直分块开挖穹顶最大拉应力分别为1.7 MPa和0.8 MPa,均满足钢纤维混凝土的抗拉要求;3种开挖工法下最小主应力的最大值均发生在穹顶边墙交界位置;条形垂直分块开挖工法在理论上对围岩扰动最小,穹顶沉降变形最小,穹顶受力较安全。
During the excavation of super-span underground caverns,the collapse of the tunnel face and the instability of the supporting structure often occur.In order to complete the excavation of the caverns safely and quickly,so that the supporting structure of the cavern can be closed as soon as possible,based on an actual underground space project,three excavation methods are proposed in this paper.By means of numerical simulation and monitoring measurement,the stress and deformation of the cavern during the construction by the three methods are compared and studied.The results show that the maximum settlement position under the strip and vertical block excavation method is always located at the vault,and the maximum settlement value at the top is 4 mm.Except for the circular excavation method,the maximum tensile stress of the dome under the strip excavation method as well as the strip and vertical block excavation method is 1.7 MPa and 0.8 MPa respectively,which meet the tensile requirements of steel fiber reinforced concrete.The maximum value of the minimum principal stress under the three excavation methods occurs at the junction of the dome and sidewall;the strip and vertical block excavation method has the smallest disturbance to the surrounding rock in theory,with the smallest settlement deformation and the safer stress condition of the dome.
作者
王帅帅
郭亚斌
王星
高轩
WANG Shuaishuai;GUO Yabin;WANG Xing;GAO Xuan(CCCC Second Highway Engineering Bureau Co.,Ltd.,Xi′an 710065;Engineering Design&Research Institute,CCCC Second Highway Engineering Bureau Co.,Ltd.,Xi′an 710100;CCCC Mountain Long Bridge Tunnel Construction Technology R&D Center,Xi′an 710100)
出处
《现代隧道技术》
CSCD
北大核心
2022年第S01期993-1003,共11页
Modern Tunnelling Technology
基金
中交第二公路工程局有限公司重点研发项目(2021X-4-17)
关键词
地下洞室
支护结构
数值模拟
开挖工法
穹顶
Underground cavern
Supporting structure
Numerical simulation
Excavation method
Dome
作者简介
王帅帅(1988-),男,博士,高级工程师,主要从隧道与地下工程领域的施工及管理工作,E-mail:8366wangshuai@sina.com;通讯作者:郭亚斌(1994-),男,硕士,工程师,主要从事隧道与地下工程领域的设计及研发工作,E-mail:2461226516@qq.com
