超大断面隧道工法转换过渡段最优长度  

Optimal Length of Transition Section in Super-large Cross-section Tunnel

作　　者：殷明伦 张晋勋 江玉生[2] 江华[2] 王春河 YIN Ming-lun;ZHANG Jin-xun;JIANG Yu-sheng;JIANG Hua;WANG Chun-he(Postdoctoral Program,Beijing Urban Construction Group Co.,Ltd.,Beijing 100088,China;School of Mechanics and Civil Engineering,China University of Mining&Technology,Beijing 100083,China;China State Construction Shandong Investment Co.,Ltd.,Jinan 250101,China)

机构地区：[1]北京城建集团博士后工作站,北京100088 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083 [3]中建山东投资有限公司,济南250101

出　　处：《科学技术与工程》2021年第3期1163-1168,共6页Science Technology and Engineering

基　　金：国家自然科学基金重点项目(U1261212);北京市教委成果转化与产业化项目(ZDZH20141141301)。

摘　　要：隧道掘进过程中掌子面围岩状况不停变化,通常情况下针对不同围岩级别,采用不同的开挖工法,不同开挖方式对应的不同支护体系有着不同的受力模式,因此工法转换处围岩-支护体系复杂。以京沪高速济南连接线工程龙鼎隧道为背景,结合现场实测及数值模拟的方法研究施工方法由中隔墙(center diagram,CD)法施工转换为台阶法施工时结构内力及围岩应力状态的变化,研究最优的工法转换时机,确定工法转换过渡段最优长度,并在实际工程中验证。在工程所出现的围岩由Ⅳ_2级突变为Ⅲ_2级的情况下,超大断面隧道由CD法转换为台阶法设置10 m的过渡段是合理的。过渡段的设置有效减小了拱顶沉降,优化了支护与围岩受力状态,有利于围岩及支护结构稳定;并且可以最大程度保证工程进度。During the tunneling process,the rock state of the tunnel face is constantly changing.Under normal circumstances,different supporting modes and excavation methods are used for different grades of surrounding rock.So the surrounding rock-supporting system is complex during the transformation of excavation methods.In this research,the change of the structural internal force and the stress state of surrounding rock during the transformation from center diagram(CD)method to step method was carried out by combining the field measurement and numerical simulation with the background of the Longding tunnel in the Beijing-Shanghai high-speed railway project.Furthermore,the optimal length of transition section was studied to validate the results in actual engineering.The results show that it is reasonable to set 10 m transition section from CD method to step method in the case of the surrounding rock’s sudden change from GradeⅣ2 to GradeⅢ2,which effectively reduces the vault settlement and optimizes the support and the surrounding rock force state.It is conducive to the stability of the surrounding rock and support structure,and ensures the progress of the project.

关 键 词：超大断面隧道 工法转换 过渡段 数值模拟 现场监测 

分 类 号：U455.7[建筑科学—桥梁与隧道工程]