卸荷作用对超大断面隧道围岩压力的影响  

Effect of unloading on surrounding rock pressure of super large-section tunnel

作　　者：曹智淋 谢强[1] 宋战平[2,3] 王军保 CAO Zhilin;XIE Qiang;SONG Zhanping;WANG Junbao(School of Civil Engineering,Chongqing University,Chongqing 400045,China;School of Civil Engineering,Xi'an University of Architecture and Technology,Xi′an,Shaanxi 710055,China;Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering,Xi′an,Shaanxi 710055,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]西安建筑科技大学土木工程学院,陕西西安710055 [3]陕西省岩土与地下空间工程重点实验室,陕西西安710055

出　　处：《岩石力学与工程学报》2020年第S01期2882-2891,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51578447);陕西省创新能力支撑计划–创新团队(2020TD–005);陕西省住房城乡建设科技计划项目(2019–K39)。

摘　　要：在超大断面隧道分步开挖过程中,围岩应力发生动态变化,每一步开挖对岩体的影响都不同。根据岩体卸荷力学理论,在隧道施工中围岩不同卸荷带和质量劣化程度不断变化,结合贵阳市地铁2号线观水路站超大断面暗挖车站的双侧壁导坑法施工,通过数值模拟与理论分析方法,研究卸荷作用对超大断面暗挖隧道各导洞压力拱深度的影响。引入卸荷作用影响系数,对现有的隧道过程荷载计算方法进行改进,并与现有隧道过程荷载计算方法、传统公路隧道设计规范推荐计算法进行对比分析。将改进的隧道过程荷载计算方法分析结果同观水路站超大断面暗挖车站基于现场位移监测数据围岩压力反分析计算结果进行对比分析,改进后的隧道过程荷载计算值与现场监测结果基本一致,表明改进后的计算方法有较高的准确度。During the excavation by steps of super large-section tunnel,the stress of surrounding rock changes correspondingly,and each step of excavation has different impacts on rock mass.Based on the theory of unloading rock mass mechanics,the different unloading zone and the quality deterioration of surrounding rock are constantly changing in tunnel construction.Combined with double side heading construction of a super large-section tunnel in Guanshui Road station of Guiyang Metro Line 2,the effect of unloading on the depth of pressure arch of super large-section tunnel was analyzed by numerical simulation and theoretical analysis.The unloading effect coefficient was introduced to improve the existing method for calculating the process load of tunnel,and the results were compared with those of the calculation method of process load of existing tunnel and the recommended calculation method of highway tunnel.Comparing with the back analysis and calculation results of surrounding rock pressure based on field displacement monitoring data,the calculation results of the improved method were basically consistent with that,and it shows the method had high accuracy.

关 键 词：隧道工程 超大断面 分步施工 卸荷作用 围岩压力 

分 类 号：U45[建筑科学—桥梁与隧道工程]