节理软弱围岩中浅埋大跨双线隧道最小安全净距研究  

Study on Minimum Safe Net Distance Between Small-space Tunnels in Jointed Weak Rocks with Shallow Depths and Large Spans

作　　者：史佩杰 杨绍战[2] 杨硕 郭宏伟 戈若愚 SHI Peijie;YANG Shaozhan;YANG Shuo;GUO Hongwei;GE Ruoyu(CCDI(Suzhou)Exploration&Design Consulting Co.,Ltd,Suzhou 215123,China;CCCC First Highway Consultants Co.,Ltd,Xi’an 710075,China;High-tech District(Huqiu District)Urban Construction Management Service Center,Suzhou 215163,China)

机构地区：[1]悉地(苏州)勘察设计顾问有限公司,苏州215123 [2]中交第一公路勘察设计研究院有限公司,西安710075 [3]苏州高新区(虎丘区)城市建设管理服务中心,苏州215163

出　　处：《交通与运输》2022年第2期28-33,共6页Traffic & Transportation

摘　　要：小净距隧道因其地形适应性强、线路灵活而得以大量应用。最小安全净距是控制小净距隧道线路设计的关键指标,也是影响隧洞施工安全的主要因素之一。依托苏州高新区某浅埋大跨小净距隧道工程,采用平面应变有限元法,考虑软弱节理围岩各向异性本构特征,分析净距大小对中夹岩塑性点分布、隧道和地层变形、支护结构内力的影响规律,提出最小安全净距的判定标准。结果表明,以塑性区是否贯通和支护结构承载能力、是否满足安全系数规定作为判别标准,该隧道工程的最小安全净距可取为0.4倍隧道开挖净宽;而以隧道和地层变形及支护结构内力随净距减小的非线性突增为判别标准,所得最小安全净距偏于保守。研究结果可为节理围岩地区小净距隧道的净距优化提供理论参考。Small-space tunnels are widely used nowadays because of their high adaptability and flexibility in route design.The minimum safe net distance between tunnels is one of the key parameters to control the route design of small-space tunnels,and to affect the safety of tunnel construction.Based on the small-space tunnel project in the High-tech district in Suzhou,the plane strain finite element analysis method is used,considering the effect of jointed weak rock condition,to investigate the effects of minimum safe net distance on the distribution of plastic points in the middle rock,the deformation of tunnels and the ground surface,and the inner forces of the supporting structures,and to propose the design criterion for the minimum net safe distance.The results show that,based on the criterions of whether the plastic points penetrate the middle rock,and whether the bearing capacity can satisfy the safety factor requirement,a minimum net safe distance of 0.4 times the tunnel width can be obtained for the studied tunnel project.However,the results will be more conservative if only based on the nonlinear increases of tunnel and ground deformations,and the internal forces of supporting structures.The results can provide a reference for the optimization of small-space tunnels in weak jointed rock areas.

关 键 词：小净距隧道 最小安全净距 节理岩体 沉降 支护内力 

分 类 号：U491[交通运输工程—交通运输规划与管理]