“先盾后扩”隧道穿越地裂缝带管片拼装方式及影响  

Segment Assembling Method and Impact on“ Shield Before Expansion”Construction Passing Through Ground Fissures

作　　者：高强 姚毅[2] 杨喜 GAO Qiang;YAO Yi;YANG Xi(Guangzhou Metro Design&Research Institute Co.Ltd.,Guangzhou 510010,China;School of Highway,Chang’an University,Xi’an 710064,China)

机构地区：[1]广州地铁设计研究院股份有限公司,广州510010 [2]长安大学公路学院,西安710064

出　　处：《铁道建筑》2023年第10期87-91,共5页Railway Engineering

基　　金：西安市轨道交通集团有限公司科技项目(D15-YJ-152021006);广州地铁设计研究院股份有限公司科技项目(KY-2020-003)。

摘　　要：依托西安地铁15号线府君庙村站—祝村站区间盾构隧道穿越地裂缝带工程,分析了“先盾后扩”法施工管片拼装方式及工程影响。基于理论分析推导了土层参数、断面椭圆度和地表最大沉降的关系式。结果表明:考虑设防段扩挖施工便利性和正常段结构受力稳定性,设防段管片宜采用通缝拼装并将封顶块置于拱顶正中央,正常段管片采用错缝拼装;横向刚度有效率在错缝拼装时取值范围为0.27~0.88,在通缝拼装时取值范围为0.23~0.75,且随着断面椭圆度增大而减小;通缝拼装引起的地层损失率和地表最大沉降比错缝拼装大;管片拼装过程引起的地层沉降会累积在“先盾后扩”施工总沉降中,因此应确保拼装质量,建议参照规范将通缝拼装时断面椭圆度控制在5‰以内。Based on Fujunmiaocun-Zhucun section of Xi’an Metro Line 15 constructed through the ground fissures,the segment assembling method and the impact on“shield before expansion”construction technology were discussed.The corresponding relationships between ground parameters,section ellipticity,and maximum ground settlement were theoretically analyzed.The results show that,in order to balance the convenience of expanding excavation in the fortified section and the structure stability of the normal section,the segments of fortified section should be assembled by straight joints and the key segments should be placed on the middle of the crown,the segments of normal section should be assembled by staggered joints.The transverse effective rigidity ratio of staggered joint section is at 0.27~0.88,and that of straight jointed section is at 0.23~0.75,meanwhile,transverse effective rigidity ratio decreases as section ellipticity increases.The straight joint assembling method can increase the ground loss rate and maximum ground settlement,compared with staggered joint assembling method.The settlement caused by segment assembling will be accumulated in the total settlements of“shield before expansion”,so the quality of assembling should be assured,and it is suggesged that the section ellipticity of the straight jointed section should be controlled within the standard requirements of 5‰.

关 键 词：地铁隧道 地裂缝 先盾后扩 管片拼装方式 横向刚度有效率 断面椭圆度 地表沉降 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]