回填层与管片组合结构的支护性能及模型试验研究  

Supporting Performance and Model Test of Backfill Layer and Segment Combined Structure

作　　者：吴圣智 黄群伟 王明年[1,2] 姜志毅 刘大刚[1,2] WU Shengzhi;HUANG Qunwei;WANG Mingnian;JIANG Zhiyi;LIU Dagang(School of Civil Engineering,Southwest Jiaotong University,Chengdu Sichuan 610031,China;Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest JiaotongUniversity,Chengdu Sichuan 610031,China;Bridge and Tunnel Design Department,China Railway First Survey andDesign Institute Group Co.,Ltd.,Xi an Shaanxi 710043,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [3]中铁第一勘察设计院集团有限公司桥梁隧道设计处,陕西西安710043

出　　处：《中国铁道科学》2018年第5期73-79,共7页China Railway Science

基　　金：国家自然科学基金资助项目(51208434);重庆市应用开发计划重点项目(cstc2014yykfB30003)

摘　　要：双护盾隧道掘进机倒梯形设计及管片拼装特点使得管片与围岩之间存在一定的空隙,常采用碎石回填并注浆形成回填层。将回填层与管片视为组合结构,采用弹性力学中厚壁圆筒理论,推导组合结构支护刚度计算公式,分析回填层对组合结构支护性能的影响及回填层的承载能力、吸收变形能力,并设计相似模型试验进行验证。结果表明:回填层可以承担少量的荷载并吸收部分围岩变形,其承载能力与吸收变形的能力与回填层的弹性模量有关;回填层存在1个临界弹性模量,当回填层实际弹性模量小于临界弹性模量时组合结构的支护刚度小于管片支护刚度,当大于临界弹性模量时组合结构的支护刚度大于管片支护刚度。实际工程中,注浆固结后的回填层弹性模量处于0.8~1.5GPa之间,此时回填层的主要作用是在围岩与管片之间传递荷载。The inverted trapezoid design of double shield tunnel boring machine and the characteristics of segment assembly leave some spaces between the segmentand surrounding rock.Gravel backfilling and grouting are often used to form the backfill layer.Considering the backfill layer and segment as a combined structure,the calculation formula for the support stiffness of the combined structure is derived by adopting the theory of thick-walled cylinder in elastic mechanics.The influence of backfill layer on the supporting performance of the combined structure as well as the load bearing capacity and absorptive deformation capacity of backfill layer are analyzed.Also,similar model tests are designed toverify the results.Results show that the backfill layer can bear a small amountof load and absorb part of surrounding rock deformation.Its load bearing capacity and absorptive deformation capacity are related to the elastic modulus of thebackfill layer.There is a critical elastic modulus in the backfill layer.Whenthe actual elastic modulus of the backfill layer is less than the critical elastic modulus,the support stiffness of the combined structure is smaller than that of the segment,and when it is greater than the critical elastic modulus,thesupport stiffness of the combined structure is larger than that of the segment.In practical engineering,the elastic modulus of the backfill layer is between 0.8 GPa and 1.5 GPa after the grouting is consolidated.At this time,the mainfunction of the backfill layer is to transfer the load between the surrounding rock and the segment.

关 键 词：双护盾隧道掘进机 回填层 管片 支护性能 临界弹性模量 模型试验 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]