摘要
以某超大直径盾构隧道工程为研究背景,开展了预加固砂土地层隧道掌子面失稳模型试验,研究了覆土埋深、加固位置对掌子面主、被动失稳及地表破坏形态的影响。结果表明:(1)预加固对于不同埋深的隧道掌子面稳定性均有所提高,当掌子面产生主动失稳破坏时,地层加固能有效降低掌子面正前方地表的沉降。对于0.75D(D为隧道直径)埋深工况,地层加固能降低8%~40%的地表沉降;对于1.25D埋深工况,则最大能降低70%的地表沉降;(2)掌子面与加固桩的水平相对位置对地表沉降影响较大,当掌子面位于加固桩正后方时,地表沉降值与未进行加固地层基本没有差别,地层加固失效。因此在预加固地层的盾构掘进施工中,需特别留意掌子面位于加固桩正后方时的施工节点,应适当加大支护压力以控制地层变形。
With a super-large diameter shield tunnel project as the research background,a model test on the tunnel face instability of the pre-reinforced sandy soil layer was carried out.The effects of the burial depth of the overburden and the reinforcement position on the active and passive instability of the tunnel face and the surface damage patterm were studied.The results show that:(1)Pre-reinforcement can improve the stability of the tunnel face at different burial depths.When the tunnel face undergoes active instability failure,the settlement of the ground surface in front of the tunnel face can be reduced effectively.For the burial depth of 0.75D(D is the tunnel diameter),the reinforcement can reduce the ground surface settlement by 8%to 40%;for the burial depth of 1.25D,it can reduce the ground surface settlement by up to 70%;(2)The horizontal relative position between the tunnel face and the reinforcement piles has a significant impact on the ground surface settlement.When the tunnel face is located just behind the reinforcement piles,the ground surface settlement is basically no different from that of the unreinforced soil layer,and the reinforcement of the soil layer fails.Therefore,in the shield tunneling construction of the pre-reinforced soil layer,special attention should be paid to the construction stage when the tunnel face is located behind the reinforcement piles,and the support pressure should be increased appropriately to control the deformation of the soil layer.
作者
昝子卉
余洪鑫
王冉
李强
苏栋
ZAN Zihui;YU Hongxin;WANG Ran;LI Qiang;SU Dong(Guangzhou Metro Design&Research Institute Co,Ltd,Guangzhou 510091;College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060;Key Laboratory of Coastal Urban Resilient Infrastructures(Shenzhen University),Ministry of Education,Shenzhen 518060;State Key Laboratory of Intelligent Getechnics and Tunelling(Shenzhen University),Shenzhen 518060)
出处
《现代隧道技术》
CSCD
北大核心
2024年第S01期759-769,共11页
Modern Tunnelling Technology
基金
国家自然科学基金(52278364,52090081)
中国国家铁路集团有限公司科技研究开发计划(K2023G042)
深圳市科技计划资助(20220810151354002)
深圳大学2035追求卓越研究计划(2022B007)
关键词
砂土
地层预加固
开挖面稳定性
破坏机理
Sandy soil
Pre-reinforcement
Stability of the excavation face
Mechanism of destruction
作者简介
昝子卉(1983-),男,硕士,高级工程师,主要从事轨道交通、地下工程等领域设计与科研工作,E-mail:290324307@qq.com;通讯作者:李强(1986-),男,博士,实验师,主要从事岩土试验及地下工程方面的研究工作,E-mail:parkli@8zu.edu.cn.
