深埋风积沙地层隧道掌子面失稳特征研究  

Research on the Instability Characteristics of the Tunnel Face in Deep-buried Aeolian Sand Stratum

作　　者：王志杰[1] 吴凡 王如磊 王李 高靖遥 蒋新政 周平[1] 李学广 WANG ZWjie;WU Fan;WANG Rulei;WANG Li;GAO Jingyao;JIANG Xinzheng;ZHOU Ping;LI Xueguang(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;China Railway Eryuan Engineering Group Co.Ltd,Chengdu,Sichuan 610031,China;Western Investment Co.Ltd of CCTEB,Chengdu,Sichuan 610041,China;China Railway 18 Bureau Group First Engineering Co.Ltd,Zhuozhou,Hebei 072750,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031 [2]中铁二院工程集团有限责任公司,成都610031 [3]中建三局西部投资有限公司,成都610041 [4]中铁十八局集团第一工程有限公司,涿州072750

出　　处：《铁道工程学报》2020年第1期85-92,共8页Journal of Railway Engineering Society

基　　金：国家自然科学基金项目(51678498);教育部创新团队发展计划资助项目(IRT0955);中央高校基本科研业务专项资金资助项目(SWJTU11ZT33)。

摘　　要：研究目的:风积沙是一种黏聚力低、自稳能力差的土体,给隧道设计和施工带来很大困难。本文研究旨为揭示不同掌子面角度下深埋风积沙地层隧道的掌子面失稳特征,从而反馈设计施工。研究结论:(1)掌子面前方失稳区呈楔形状,再向上扩展形成封闭的灯泡状区域,随着掌子面角度增大,失稳区下部扩大,上部缩小,掌子面稳定性逐渐改良;(2)掌子面角度对于失稳区的纵向、横向尺寸影响不大,失稳区前边界约为掌子面前方1倍洞径处,横向跨度约为2倍洞径;(3)失稳土体中存在压力拱,其顶点位于拱底上方1~2倍洞径间,随着掌子面角度增大,失稳区形成的压力拱顶点在下移,跨度在减小;(4)本文推导了适用于深埋风积沙地层的掌子面支护力计算公式,并提出了相关设计施工建议;(5)本研究成果可应用于深埋风积沙隧道,尤其是台阶法或盾构法开挖的隧道。Research purposes:Aeolian sand is a soil with low cohesion and poor self-stability,which brings great difficulties to tunnel design and construction.The purpose of this paper is to reveal the instability characteristics of the face of the deep-buried aeolian sand tunnel under different face angles,and to feed back into design and construction.Research conclusions:(1)The instability zone in front of the face has a wedge shape and then expands upward to form a closed bulb-like area.As the angle of the face increases,the lower part of the instability zone expands,the upper part shrinks,and the stability of the face is gradually improved.(2)The angle of the face has little effect on the longitudinal and lateral dimensions of the instability zone.The boundary is about 1 times of hole diameter,and the lateral span is about 2 times of hole diameter.(3)There is a pressure arch in the unstable soil,and the apex is located between the hole and the bottom of the arch.As the angle of the face increases,the apex of the pressure arch formed by the instability zone moves downward and the span decreases.(4)This paper deduces the formula for calculating the support force of the face in the deep-buried aeolian sand stratum,and puts forward relevant design and construction suggestions.(5)The research results can be applied to deep-buried aeolian sand tunnels,especially tunnels excavated by step method or shield method.

关 键 词：蒙华铁路 深埋风积沙隧道 掌子面失稳特征 掌子面角度 数值模拟 理论分析 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]