溶洞上覆砂性地层盾构隧道合理布置位置研究  

Study on Reasonable Position Selection of Shield Tunnel in Sandy Stratum Overlying Karst Cave

作　　者：王亚[1] 王士民[1] 孙雪兵[2] WANG Ya;WANG Shimin;SUN Xuebing(Key Laboratory of Transportation Tunnel Engineering of the Ministry of Education,Southwest Jiaotong University,Chengdu Sichuan 610031,China;China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan Hubei 430063,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,四川成都610031 [2]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《铁道建筑技术》2022年第6期58-62,74,共6页Railway Construction Technology

基　　金：国家自然科学基金项目(51991394)。

摘　　要：文章以武汉地铁11号线三期工程江安路站-复兴路站盾构区间为工程依托,在数值模拟软件ANSYS中通过弱化溶洞上方松散区域砂土的物理力学性能来表征溶洞的塌陷,建立隧道-隔离桩-溶洞三维有限元模型,探讨隧道距离砂层-灰岩界面不同净距时位于左线隧道正下方的溶洞诱发上覆砂层塌陷对周边地层及既有盾构隧道管片结构的影响,为实际工程隧道位置布置提供有效参考。研究结果表明:在隧道拱底距离砂层-灰岩界面6~12 m范围时,随着净距减小地表沉降增大,而净距为3 m时地表沉降反而减小;综合分析盾构管片变形值和应力值随竖向净距的变化规律可知,在实际工程中,宜将盾构隧道位置布置在距砂层-灰岩界面8 m以上范围。Based on the shield section between Jiang’an Road Station and Fuxing Road Station of Wuhan Metro Line 11 phase Ⅲ project,this paper established a three-dimensional finite element model of tunnel-isolation pile-karst cave by weakening the physical and mechanical properties of the sand in the loose area above the cave to characterize the collapse of the cave with the numerical simulation software ANSYS.The influence of the overlying sand layer collapse induced by the karst cave directly under the left tunnel under different clear distances between the tunnel and the sand-limestone interface on the surrounding stratum and the segment structure of the existing shield tunnel was discussed,and an effective reference for the selection of the tunnel position in the actual project was provided.The results show that:when the arch bottom of the tunnel is 6~12 m away from the sand-limestone interface,the surface settlement increases with the clear distance decreasing.When the clear distance is 3 m,the surface settlement decreases.Based on the comprehensive analysis of the variation law of the deformation and stress of the segment with the vertical clear distance,it can be seen that the shield tunnel should be located at a distance of more than 8 m from the sand-limestone interface in practical engineering.

关 键 词：盾构隧道 变形与应力 数值模拟 溶洞塌陷 隧道位置 

分 类 号：U455.49[建筑科学—桥梁与隧道工程] U231.2[交通运输工程—道路与铁道工程]