泥岩夹砂岩顺层大跨度隧道力学特征研究  

Research on Mechanical Characteristics of Large-Span Tunnels in Bedding Mudstone with Sandstone Strata

作　　者：赵东平[1,2] 季启航 王国军 ZHAO Dongping;JI Qihang;WANG Guojun(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;China Railway Eryuan Chongqing Survey and Design Institute Co.,Ltd.,Chongqing 400023,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]西南交通大学土木工程学院,四川成都610031 [3]中铁二院重庆勘察设计研究院有限责任公司,重庆400023

出　　处：《隧道建设（中英文）》2021年第5期740-748,共9页Tunnel Construction

基　　金：中央高校基础科学研究业务费专项基金(2682019CX03);中国铁路总公司科技研究开发计划课题(K2018G057)。

摘　　要：当大跨度隧道穿越泥岩夹砂岩地层时,易产生由偏压问题导致的病害。为研究泥岩夹砂岩顺层隧道的偏压特征及影响因素,以郑万高铁重庆段小三峡隧道工程为依托,采用现场量测与数值模拟相结合的方法,对砂岩顺层倾角、间距及地下水等因素对大跨度顺层隧道力学特征的影响开展了研究。结果表明:1)相较于均质泥岩地层,泥岩夹砂岩顺层大跨度隧道开挖后,隧道周边围岩位移及塑性区均呈现非对称性,顺层法线方向围岩位移大于顺层方向;2)顺层隧道的最不利倾角为45°,当砂岩顺层间距超过3 m时,顺层对隧道力学特征的影响逐渐减小;3)含有地下水的泥岩夹砂岩地层,隧道围岩位移、泥岩塑性区及砂岩顺层塑性区范围均有所增大,围岩稳定性降低,且会加剧顺层隧道的偏压程度。When a large-span tunnel passes through mudstone with sandstone strata,diseases can be easily caused by unsymmetrical pressure.To study the unsymmetrical pressure characteristics and influencing factors of bedding tunnels in mudstone and sandstone strata,the influence of the bedding dip angle of sandstone,spacing,and groundwater on the mechanical characteristics of the large-span bedding tunnel of the Zhengzhou-Wanzhou high-speed railway is studied using field measurements and the numerical simulation method.The results show the following.(1)Compared with the homogeneous mudstone stratum,the displacement and plastic zone of the surrounding rocks around the tunnel are asymmetric after excavating the bedding of the large-span tunnel in the mudstone and sandstone strata,and the displacement of the surrounding rocks in the normal bedding direction is greater than that in the tangential direction.(2)The most unfavorable dip angle of the bedding tunnel is 45°,and the influence of bedding on the mechanical characteristics of the tunnel gradually decreases when the bedding spacing of the sandstone exceeds 3 m.(3)The displacement of the surrounding rocks,range of the mudstone plastic zone,and range of the sandstone bedding plastic zone increase in the mudstone and sandstone strata containing groundwater.Stability of the surrounding rock decreases,and the groundwater aggravates the degree of the unsymmetrical pressure of the bedding tunnel.

关 键 词：高铁隧道 泥岩夹砂岩 顺层隧道 力学特征 地下水 数值模拟 现场量测 

分 类 号：U452[建筑科学—桥梁与隧道工程]