城市深埋黏土隧道变形破坏机制试验研究  

Experimental research on deformation and failure mechanism of deep-buried clay tunnels in urban areas

作　　者：邱居涛 申玉生[1,2] 赵何霖 朱正超 喻炳鑫 董俊[3] 苟安迪 QIU Jutao;SHEN Yusheng;ZHAO Helin;ZHU Zhengchao;YU Bingxin;DONG Jun;GOU Andi(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;National Engineering Research Center of Geological Disaster Prevention Technology in Land Transportation,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]西南交通大学陆地交通地质灾害防治技术国家工程研究中心,四川成都610031 [3]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《岩石力学与工程学报》2023年第11期2765-2775,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：“十三五”国家重点研发计划(2019YFC0605104);中铁第四勘察设计院集团有限公司科研课题(2022K005,2022K006)。

摘　　要：为研究城市深埋黏土隧道受力特性及变形破坏机制,开展室内相似模型试验。采用自主研制的隧道全断面掘进试验装置,运用位移、土压力、应变量测装置及石英砂标记方法,研究开挖过程及不同埋深下隧道受力与变形特征,分析衬砌结构的最终破坏形态,通过数值模拟证实模型试验的有效性。研究结果表明:隧道开挖后土体裂纹集中分布于开挖面左上方且以压剪破坏为主,隧道开挖引起了土体的纵向不均匀沉降且邻近洞口段土体沉降最大;在50~500 m埋深条件下,土体沉降随着深度的增大而减小,土压力竖向衰减幅值大于横向,隧道结构拱底土压力最大,右拱腰和拱顶次之,左拱腰最小,隧道能够承受的埋深极限为150m;受非对称荷载作用,衬砌右部结构破坏比左部严重,衬砌结构收敛变形类似“横鸭蛋”形状,洞口段拱顶向内收敛最显著,而衬砌末端水平扩张变形明显。试验结果揭示了深埋黏土隧道地层–结构相互作用机制,为深埋地铁隧道安全施工提供了参考依据。In order to investigate the deformation characteristic and failure mechanism of deep-buried clay tunnels in urban,the similarity model test was conducted in this paper.The full-section excavation apparatus of tunnels was used in the model test.The displacement,ground pressure and strain devices were adopted to explore the tunnel mechanical responses under different buried depths.The failure modes of the tunnel lining were analyzed,and the effectiveness of model test was verified by numerical simulation.The results indicate soil cracks induced by compression-shear stress are distributed above the tunnel face after tunnel is excavated.The uneven longitudinal settlement of soil is induced by excavation,and the settlement near the entrance of tunnel is the most significant.Under the buried depth of 50–500 m,the soil settlement decreases with the increase of the depth,and the attenuation magnitude of the ground pressure in the vertical direction is greater than that in the horizontal direction.The ground pressure is the most significant at the tunnel invert,followed by the right tunnel waist and the crown.The left tunnel waist has the smallest ground pressure.The bearing capacity of the tunnel lining reaches the limit when the buried depth is 150 m.The damage of the right part of the lining is more severe than that on the left part under asymmetric loads,and the convergence deformation of the lining is similar to“horizontal egg”shape.The convergence of the tunnel crown at the entrance of the tunnel is the most significant,while the largest horizontal expansion occurs at the end of the lining.The test results reveal the interaction between the surrounding soil and tunnel structure of deep-buried clay tunnel.It will provide references for the safety of deep-buried metro tunnel construction.

关 键 词：隧道工程 变形机制 破坏特征 模型试验 深埋黏土隧道 

分 类 号：U45[建筑科学—桥梁与隧道工程]