蠕变作用下洞径对大埋深软岩盾构隧道力学特性研究  

Study on the Mechanical Characteristics of Large Burial Depth Soft Rock Shield Tunnels Affected by Hole Diameter Under Creep Effect

作　　者：侯永兵 HOU Yongbing(China Railway Construction South China Regional Headquarters,Guangzhou Guangdong 510540,China)

机构地区：[1]中国铁建股份有限公司华南区域总部,广东广州510540

出　　处：《铁道建筑技术》2023年第9期108-113,共6页Railway Construction Technology

基　　金：中国铁建股份有限公司科技研发计划项目(2017-C17)。

摘　　要：为解决大埋深软岩盾构隧道衬砌结构的稳定性问题,依托广佛环线广州南站至白云机场段工程段盾构隧道工程,采用YSJ-01-00岩石三轴压缩流变试验机对泥质砂岩试样进行了室内蠕变试验,确定了数值模拟中Cvisc模型描述隧道泥质砂岩的蠕变特性的适用性;采用数值模拟对围岩蠕变作用下大埋深软岩盾构隧道力学特性展开了探究,结果表明:蠕变过程分为逐渐衰减和稳定蠕变两个阶段,围岩蠕变会造成内力值、弯矩以及应力值增加,从而使盾构隧道管片结构变形更加严重;当洞径不同时,其产生的围岩蠕变过程中,弯矩值、轴力值、变形值、应力值的变化趋势基本相同;如果洞径持续增大,其周边的岩石产生的压力更加明显,尤其集中体现在衬砌结构(管片)上,衬砌变形程度也更大;管片衬砌外侧接触压力与洞径成正比,同时拱腰处的接触压力所受到的影响相对较大。研究结果可为大埋深软岩盾构隧道的设计和施工提供指导。To solve the stability problem of large burial depth soft rock shield tunnel lining structure,relying on the shield tunnel project of Guangzhou South Station to Baiyun Airport section of Guangzhou-Foshan Loop Line,YSJ-01-00 rock triaxial compression rheology tester was used to carry out the indoor creep test on the mud sandstone specimen,and determine the applicability of the Cvisc model in numerical simulation for describing the creep characteristics of the mud sandstone of the tunnel;and numerical simulation was used to investigate the mechanical characteristics of the tunnel under the effect of creep of the surrounding rock.The results show that:the creep process is divided into two stages of gradual decay and stable creep,the surrounding rock creep will cause an increase in the internal force value,bending moment,and stress value,which will make the deformation of shield tunnel segment structure more serious;when the hole diameter is different,the bending moment value,axial force value,deformation value and stress value in the process of surrounding rock creep are basically the same;if the hole diameter continues to be increased,the pressure generated by the surrounding rock is more obvious,especially concentrated on the lining structure(segment),and the degree of lining deformation is also greater;the contact pressure on the outside of the segment lining is directly proportional to the hole diameter,and at the same time,the contact pressure at the arch waist is relatively more affected.The results of the study can guide the design and construction of large burial depth soft rock shield tunnels.

关 键 词：大埋深软岩 衬砌结构 蠕变试验 Cvisc模型 洞径 盾构隧道 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]