地铁盾构并行下穿既有明挖隧道加固方案研究——以济南黄河隧道北岸段地铁下穿明挖公路隧道为例  

Reinforcement Scheme for Open-Cut Highway Tunnel Parallelly-Crossed by Metro Shield Tunnel on North Bank Section of Yellow River-Crossing Tunnel in Jinan,China

作　　者：傅金阳[1,2] 张洪瑜 孙前辉 张亮亮 阳军生[1] 李亚楠[4] FU Jinyang;ZHANG Hongyu;SUN Qianhui;ZHANG Liangliang;YANG Junsheng;LI Yanan(School of Civil Engineering,Central South University,Changsha 410075,Hunan,China;National Engineering Research Center for High Speed Railway Construction Technology,Changsha 410075,Hunan,China;China Railway Siyuan Survey and design group Co.,Ltd.,Wuhan 430063,Hubei,China;Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou 450003,Henan,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]高速铁路建造技术国家工程研究中心,湖南长沙410075 [3]中铁第四勘察设计院集团有限公司,湖北武汉430063 [4]黄河勘测规划设计研究院有限公司,河南郑州450003

出　　处：《隧道建设（中英文）》2023年第S02期418-427,共10页Tunnel Construction

基　　金：国家自然科学基金项目(52078496,51878669);湖南省交通运输厅科技进步与创新项目(202117)。

摘　　要：为解决公轨合建水下隧道分离后,地铁隧道长距离并行近接下穿明挖隧道过程中面临的变间距下穿扰动、地层脱空的问题,以济南黄河隧道北岸段地铁下穿明挖公路隧道为依托,建立考虑可张开地层-结构界面和结构变形缝的精细化三维仿真模型,探究不同加固方案下盾构施工对地层脱空及既有结构的影响。结果表明:1)相比于无加固措施,采用立柱桩加固后,最大地表沉降减少52%,沉降曲线峰值叠加效应得到有效控制;2)采用立柱桩配合三轴搅拌桩加固,盾构下穿过程中既有结构底板横向最大差异沉降减少43.4%,最大沉降降低47.0%;3)无加固措施下,盾构掘进导致既有隧道结构底板与地层之间脱空效应明显,最大脱空位移达1.44 mm,相比于三轴搅拌桩加固,采用立柱桩加固更能有效减少结构底板脱空;4)无加固措施下既有结构最大拉应力增量超限(1 MPa),采用单一三轴搅拌桩加固有增大既有结构注浆范围内拉应力增量趋势,而采用立柱桩配合三轴搅拌桩加固,可有效减少50%的既有结构拉应力增量。盾构并行下穿既有结构时,相比显著强化单一加固措施,综合考虑地层位移控制(防脱空)和结构应力控制的加固措施更加安全有效。After the separation of the highway and railway in an underwater tunnel,varying spacing underpass disturbance and detachment between soil-structure occurred during a metro tunnel parallelly crossing an existing opencut tunnel.In this study,a case study is conducted on the metro tunnel on the north bank section of the Yellow rivercrossing tunnel in Jinan,China,and a refined three-dimensional simulation model considering the detachable stratastructure interface and structural deformation joint is established to investigate the influence of shield tunneling on stratum-structure detachment and the existing structure under various reinforcement schemes.The results reveal the following:(1)The maximum ground settlement is reduced by 52%and the peak superposition effect of the settlement curve is effectively controlled after the column pile reinforcement is adopted.(2)The maximum lateral differential settlement and the maximum settlement of the existing structure floor are reduced by 43.4%and 47.0%,respectively,during shield tunneling after using reinforcement of column pile and three-axis mixing pile.(3)The maximum detachment between the tunnel floor and the soil due to shield tunneling is 1.44 mm without reinforcement.Compared with the reinforcement of three-axis mixing pile,the reinforcement of column pile is more effective in reducing the detachment between the tunnel floor and the soil.(4)The maximum tensile stress increment of the existing structure without reinforcement measures exceeds the control limit,and the reinforcement of three-axis mixing pile tends to increase the tensile stress increment within the grouting range of the existing structure,while the use of column pile combined with three-axis mixing pile reinforcement can effectively reduce the tensile stress increment of the existing structure by 50%.When shield tunneling parallelly under existing structure,it is safer and more effective to take the ground displacement control(anti-detachment)and structural stress control into consideration than to stren

关 键 词：地铁盾构 既有明挖公路隧道 立柱桩 三轴搅拌桩 底部脱空 结构变形 应力增量 

分 类 号：U459[建筑科学—桥梁与隧道工程]