上软下硬复合地层基于衬砌结构弯矩最小化的隧道横断面优化设计  

Tunnel Cross-section Optimization Design in Upper-soft Lower-hard Composite Strata Based on Lining Structure Minimum Bending Moment

作　　者：张慧鹏 张涛[2,3] 石钰锋[2,3] 赖世华 刘巍 ZHANG Huipeng;ZHANG Tao;SHI Yufeng;LAI Shihua;LIU Wei(Nanchang Rail Transit Group Co.,Ltd.,330038,Nanchang,China;State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure,East China Jiaotong University,330013,Nanchang,China;Jiangxi Key Laboratory of Infrastructure Safety Control in Geotechnical Engineering,East China Jiaotong University,330013,Nanchang,China;East China Survey and Design Co.,Ltd.of China Railway Eryuan Engineering Group Co.,Ltd.,310004,Hangzhou,China;Nanchang Rail Housing and Bridge Building Materials Co.,Ltd.,330096,Nanchang,China)

机构地区：[1]南昌轨道交通集团有限公司,南昌330038 [2]华东交通大学轨道交通基础设施性能监测与保障国家重点实验室,南昌330013 [3]华东交通大学江西省岩土工程基础设施安全与控制重点实验室,南昌330013 [4]中铁二院华东勘察设计有限责任公司,杭州310004 [5]南昌轨道房桥建材有限公司,南昌330096

出　　处：《城市轨道交通研究》2024年第8期186-191,199,共7页Urban Mass Transit

基　　金：国家自然科学基金面上项目(42177162);江西省重点基金项目(20202ACB202005)。

摘　　要：[目的]为有效防止隧道衬砌破损及渗漏水,对上软下硬复合地层隧道横断面进行衬砌结构弯矩最小化设计研究。[方法]根据复合地层隧道围岩压力特点及合理假设,提出软土-硬土及土-岩两类复合地层隧道衬砌结构荷载作用模式。基于最理想的零弯矩复合地层隧道优化思路,建立隧道横断面半结构力学模型,计算得出零弯矩隧道横断面合理轴线方程,以及复合地层分界线处及隧道横断面水平中线处直径解析表达式。简述了复合地层隧道横断面弯矩最小化设计流程。[结果及结论]软土-硬土隧道零弯矩横断面合理轴线呈梨形,土-岩隧道零弯矩横断面合理轴线呈类马蹄形;实际工程可基于隧道横断面合理轴线方程,通过综合评估和加权平均法来确定隧道横断面设计所需关键参数,从而设计出新型上软下硬地层隧道横断面,以期最大限度减少复合地层隧道横向变形。[Objective]To effectively prevent lining damage and water leakage in tunnels,research is carried out on minimizing lining structure bending moment for tunnel cross-section in upper-soft lower-hard composite strata.[Method]Soft soil-hard soil and soil-rock two types of loading modes for composite strata tunnel lining structures are proposed based on composite strata tunnel surrounding rock pressure characteristics and reasonable assumptions.Following the ideal optimization approach for a zero bending moment composite strata tunnel,a semi-structural mechanics model of tunnel cross-section is established.The rational axis equation of the zero bending moment tunnel cross-section and the analytical expressions of diameters at both composite strata boundary lines and the horizontal tunnel cross-section mid-line are calculated.The process of minimizing bending moment in composite strata tunnel cross-section is outlined briefly.[Result&Conclusion]The rational axis of the zero bending moment cross-section in soft soil-hard soil tunnel is pear-shaped,while in soil-rock tunnel,it is horseshoe-shaped.In practical engineering,based on the rational axis equation of tunnel cross-section,key parameters for tunnel cross-section design can be determined through comprehensive evaluation and weighted averaging method.This approach enables the design of new tunnel cross-sections in upper-soft and lower-hard strata,aiming to minimize lateral deformation in composite strata tunnels.

关 键 词：轨道交通 隧道横断面 衬砌结构 弯矩最小化 上软下硬复合地层 

分 类 号：U452.29[建筑科学—桥梁与隧道工程]