地道桥下穿高速公路动态施工过程数值模拟  

Numerical simulation on the dynamic construction process of underpass bridges crossing highways

作　　者：陈孝轩 CHEN Xiaoxuan(Guangdong Brigade of China Geological Survey Center of Building Materials Industry,Guangzhou 510403,Guangdong,China)

机构地区：[1]中国建材地勘中心广东总队,广东广州510403

出　　处：《工程建设》2024年第4期25-30,共6页Engineering Construction

摘　　要：地道桥顶推下穿是一种高效且经济的解决路线交叉问题的施工方案,明确施工时地道桥的受力机理有助于优化设计,因此有必要对地道桥下穿过程进行模拟研究。文章以湖南省某公路地道桥下穿G4高速为例,基于有限差分法,对下穿顶推施工过程进行了数值模拟分析,研究得出地道桥盾构法动态施工过程应力场与位移场变化的规律。研究结果表明:随着顶推的进行,掌子面后方土层应力变化明显,影响范围在掌子面后6 m左右。同时,摩阻力系数与地层条件特别是土质情况联系密切,顶推施工时,箱涵底部产生的摩阻力占比超过总摩阻力的70%,计算结果明确了地道桥顶推过程中的受力特征与作用机理,能为类似的地道桥下穿施工提供合理的借鉴与参考。The top pushing underpass of an underpass bridge is an efficient and economical construction plan to solve the problem of route intersection.Clarifying the stress mechanism of the underpass bridge during construction can help optimize the design.Therefore,it is necessary to conduct simulation research on the underpass process of the underpass bridge.A highway underpass bridge in Hunan Province was taken as an example,and based on the finite difference method,numerical simulation analysis is carried out on the underpass top pushing construction process.The law of stress field and displacement field changes during the dynamic construction process of the underpass bridge shield tunneling method is studied.The research results indicate that as the top push progresses,the stress in the soil layer behind the palm face changes significantly,with an impact range of about 6 meters behind the palm face.At the same time,the friction coefficient is closely related to the geological conditions,especially the soil conditions.During the top pushing construction,the friction generated at the bottom of the box culvert accounts for more than 70%of the total friction.The calculation results clarify the stress characteristics and mechanism of the underpass bridge during the top pushing process,which can provide reasonable reference and guidance for similar underpass bridge construction.

关 键 词：顶推地道桥 动态施工 极限摩阻力 极限顶力 数值模拟 

分 类 号：U445.4[建筑科学—桥梁与隧道工程]