顶板局部脱空状态下正交密贴下穿通道的车致振动响应研究  

Research on the Vehicle-induced Dynamic Response of Close-attached Underpass with Local Void Above Ceiling

作　　者：章慧健[1] 付柏毅 牛晓宇 王峥峥[2] 郭宏博 ZHANG Hui-jian;FU Bo-yi;NIU Xiao-yu;WANG Zheng-zheng;GUO Hong-bo(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;School of Civil Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China;Guangzhou Metro Design&Research Institute Co.Ltd.,Guangzhou 510010,Guangdong,China)

机构地区：[1]西南交通大学交通土木工程学院,四川成都610031 [2]大连理工大学土木工程学院,辽宁大连116024 [3]广州地铁设计研究院股份有限公司,广东广州510010

出　　处：《中国公路学报》2024年第4期274-285,共12页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(52178395)。

摘　　要：为研究密贴结构之间的脱空缺陷与车致振动响应之间的关系,依托新建成都地铁8号线倪家桥车站换乘通道零距离正交下穿既有1号线车站工程,采用数值模拟与现场测试手段,开展了下穿通道结构受上覆车站地铁列车动载响应特性,以及下穿通道顶板与上覆车站底板之间的脱空缺陷对该动载响应的影响规律研究。研究结果表明:下穿通道的动力响应主要受到结构与振源的相对位置和该结构的约束状态影响;从结构与振源相对位置来看,距振源较近的下穿通道顶板竖向加速度峰值大于底板;受边墙约束影响,顶板跨中处的竖向加速度峰值大于跨边,但当距离振源较远后,跨中与跨边振动响应差异不大;横向加速度表现为中隔墙大于被周边土体约束的边墙;密贴结构出现局部脱空等效于约束减弱且传递振动强的实体介质接触净面积减小,因而引发下穿结构振动响应加剧。在所提计算条件下(脱空率取5%~30%),脱空率与结构加速度和振幅响应正相关,但对下穿通道的频响曲线和时程曲线形态影响不大。此外,脱空区域与振源的相对位置对结构振动响应影响较大,当脱空区域与振源有重叠时(即振源正下方有脱空),结构加速度响应骤增。To investigate the relationship between void defects and vehicle-induced dynamic response, on-site testing was performed in this study and a dynamic numerical model was established based on a project in which the Nijiaqiao Station of Chengdu Metro Line 8 crossed the existing station with zero clearance. The influence law of void defects between the underpass roof and zero-clearance station on the vehicle-induced vibration response of the underpass was analyzed. The results show that the dynamic response of the underpass caused by the train dynamic load is mainly influenced by the relative position between the structure and the vibration source and the constraint state. The peak value of the vertical acceleration of the underpass indicates that the top plate is larger than the bottom plate. Owing to the constraint of the side wall, the midspan of the ceiling is larger than that of the side part;however, there is little difference between the midspan and the side part when it is far from the vibration source. Meanwhile, the lateral acceleration indicates that the middle wall is larger than the side part, which is constrained by the surroundings. The local voids of the close-fitting structure are equivalent to weakening the constraint and reducing the net contact area of the solid medium with strong vibration transmission, which leads to an intensified vibration response of the underpass structure. Under the calculation conditions in this study, the void ratio of 5%-30% was considered and found to have little effect on the frequency response curve and time history curve of the underpass, but shows positive correlation with the acceleration and amplitude. In addition, the relative position between the void area and the vibration source significantly influences the structural vibration response. When the void area overlaps the vibration source(i.e., a void was present under the vibration source), the structural vibration response under the overlapping area suddenly increases.

关 键 词：隧道工程 动力响应 车致振动 密贴下穿结构 局部脱空 

分 类 号：U451.3[建筑科学—桥梁与隧道工程]