铁路隧道铺底混凝土顶面纵向裂纹扩展研究  

Study on longitudinal crack propagation on top surfaceof railway tunnel bottom concrete

作　　者：折惠东 李又云[2] SHE Hui-dong;LI You-yun(CSCEC AECOM CONSULTANTS Co.,LTD.,Lanzhou 730000,China;Chang’an University,Xi’an 710064,China)

机构地区：[1]中国市政工程西北设计研究院有限公司,甘肃兰州730000 [2]长安大学,陕西西安710064

出　　处：《河南城建学院学报》2025年第2期27-33,共7页Journal of Henan University of Urban Construction

基　　金：陕西省自然科学基础研究计划项目(2016JM5090)。

摘　　要：为了探讨铁路隧道铺底混凝土顶面纵向裂纹的扩展规律,采用断裂力学理论和有限元软件ABAQUS对隧道铺底结构中心、轨道与枕木端等3个位置的纵向裂纹扩展进行了模拟计算。在围岩压力与列车动载的耦合作用下,对铺底结构纵向裂纹的应力强度因子与扩展路径进行了分析。结果表明:列车动载对纵向裂纹扩展具有显著促进作用,对K_(Ⅱ)影响更为明显。当中心处、轨道处与枕木端处的裂纹深度分别为180、140、100 mm时,3个位置裂纹尖端K_(Ⅰ)达到最大值。随着裂纹扩展深度的增加,对裂纹尖端K_(Ⅱ)的影响程度逐渐增大,尤其是对枕木端K_(Ⅱ)影响更为明显。在裂纹扩展过程中,初期阶段由K_(Ⅰ)主导,后期阶段由K_(Ⅱ)主导,3个位置裂纹扩展的最大深度均为0.8 m。这可为隧道结构设计及裂纹整治提供一定的理论参考依据。In order to study the crack propagation behavior of longitudinal cracks on the top surface of tunnel bottom concrete,fracture mechanics theory and the finite element software ABAQUS were applied to numerically simulate the propagation of longitudinal cracks at three locations:the tunnel bottom structure center,track,and tie end.The study analyzes the stress intensity factors(K-values)and propagation paths of these longitudinal cracks in the context of the surrounding rock pressure and the coupled effect of train dynamic loads.The results show that dynamic loads from the train significantly promote the propagation of longitudinal cracks,with a more notable effect on K_(Ⅱ).When the crack depth at the center,track and tie end is 180,140 and 100 mm,respectively,the crack tip K_(Ⅰ)at the three positions reaches the maximum value.As the crack depth increases,the influence on the crack tip K_(Ⅱ)gradually increases,particularly on the tie end K_(Ⅱ).During the crack propagation process,the initial stage is mainly dominated by K_(Ⅰ),while the later stage is mainly governed by K_(Ⅱ).The maximum crack propagation depth at all three locations is 0.8 meters.The research findings provide theoretical guidance and references for tunnel design and crack remediation.

关 键 词：铁路隧道 铺底结构 纵向裂纹 断裂力学 扩展规律 强度因子 

分 类 号：U459.1[建筑科学—桥梁与隧道工程]