高铁荷载下软土地基振动与塑性变形特性  

Vibrations and plastic deformations of soft ground induced by high-speed trains

作　　者：纪颖波 张继严 毕俊伟 高广运[3] 徐晨晓 李燕姚 JI Yingbo;ZHANG Jiyan;BI Junwei;GAO Guangyun;XU Chenxiao;LI Yanyao(School of Civil Engineering,North China University of Technology,Beijing 100144,China;School of Transportation Civil Engineering,Shandong Jiaotong University,Jinan 250357,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;Chongqing Expressway Group Co.Ltd.,Chongqing 401120,China)

机构地区：[1]北方工业大学土木工程学院,北京100144 [2]山东交通学院交通土建工程学院,山东济南250357 [3]同济大学土木工程学院,上海200092 [4]重庆高速公路集团有限公司,重庆401120

出　　处：《中南大学学报(自然科学版)》2024年第12期4615-4627,共13页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(42277130);山东省自然科学基金青年面上项目(ZR2024QE495)。

摘　　要：为明确高铁运行引起的软土地基塑性变形特性,将高铁动荷载下地基振动小应变问题视为材料非线性问题,视地基土体为弹塑性介质,基于2.5维有限元法、后向欧拉积分算法和一致切线刚度法,推导列车-轨道-弹塑性软土地基振动变形的2.5维有限元计算方法。以上海典型软土地基为例,研究轨道平滑的准静态列车荷载和考虑轨道不平顺的修正列车荷载引起的地基振动与塑性变形特性。研究结果表明:这两类列车荷载引起的最大振动位移均出现在轨道下方地表处,振动位移沿地表和深度的衰减速率随车速提高逐渐提高。相较于准静态列车荷载,当车速为200 km/h时,轨道不平顺对振动位移的影响可忽略;当车速接近或超过临界速度时,修正列车荷载下软土地基中的振动波叠加干涉现象更为强烈,且振动位移显著增大,轨道不平顺的影响显著。两类列车荷载下地基土体塑性变形主要集中在距轨道中心水平4.0 m、深度2.0 m以内,存在下沉和隆起的塑性变形区,轨道不平顺引起塑性变形增大数倍。软土地基的振动位移和塑性变形在准静态荷载下由类共振条件控制,而在修正列车荷载下受轨道不平顺激励力和移动轮轴力产生的振动波叠加效应影响显著,由类共振条件和轨道不平顺激励力共同控制。For clarifying the plastic deformation characteristics of ground under high-speed train loads,the ground vibrational deformation caused by high-speed train load was considered a material nonlinear problem,treating the soft soil as elastoplastic media,based on the two-and-a-half dimensional(2.5D)approach and introducing the consistent tangent stiffness method and Euler stress integration algorithm,a 2.5D finite element model was established for train-track-elastoplastic ground vibration deformation by high-speed train loads.Taking typical soft soil ground in Shanghai as an example,the vibration displacement and plastic deformation of ground under quasi-static train loads for smooth track and train loads modified by track unevenness were investigated.The results show that the maximum vibration displacements under both types of train loads occur at the ground surface beneath the track,and as speed increases,so does the attenuation rate along the ground surface and at depth.Compared to the quasi-static train load,the influence of track unevenness can be ignored at a train speed of 200 km/h,and as the train speed approaches or surpasses the critical speed,the modified train load leads to a stronger superposition of vibration waves generated in the soft ground and a significant increase in vibration displacement.Under two types of train load,the plastic deformation of the ground is mainly located within a horizontal distance of 4.0 m and a depth of 2.0 m from the center of the track,with existing subsidence and upliftment plastic deformation zones,and plastic deformation would be multiplied by track unevenness.Furthermore,the vibration displacement and plastic deformation of soft ground are governed by the like-resonance condition under quasi-static loads,while under modified train loads,they are significantly impacted by the superposition effects of vibration waves triggered by the track unevenness excitation force and the moving axial force,and governed both by the like-resonance condition and the track unevenness ex

关 键 词：塑性变形 高速铁路 软土地基 弹塑性 2.5维有限元模型 

分 类 号：TU435[建筑科学—岩土工程]