地铁高架桥列车振动荷载对邻近构筑物受力变形的影响  

Influences of Vibration Load of Elevated Subway Train on the Stress and Deformation of Adjacent Structures

作　　者：刘维正[1,2] 王锋 罗桂军 徐毅夫 唐新建 LIU Weizheng;WANG Feng;LUO Guijun;XU Yifu;TANG Xinjian(School of Civil Eng.,Central South Univ.,Changsha 410075,China;National Eng.Research Center of High Speed Railway Construction Technol.,Central South Univ.,Changsha 410075,China;CCFEB Civil Eng.Co.,Ltd.,Changsha 410004,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学高速铁路建造技术国家工程研究中心,湖南长沙410075 [3]中建五局土木工程有限公司,湖南长沙410004

出　　处：《工程科学与技术》2023年第6期97-108,共12页Advanced Engineering Sciences

基　　金：国家自然科学基金项目(52078500);湖南省住房和城乡建设厅科学技术计划项目(KY202108)。

摘　　要：为分析新建地铁高架桥运营期列车振动荷载对近接敏感构筑物的影响,基于长沙地铁1号线北延线高架桥上跨既有高速公路与干线铁路,针对两侧紧邻既有桥台桩基和框架桥,建立列车振动荷载下高架桥–地层–既有结构的动力耦合数值模型,分析地层与既有结构的不同深度动力响应随时间变化规律,以及列车运行速度、轴重、近接距离、地层加固模量、阻尼比分别对桥台桩基和框架桥的水平位移、速度和加速度的影响规律。结果表明:列车振动作用下,地表沉降值约为水平位移的40%,地层变形以水平位移为主。框架桥的变形、速度、加速度变化趋势与桩基类似,但其绝对值相对较小;不同深度的动力响应特征明显不同,桩顶和框架桥顶板受影响较大。既有构筑物的动力响应随速度的增加先减小后增大,且在低速区变化幅值较小,80 km/h为列车的最佳运行速度;动力响应随列车轴重的增大近似呈线性增大,轴重相对于速度对动力响应的影响明显。近接距离越小,框架桥的动力响应越大;新建桩基与框架桥水平距离小于桩径的4倍时,需采取加固措施;动力响应随加固区刚度增大而减小,地层模量达到300 MPa后,继续提高加固强度对降低响应的效果不明显。研究成果可为类似工程的建设与运营提供有益借鉴。In order to analyze the influences of train load on the proximity-sensitive structures during the operation period of the newly built subway viaduct,this study uses the example of the viaduct on the north extension line of Changsha Metro Line 1 spanning the existing expressway and main railway,and adjacent to the existing abutment pile foundation and frame bridge on both sides.The dynamic coupling numerical model of viaduct-strata-existing structure under train vibration load is employed to analyze the variation law of the dynamic response of the stratum and the existing structure at different depths,as well as the train running speed,axle load,approach distance,the modulus of the reinforced stratum,and damping ratio.The influence law is developed for horizontal displacement,velocity and acceleration of abutment pile foundation and frame bridge,respectively.The results show that:under the action of train vibration,the surface settlement value is about 40%of the horizontal displacement,and the ground deformation is dominated by the horizontal displacement.The deformation,velocity and acceleration trends of the framebridge are similar to those of the pile foundation,but their absolute values are relatively small.The characteristics of the dynamic response at different depths are obviously different,and the top of the pile and the top plate of the frame bridge are more affected.The dynamic response of the existing structure decreases and then increases with the increase of the train speed,and the change amplitude is small in the low-speed zone,while 80 km/h is the optimal running speed of the train.The dynamic response increases linearly with the increase of the axle weight of the train,and the axle weight has a significant effect on the dynamic response relative to the speed.The smaller the proximity distance is,the larger the dynamic response of the frame bridge is.When the horizontal distance between the new pile foundation and the frame bridge is less than 4 times of the pile diameter,the reinforcement measures

关 键 词：地铁高架桥 近接构筑物 列车动荷载 动力响应 数值模拟 影响规律 

分 类 号：TU997[建筑科学—市政工程]