张丙强, 李佳遥, 潘钦锋,等.移动荷载作用下底部脱空地基梁力学响应研究[J].河南理工大学学报（自然科学版）,doi:10.16186/j.cnki.1673-9787.2023040061.

ZHANG B Q, LI J Y, PAN Q F, et al.Dynamic responses of a beam to moving loads on elastic foundation overlyingvoids[J].Journal of Henan Polytechnic University(Natural Science) ,doi:10.16186/j.cnki.1673-9787.2023040061.

移动荷载作用下底部脱空地基梁力学响应研究(网络首发)

张丙强1, 李佳遥1, 潘钦锋1, 黄志斌2

1.福建工程学院 土木工程学院，福建 福州  350118;2.中铁二十四局集团福建铁路建设有限公司，福建 福州  350013

摘要:车辆重复荷载作用下，混凝土路面板地基时常因塑性变形、雨水冲蚀等产生局部脱空。然而， 目前采用理论方法分析路面结构的动力响应时，大都忽略了路面底部局部脱空的影响，导致理论计算值偏小。为此，将底部局部脱空的路面结构视为跨越空洞的弹性地基上的Euler梁，利用振型叠加法推 导了移动荷载作用下局部脱空地基梁的稳态响应解析解，并探讨了荷载移动速度、地基弹性系数、梁 抗弯刚度和脱空区长度对地基梁动力响应的影响。分析表明：地基梁底部局部脱空对其正上方位置梁的振动响应影响较大，而对脱空区外侧地基梁的振动影响较小；当地基梁底部脱空区宽度与梁计算长 度比为2/9时，地基梁中点振动位移最大值约为不考虑地基梁底部脱空影响时的4倍；增大地基梁抗弯 刚度和地基刚度可以减小跨越空洞区地基梁中点振动位移，但当地基梁底部脱空区宽度与梁计算长度 比大于1/3时，提高既有地基刚度的控制效果较差。

关键词:局部脱空梁;动力响应;模态叠加法;移动荷载;粘弹性地基

中图分类号：U416.01

doi:10.16186/j.cnki.1673-9787.2023040061

基金项目:国家自然科学基金资助项目（51508097）；福建省自然科学基金面上项目（2020101882）

收稿日期:2023-04-27

修回日期:2023-08-10

网络首发日期:2023-11-30

Dynamic responses of a beam to moving loads on elastic foundation overlyingvoids（Online）

ZHANG Bingqiang1, LI Jiayao1, PAN Qinfeng1, HUANG Zhibin2

1.College of Civil Engineering， Fujian University of Technology， Fuzhou  350118， Fujian， China；2.Fujian Railway Construction Co.， Ltd. of China Railway 24th Bureau Group， Fuzhou  350013， Fujian， China

Abstract:Voids beneath the concrete pavement usually generate due to plastic deformation caused by traffic load or rainwater erosion. However， the influence of voids beneath the pavement on the dynamic responses of the pavements to moving load are ignored， thus causing the theoretical results is less than the true data. To address this problem， a pavement overlying voids is simplified as an elastic beam spanning a void， and the mode superposition method is used to solve the dynamic responses of a beam to moving loads overlying voids. The influences of the parameters on the dynamic response of the beam are studied， including the moving speed of the load， the width of voids underlying the beam， the elastic coefficient of the foundation， and the bending stiffness of the beam. The results indicate that the void underlying the beam has a significant influence on the dynamic responses of the beam directly above the void， while the influence on the beam outside the void is little. When the void width is 2/9 of the length of the beam， the maximum vibrating displacement at the midpoint of the beam is about 4 times of that without considering the void underlying the beam. Increasing the bending stiffness of the beam and the elastic coefficient of the foundation can reduce the vibrating displacement at the midpoint of the beam. However， the effect of improving the foundation elastic coefficient is little when the void width the underlying the beam is 1/3 of the length of the beam.

Key words:beams overlying voids;dynamic analysis;superposition method;moving load;viscous foundation

CLC：U416.01