架空式桩板结构动力特性原位激振试验研究  

In-situ forced vibration tests on dynamic characteristics of overhead pile-plate structure

作　　者：邓浩然 肖杭 余雷 褚宇光[2] 黄俊杰[1] 苏谦[1] DENG Haoran;XIAO Hang;YU Lei;CHU Yuguang;HUANG Junjie;SU Qian(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China;China Railway Economic Planning Research Institute,Beijing 100038,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中铁二院工程集团有限责任公司,四川成都610031 [3]中国铁路经济规划研究院有限公司,北京100038

出　　处：《铁道科学与工程学报》2023年第12期4592-4603,共12页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52078434);中国铁路总公司科技研究开发计划重点课题(2017G008-C);四川省青年科技创新研究团队项目(2022JDTD0015)。

摘　　要：架空式桩板结构路基在非埋式桩板结构路基的基础上不再设置桩周路基填土,具有一定架空高度,有效减少了路基填料用量,降低了路基建设占地和缩减了施工周期。然而,由于板-土之间无直接传力,架空式桩板结构路基动力荷载传递模式发生改变,其是否还具有良好的动力特性尚处未知。因此,依托贵南高铁某架空式桩板结构路基试验段工程,开展了原位扫频激振试验。试验结果表明,在2~15Hz变频动载作用下,架空式桩板结构路基动力响应随加载频率增加呈指数式增长规律,各项振动响应参数变化无峰值,反映在激振频率范围内架空式桩板结构路基未发生共振现象;承载板、托梁和桩基动应力总体上随激振频率的增大呈线性增长,架空式桩板结构主筋动应力从上部承载板至下部桩基呈较小增大规律,这说明架空式桩板结构路基能够有效地将上部动载产生的动应力通过承载板和托梁传递至桩基;架空式桩板结构路基综合动刚度随加载频率增加呈线性增大规律,对比非埋式桩板结构路基和传统土质填筑路基,架空式桩板结构路基具有更大的综合刚度,能有效抵抗外荷载引起的变形。综合变频试验结果可知,架空式桩板结构路基具有良好的受力与变形协调特性和振动特性。研究成果可为架空式桩板结构路基的推广应用提供理论支撑。On the basis of the non-embedded pile-plate subgrade structure,the overhead pile-plate subgrade structure no longer sets the soil around the pile and has a certain overhead height,which effectively reduces the amount of filling,the roadbed construction area,and the construction period.However,there is no direct force transfer between plate and soil,the dynamic mechanical properties of the overhead pile-plate subgrade structure changes,and it remains unknown whether it still has satisfactory dynamic characteristics.Therefore,based on an overhead pile-plate structure subgrade test section project of the Guizhou-Nanning high-speed railway,a field sweeping vibration test was carried out.The test results show that the dynamic responses of overhead pile-plate subgrade structure increase exponentially with the increase of loading frequency under the dynamic load with variable frequency of 2~15 Hz,and there is no peak in the change of each vibration response parameter.In the range of excitation frequency,no resonance phenomenon occurs in the overhead pile-plate subgrade structure.The dynamic stress of the bearing plate,joist and pile foundation increases linearly with the excitation frequency,and the dynamic stress of the overhead pile-plate subgrade structure increases gradually from the upper bearing plate to the lower pile foundation,which indicates that the overhead pile-plate subgrade structure can effectively transfer the dynamic stress generated by the upper dynamic load to the pile foundation through the bearing plate and joist.The comprehensive dynamic stiffness of overhead pile-plate subgrade structure increases linearly with the increase of loading frequency.Compared with non-embedded pile-board subgrade structure and traditional soil-filled subgrade,overhead pile-plate subgrade structure has greater comprehensive stiffness of subgrade and can effectively resist the deformation caused by external loads.According to the results of frequency conversion test,the overhead pile-plate subgrade structure has good str

关 键 词：铁路路基 架空式桩板结构路基 原位激振试验 动力特性 变频加载 

分 类 号：U213.1[交通运输工程—道路与铁道工程]