新型预应力路基的静动载试验系统及应用分析  

Development and application analyses of static and dynamic loading test system for new prestressed subgrade

作　　者：徐方[1,2] 吴其长[1] 董俊利 冷伍明 张期树[3] 杨奇 XU Fang;WU Qichang;DONG Junli;LENG Wuming;ZHANG Qishu;YANG Qi(School of Civil Engineering,Central South University,Changsha 410075,China;MOE Key Laboratory of Engineering Structures of Heavy Haul Railway,Central South University,Changsha 410075,China;School of Civil Engineering,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学重载铁路工程结构教育部重点实验室,湖南长沙410075 [3]中南林业科技大学土木工程学院,湖南长沙410004

出　　处：《铁道科学与工程学报》2024年第11期4520-4531,共12页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51978672);湖南省自然科学基金青年项目(2023JJ41054)。

摘　　要：为深入研究静力加载与列车循环动荷载作用下新型预应力路基的工作性状,研制缩尺预应力路基模型试验系统(包括相似设计、模型箱构建、路基模型填筑、轨道结构设计、预应力施加方法、静力加载系统和列车动荷载模拟),开展不同预应力和列车轴重下的静动力模型试验,通过监测路基各测点处的竖向和侧向变形、加速度和动位移,量化分析施加水平预应力对路基性能的改善规律,深入分析预应力构件与路基结构的协同工作机理。研究结果表明,施加的预应力经扩散后可引起路基面产生隆起变形,当单排侧压力板施加100 kPa预压应力后,路基面最大隆起量为0.062 mm;荷载板试验中,相较于无预应力工况,预应力100 kPa下各测点处的沉降量下降了9.93%~15.77%。此外,预应力可限制荷载作用下路基坡面的外挤变形;列车动荷载试验下,各测点处的加速度和动位移均随预应力的增加而减小;预应力100 kPa下测点处的动位移幅值为无预应力工况下的82.97%~91.63%,说明施加预应力对路基的动力变形存在切实的抑制效应。研制的预应力路基静动载模型试验系统,为揭示水平预应力对路基静动力性能的强化机制提供了切实可行的物理和试验技术平台,获得的分析结果对明晰预应力加固对铁路路基服役性能的影响规律具有指导意义。To intensively study the working characteristics of a new prestressed subgrade under static and cyclic dynamic train loads,a scaled prestressed subgrade model test system(including similarity design,model box construction,subgrade model filling,track structure design,prestressed application method,static force loading system,and train dynamic load simulation)was established.The static and dynamic model tests under different prestress and axle loads were performed.By monitoring the vertical and lateral deformation,acceleration,and dynamic displacement of the subgrade at measurement points,the improvement law by applying horizontal prestress to the subgrade performance was quantitatively analyzed.The cooperative working mechanism of prestressed components and subgrade structure was analyzed.The developed static and dynamic load model test system of prestressed subgrade could provide a practical physical and experimental platform for revealing the strengthening mechanism of horizontal prestress on the static and dynamic performance of the subgrade.The test results are drawn as follow.The applied prestress can result in uplift deformation of the subgrade surface through the diffusion effect.When a prestress of 100 kPa is applied via a single row of horizontal pressure plates,the maximum uplift of the subgrade surface is 0.062 mm.In the plate load tests,compared with the non-prestressed condition,the settlement at the measurement point decreases by 9.93%~15.77%when the prestress is 100 kPa.In addition,the prestress can restrain the extrusion deformation of the subgrade slope under load.Under the simulated dynamic train loading,the acceleration and dynamic displacement at the measurement points decrease with the increase of prestress,and the dynamic displacement amplitude with a prestress of 100 kPa is 82.97%~91.63%of that without prestress.It can demonstrate that the application of prestress has a practical effect on inhibiting the dynamic deformation of the subgrade.The established test system and obtained analysis r

关 键 词：预应力路基 试验系统 静动载 变形 加固性能 

分 类 号：U213[交通运输工程—道路与铁道工程]