新型预应力路基静力加固性能与机理研究  

Static reinforcement performance and mechanism of new prestressed embankment

作　　者：张期树 冷伍明[1,2] 徐方[1,2,3] 阮波[1,2,3] 董俊利 ZHANG Qishu;LENG Wuming;XU Fang;RUAN Bo;DONG Junli(School of Civil Engineering,Central South University,Changsha 410075,China;Key Laboratory of Engineering Structure of Heavy Railway,Central South University,Changsha 410075,China;Hunan Tieyuan Civil Engineering Testing Co.,Ltd.,Changsha 410075,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]湖南铁院土木工程检测有限公司,湖南长沙410075

出　　处：《铁道科学与工程学报》2023年第7期2488-2499,共12页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51978672);湖南铁院土木工程检测有限公司检测研究基金资助项目(HNTY2021K09)。

摘　　要：预应力路基作为一种新型铁路路基结构形式和路堤快速加固技术,其实际加固性能与机理方面的研究还相对滞后。以重载路基为背景,通过填筑室内大比尺物理路基模型,对其开展条形荷载板试验,主要测试分析路基在3种不同加固状态下路基面沉降、边坡侧向变形的变化规律。此外,为进一步探究预应力差异化加固模式对路基承载变形特性的影响,建立与条形荷载板试验相匹配的三维有限元模型,开展多工况数值仿真对比计算,重点探究加固结构布设位置、排数以及不同预应力大小对路基体受荷变形规律的影响。研究结果表明:预应力路基在控制路基面沉降和坡面侧向变形方面较普通路基存在显著优势,预应力加固结构可有效提升路基的弹性工作区间,延缓路基进入塑性发展阶段,且其加固效果随分级荷载的增大得以逐步显现。在控制路基边坡侧向变形方面,增加加固排数是最有效的加固途径。在排数限定时,考虑在坡面侧向变形最大区域布置加固结构对约束边坡整体变形最有利,提高预应力也可进一步限制边坡侧向变形。因预应力钢筋具有较高的抗拉强度,可与路基体协同承载抗变形。研究结果论证了预应力路基的加固效果,并初步揭示了其作用机理。The study regarding the actual reinforcement performance and mechanism of prestressed subgrade,as a new subgrade structure and a rapid reinforcement technique for embankment,is relatively lagging.Based on a heavy haul subgrade,the strip plate load tests on indoor large-scale physical subrgade model were carried out to analyze the embankment settlement and slope lateral deformation of subgrade under three reinforcement conditions.Furthermore,to further investigate the effect of the differential reinforcement modes for prestressed reinforcement structure,including reinforcement structure positions,rows and reinforcement pressures,on the subgrade bearing deformation behavior,a 3D finite element model matched with the strip loading plate test was established to make a comparative numerical calculation for multiple reinforcement cases.The results are drawn as follows.In contrast with ordinary subgrade,the prestressed subgrade has the significant advantages in controlling the surface settlement and slope lateral deformation,and the reinforcement structure can effectively improve the elastic capacity of subgrade or delay it enter plastic stage,and the reinforcement effect was gradually exhibited with increasing the loading steps.In controlling the slope lateral deformation,increasing rows is the most effective solution.While with limitation of rows,it is most favorable solution that with consideration of placing reinforcement structure on the maximum lateral deformation zone of slope in the ordinary subgrade case to restrict the slope overall deformation.Besides,improving reinforcement pressure can also further restrict this deformation behavior.Owing to the steel bar having higher tensile strength,it can bear the loads and resist deformations together with the subgrade.The research results demonstrate the reinforcement effect of prestressed subgrade and reveal its working mechanism preliminarily.

关 键 词：预应力路基 加固性能与机理 荷载板试验 数值仿真 差异化加固 

分 类 号：TU473[建筑科学—结构工程]