赣南花岗岩残积土路基变形规律的数值仿真  

Numerical Simulation of Deformation Rule of Granite Residual Soil Subgrade in Southern Jiangxi

作　　者：费伦林 纪更占 林盛[2] FEI Lun-lin;JI Geng-zhan;LIN Sheng(Jiangxi Provincial Expressway Investment Group Co.,Ltd.,Nanchang Jiangxi 330025,China;Key Laboratory of Road and Traffic Engineering of Ministry of Education,Tongji University,Shanghai 201804,China)

机构地区：[1]江西省高速公路投资集团有限责任公司,江西南昌330025 [2]同济大学道路与交通工程教育部重点实验室,上海201804

出　　处：《公路交通科技》2020年第3期41-48,69,共9页Journal of Highway and Transportation Research and Development

基　　金：江西省交通运输重点科研项目(2015C0026,2015C0025)。

摘　　要：为研究赣南花岗岩残积土路基的变形规律,基于非饱和土流固耦合理论,采用Geostudio软件对其进行了数值仿真分析,并通过实际监测数据验证所建数值模型的可靠性。数值模型分析了9种路基压实状态、5个路基填筑高度和4类填筑速率条件下非饱和花岗岩残积土路基变形的变化规律。结果表明:在90%和94%压实度下,路基总变形、地基工后变形、路基工后压缩变形和路基不均匀变形随初始含水率的增加,均呈现出先减小后增大的规律,在最大承载比含水率下变形量最小;路基总变形和工后总变形的最大值,和填筑高度呈抛物线关系;随着填筑高度的增加,地基工后变形占路基工后总变形的比例仍保持在70%以上;路基填筑施工时,分阶段填筑的路基最大总变形要小于一次性填筑的路基,且填筑速率越快,变形量越大,工后固结变形占工后总变形的比例也越大。因此,建议在填筑路基时,应采用分阶段填筑,并合理控制填筑速率;对于天然含水率较高的花岗岩残积土,可以以最大承载比含水率为施工控制含水率,并可针对现场压实困难的情况,适当降低压实度控制标准。To investigate the deformation rule of granite residual soil subgrade in the southern Jiangxi, according to the fluid-solid coupling theory of unsaturated soil, the numerical simulation is performed on the deformation of subgrade based on Geostudio software, and the reliability of the proposed numerical model is verified by actual monitoring data. The deformation rules of unsaturated granite residual soil subgrade under the conditions of 9 subgrade compaction states, 5 subgrade filling heights and 4 construction speeds are analysed by the proposed numerical model. The result shows that(1) under the compaction degree of 90% and 94%, total deformation of subgrade, post construction deformation of foundation, post construction compression deformation and differential deformation of subgrade decreased firstly and then increase with the increase of initial water content. and the minimum deformation values are obtained at the water content of maximum bearing ratio;(2) the maximum values of the total deformation and the post construction deformation demonstrate parabola relationships with filling height;(3) the proportion of the post construction deformation of foundation to total post construction deformation of subgrade remains larger than 70% with the increasing of filling height;(4) in subgrade filling construction, the total subgrade deformation by multistage construction is smaller than that by one time construction, the subgrade deformation and the proportion of post construction consolidating deformation to total post construction deformation are all increased with the increase of construction speed. Therefore, it is suggested to fill granite residual soil subgrade by stages and control the filling rate reasonably, to fill granite residual soil subgrade with the water content of maximum bearing ratio for the granite residual soil with higher natural water content, and release the compaction control standard properly when facing the compaction difficulty.

关 键 词：道路工程 变形 数值仿真 花岗岩残积土 压实状态 

分 类 号：U414[交通运输工程—道路与铁道工程]