路用红砂岩碎石土湿化变形特性试验  

Test on wetting deformation of red sandstone gravel soil in filled subgrade

作　　者：韦慧[1] 曾胜[1] 赵健[1] 李振存[1] 李文[1] 胡甜[1,2] 

机构地区：[1]长沙理工大学交通运输工程学院,湖南长沙410004 [2]中交第二公路勘察设计研究院有限公司,湖北武汉430056

出　　处：《中南大学学报（自然科学版）》2015年第6期2261-2266,共6页Journal of Central South University:Science and Technology

基　　金：教育部新世纪优秀人才支持计划项目(NCET-11-0977);西部交通建设科技项目(2011318824350);湖南省交通科技进步与创新项目(201204)~~

摘　　要：针对湿热地区红砂岩碎石土用作路基填料易发生湿化崩解,导致路基刚度软化及其耐久性能降低的问题,采用自行研制的大型干湿循环压缩剪切仪,开展不浸水条件与反复浸水下红砂岩碎石土的一维大型压缩试验,揭示红砂岩填料在干湿循环条件下的湿化压缩变形规律。研究结果表明:湿化变形量随浸水次数增加而增加,压缩模量在前2次干湿循环过程中衰减幅度较大,第3次后逐渐趋于稳定;地基土附加湿化变形量随浸水时间增加而增大,变形模量随含水率增加而减小。试验结果可为红砂岩填筑路基的安全施工及其长期沉降预测提供依据。Considering that wetting disintegration is easy to take place in red sandstone gravel soil, which leads subgrade stiffness to soften and decrease its durability, one-dimensional compression test of red sandstone gravel soil was tested at repeated soaking and un-soaking status by using large-scale compression direct shear apparatus for wetting-drying cycle, and the wetting deformation law of red sandstone filling was revealed under wetting-drying cycle status. The results show that the wetting deformation is improved with the increase of soaking times, and compression modulus is gradually reduced, both of which are changed greatly in the first two soaking under wetting-drying cycle status and then are gradually stabilized. At different soaking time, additional wetting deformation of foundation soil is improved with the increase of soaking time, and attenuation increases with the increase of water content. The test results provide reliable basis for safe construction of filling subgrade with red sandstone and long-term subsidence prediction.

关 键 词：道路工程 红砂岩 湿化变形 刚度 大型压缩试验 载荷板试验 

分 类 号：U416.1[交通运输工程—道路与铁道工程]