高铁路基粗颗粒土水力学参数测试方法研究

发布时间：2018-05-02 21:38

本文选题：路基粗颗粒土 + 渗透柱　；参考：《岩土力学》2015年12期

【摘要】：高铁路基粗颗粒土的水力学特性对路基内部水分运移及路基的长期累积变形有重要影响。而对这种高压实度的粗颗粒土,常规非饱和土试验仪器存在试样尺寸小、制样难度大的缺点,难以应用。介绍了一种用于测试高压实度路基粗颗粒土-水力学参数的试验装置,利用张力计和时域反射计量器,分别测量路基粗颗粒土在浸湿、干燥阶段不同高度处土体基质吸力、介电常数的变化情况,获得高压实度下高铁路基粗颗粒土土-水特征曲线;并通过瞬态剖面法获得路基粗颗粒土非饱和渗透系数与基质吸力的关系。试验结果表明,该套装置能够适用于最大粒径为20 mm的粗颗粒土,试样压实度最大可达到0.95。通过对一组试验结果分析,并结合Ekblad等试验结果,发现随着填料细颗粒含量增大,?(与进气值有关的参数)值逐渐减小,土体进气值增加;粒径越大,细颗粒含量越低,土体储水能力越低,对应n(与排水程度有关的参数)值越大。为路基粗颗粒土-水力学参数的测定提供了方法。
[Abstract]:The hydraulic characteristics of coarse granular soil in high-speed railway subgrade have an important influence on the internal moisture migration and long-term accumulated deformation of subgrade. For the coarse granular soil with high pressure compactness, the conventional unsaturated soil test instrument has the disadvantages of small sample size and high difficulty in sample preparation, which makes it difficult to apply. This paper introduces a test device for measuring coarse granular soil-hydraulics parameters of high-pressure compactness subgrade. By using tensor and time-domain reflectometer, the suction of subgrade coarse granular soil at different heights in wet and dry stage is measured respectively. According to the change of dielectric constant, the characteristic curves of coarse grained soil-water in high pressure subgrade were obtained, and the relationship between unsaturated permeability coefficient of coarse granular soil and the suction of matrix was obtained by transient profile method. The test results show that the device can be applied to coarse grained soil with a maximum diameter of 20 mm, and the maximum compaction of the sample can reach 0.95. By analyzing the results of a group of tests and combining with the results of Ekblad and other tests, it is found that the content of fine particles increases with the increase of filler content. The larger the particle size, the lower the content of fine particles, the lower the water storage capacity of soil, and the greater the value of N (parameters related to drainage degree). It provides a method for measuring the parameters of roadbed coarse grained soil-hydraulics.
【作者单位】：浙江大学软弱土与环境土工教育部重点实验室;浙江大学岩土工程研究所;
【基金】：国家杰出青年科学基金(No.51225804) 国家自然科学基金高速铁路基础研究联合基金重点支持项目(No.U1234204) 中国铁路总公司重大科研项目(No.2014G006)~~
【分类号】：TU43

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