杭州典型非饱和砂质粉土的力学特性试验研究

发布时间：2018-07-09 14:14

本文选题：非饱和土 + 含水量　；参考：《浙江工业大学》2014年硕士论文

【摘要】：本文对杭州地区典型的非饱和砂质粉土进行了研究,通过不固结快剪和固结不排水剪的直剪试验,探究了含水量和干密度这两个单一变量对抗剪强度参数的影响。又通过控制干密度的土水特征曲线试验探究了基质吸力对该土样抗剪强度参数的影响以及干密度对基质吸力的影响。通过试验研究主要得到了以下几点结论：(1)不固结快剪试验和固结不排水剪试验中的粘聚力都是随着含水量的增大先变大再变小。而内摩擦角都是随着含水量的增加而减小。不固结快剪试验中含水量对内摩擦角的影响要略大于固结不排水剪试验。(2)不固结快剪试验和固结不排水剪试验中的粘聚力和内摩擦角都是随着干密度的增大而增大。在不固结快剪试验中,干密度对内摩擦角的影响随着含水量的增加而变大。(3)三个不同的干密度下粘聚力都随着基质吸力的增大先变大再减小,且剧烈变化主要出现在土水特征曲线的毛细水作用区。基质吸力都是随着内摩擦角的增大而增大,且基质吸力越大,对内摩擦角的影响越小。干密度越大,土样进气值越高,残余含水量越低,残余吸力越大。(4)总体来讲,含水量及干密度的变化对该土样的抗剪强度指标具有规律性的影响,同时基质吸力也对该砂质粉土的抗剪强度有明显的规律性的贡献。
[Abstract]:In this paper, the typical unsaturated sandy silt in Hangzhou area is studied. Through the direct shear tests of unconsolidated fast shear and unconsolidated undrained shear, the effects of water content and dry density on shear strength parameters are investigated. The influence of the matrix suction on the shear strength parameters and the effect of dry density on the matrix suction were also investigated by the soil-water characteristic curve test of controlling dry density. The main conclusions are as follows: (1) the cohesion of the unconsolidated fast shear test and the unconsolidated undrained shear test firstly increases and then decreases with the increase of water content. The angle of internal friction decreases with the increase of water content. The effect of water content on the angle of internal friction in unconsolidated fast shear test is slightly greater than that in unconsolidated undrained shear test. (2) the cohesive force and the angle of internal friction increase with the increase of dry density in the unconsolidated fast shear test and the unconsolidated undrained shear test. In the unconsolidated fast shear test, the effect of dry density on the angle of internal friction increases with the increase of water content. (3) the cohesion of three different dry densities increases first and then decreases with the increase of the matrix suction. The sharp changes occurred mainly in the capillary water action area of soil water characteristic curve. The suction of matrix increases with the increase of internal friction angle, and the greater the suction of matrix, the less the influence on the angle of internal friction. The higher the dry density, the higher the air intake value, the lower the residual water content and the greater the residual suction. (4) generally speaking, the variation of water content and dry density has a regular effect on the shear strength index of the soil sample. At the same time, the matrix suction also has obvious regular contribution to the shear strength of the sandy silt.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU411

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