不同颗粒排列对砂土力学特性的影响研究

Effects of different particle arrangements on mechanical properties of sand

土的结构性研究的根本任务是寻找一种能够全面反映土粒排列和胶结特征的定量化指标。通过对不同颗粒排列方式下结构性砂土展开三轴固结排水剪切试验,研究了不同的颗粒排列方式对砂土力学特性及其应力-应变特性的影响效应,初步探索了颗粒的排列对砂土强度的影响规律。试验结果表明:相对密实度大的试样的内摩擦角值均高于相对密实度小的;相对密实度相同时,混合试样的内摩擦角明显高于排列试样,从下到上颗粒由大到小排列样的强度最大,反之对应的强度最小;这对工程实践,尤其是公路、铁路等路基填方工程有较好的指导意义。

The purpose of the study on soil structure is to find a quantitative index which can comprehensively reflect the characteristics of particle arrangement and cementation of soil.By means of the laboratory triaxial consolidation drainage shear tests on the mechanical properties of sand under different particle arrangements,the influences of different particle arrangement on the mechanical properties of structural sand are studied,the stress-strain characteristics were summarized and analyzed,and the effects of the particle arrangement on the strength of sand are studied.The results show that the internal friction angle of the samples with high relative compaction is higher than that with low relative compaction.When the relative compaction is the same,the internal friction angle of the mixed samples is obviously higher than that of the other samples;the strength is the largest when the particles of the samples are arranged from large to small(from bottom to top),on the contrary,the strength is the minimum.This study is of good guiding significance for engineering practice,especially for foundation filling projects such as highways and railways.