砂土粒间胶结性对砂土力学性质影响的三轴实验研究

Triaxial Compression Test Investigation of Sand Particles Cemetation Effects on Mechanical Properties of Coarse Sand

摘要: 本文采用对砂土进行胶结的混合法，在砂土中掺入硅酸盐水泥制成不同水泥含量的人工胶结砂土试样，通过对试样进行三轴固结排水剪切试验，研究砂土颗粒间的胶结对砂土强度特性，应力-应变特性及体积变形特性的影响。研究表明，同一围压下试样水泥含量越高粗砂粒间的胶结越强，试样的峰值强度越大；但同一围压下不同水泥含量试样的残余强度接近相等。同一围压下，试样水泥含量越高砂粒间的胶结越强，试样的初始压缩模量越大，应变软化越明显。试样水泥含量越高粗砂粒间的胶结越强，在低围压下排水剪切时越容易发生剪切膨胀，低围压下排水剪切时的体应变也越大。

Abstract: In this paper, the mixing method is adopted to cement sand, and artificial cement sand samples of different cement content are made by mixing Portland cement with sandy soil. Triaxial consolidation drained shear tests on these sand samples are carried out to study effects of the cementation between sand particles on strength characteristics, stress-strain characteristics and the volume change characteristics. Studies show that under the same confining pressure, the higher the cement content and the stronger the bonding between the coarse sand particles, the bigger the peak shear strength of the artificial cement sand samples, but the residual shear strength of samples of different cement content is approximately equal. The higher the cement content and the stronger the bonding between the coarse sand particles, the bigger the initial compression modulus and the more obvious strain softening of the samples of different cement content under the same confining pressure. The higher the cement content and the stronger the bonding between the coarse sand particles, the more easily the artificial cement sand samples to dilate and the bigger the volumetric strain of these samples.