砂砾石混合物抗剪强度特性试验研究

为分析砾石含量及砾石形状对砂砾石混合物抗剪强度的影响，对砂砾石混合物进行了不同应力（σ=50、100、150、200kPa）条件下的大型直剪试验。试验中砂砾石混合物为相同砂与圆砾石及角砾石2种不同形状砾石的混合物，砾石含量分别为20％、40％、60％及80％。结果表明砂砾石混合物的剪胀量和抗剪强度随砾石含量以及砾石形状不规则程度的增加而增加，砾石含量对砂砾石混合物抗剪强度的影响大于砾石形状的影响。砂砾石混合物的最小孔隙比可以作为衡量砾石含量和砾石形状与其抗剪强度关系的特征参数。

Experimental Analysis on Shear Strength Characteristics of Sand-Gravel Mixtures

The effect of gravel content and shape on shear strength of sand-gravel mixtures was investigated through a series of direct shear tests under different stress states （σ= 50,100,150 and 200 kPa） in laboratory. Mixtures were made up of sand with rounded and angular gravels, respectively. The gavel contents of 20%, 40%, 60% and 80% were used in sample preparation. The results indicate that the dilatancy and shear strength of sand-gravel mixture increase with increasing gravel content and irregular degree of gravel shape. The gravel content has a more visible effect on the shear strength rather than that of the gavel shape. The minimum void ratio of the mixture is a characteristic parameter to investigate the relationship between gravel content ＆ shape and the shear strength of sand-gravel mixture.