钙质砂抗剪强度的试验研究
Experimental Study on the Shear Strength of Calcareous Sand

文章主要是通过对钙质砂和硅质砂进行直剪试验，探究钙质砂的剪切破坏和抗剪强度与硅质砂的区别，并对钙质砂设置不同的孔隙比和颗粒级配、以及干砂与湿砂的对比试验，研究多种参数对钙质砂抗剪强度的影响。结果表明：钙质砂的黏聚力随着不均匀系数增加先减小后增大，而内摩擦角先增大后减小；钙质砂的黏聚力和内摩擦角均随着孔隙比增加而减小；钙质湿砂的黏聚力和内摩擦角均比钙质干砂的小；随着剪切位移随来越大，硅质砂的剪应力先增大后减小，出现明显的峰值，钙质砂的剪应力持续增大；同等条件下，钙质砂的黏聚力和内摩擦角都远大于硅质砂。
This article mainly conducts direct shear tests on calcareous sand and siliceous sand to explore the differences in shear failure and shear strength between calcareous sand and siliceous sand. Different pore ratios and particle sizes are set for calcareous sand, as well as comparative tests between dry and wet sand, to study the influence of various parameters on the shear strength of calcareous sand. The results show that the cohesive force of calcareous sand decreases first and then increases with the increase of non-uniformity coefficient, while the internal friction angle increases first and then decreases; The cohesion and internal friction angle of calcareous sand decrease with the increase of pore ratio; The cohesive force and internal friction angle of calcareous wet sand are smaller than those of calcareous dry sand; As the shear displacement increases, the shear stress of siliceous sand first increases and then decreases, showing a clear peak, while the shear stress of calcareous sand continues to increase; Under the same conditions, the cohesion and internal friction angle of calcareous sand are much greater than those of siliceous sand.