粗粒含量对排土场堆石体剪切变形和强度的影响研究

Effect of Percentage of Coarse-grained Aggregate on Shear Deformation and Strength of Rockfill Materials in Waste Dump

为探讨粗粒含量对堆石体剪切特性的影响,采用室内中型直剪仪,对不同组构试样开展了剪切试验。研究表明,粗粒料剪切过程中没有明显的峰值强度,且应力应变关系表征为应变硬化型。相同正应力条件下,试样剪切应变达到1/100时的剪切模量随粗粒含量增加而增大,试样在破坏时的剪切模量随着粗粒含量增加呈先增大后减小的趋势,且粗粒含量为70%时试样剪切破坏模量达到最大值。粗粒料内摩擦角与粗粒含量之间存在指数关系,相关系数为0.912 6,摩擦角随粗粒含量增加而增大;粘聚力与粗粒含量间的规律性尚不明显。

Shear tests were conducted with an indoor direct shear tester lor aggregates with different percentage of coarse grains,for exploring their effects on the shear characteristics of aggregates. It is shown that no peak strength occurred during the shear test,and the stress-strain relationship of coarse aggregate was characterized by strain hardening. Under the same normal stress condition,shear modulus increased with a rise in the percentage of coarse-grained aggregate when shear strain of specimen was 1/100. Meanwhile,shear failure modulus of the specimen under failure decreased after an initial increase with the percentage of coarse-grained aggregate rising,reaching its maximum value as the percentage of coarse-grained aggregate at 70%. There is an exponential relationship between internal friction angle of coarse aggregates and its percentage. It is found that the correlation coefficient is 0.912 6 ,and frictional angle increases with the increasing of percentage of coarse-grained aggregate. However, no relationship has been found between cohesion force and percentage of coarse-grained aggregate.