颗粒级配是影响土体剪切强度的主要因素之一。通过配置三组不同级配尾砂试样，每组均在100kPa、200kPa、300kPa围压下分别进行不同初始孔隙比的固结不排水剪切试验，研究不同级配下尾砂的剪切特性及稳态强度特性，求出三种级配尾砂的稳态线及稳态内摩擦角。试验结果表明：在低围压时，各级配下饱和松散尾砂的应力-应变曲线呈软化型，且随着围压增高，软化越不明显。平均粒径越小的尾砂，其峰值强度与稳态强度越小，稳态线越靠近e-q坐标系的原点，即在同一荷载作用下，发生液化的可能性越大。为此，有必要加强细粒尾砂堆筑坝体液化势的评估，以防液化溃坝灾难的发生。%Grain size distribution is one of the main factors affecting the soil shear strength .By configuring three groups tailings sand samples with different gradations and initial void ratio , the consolidated undrained shear tests were conducted to study the shear properties and steady strength characteristics , and obtain three steady-state lines and steady-state internal friction angles .The test results showed that the stress-strain curves of saturated loose tail-ings sand are softening at low confining pressure , with higher confining pressure , the softening is less obvious . When the average particle size is smaller , the peak intensity and the steady state intensity are smaller .The steady state lines are closer to the origin of the e-q coordinate system , i.e., under the same load , the occurrence likeli-hood of the liquefaction is greater .For this reason , it is necessary to strengthen liquefaction potential evaluation for the fine tailings dam , in order to prevent the occurrence of liquefaction and dam disaster .
展开▼
