不同颗粒级配尾砂稳态强度特性试验研究  

Experimental study on steady-state strength characteristics for tailings sand with different grain size distribution

作　　者：潘建平[1] 刘湘平[1] 王宇鸽[1] 

机构地区：[1]江西理工大学建筑与测绘工程学院,江西赣州341000

出　　处：《中国安全生产科学技术》2014年第6期39-44,共6页Journal of Safety Science and Technology

基　　金：国家自然科学基金项目(51204076);江西省自然科学基金项目(20114BAB216011);江西省科技支撑计划项目(20133BBG70103);江西省教育厅科学技术研究项目(GJJ12340)

摘　　要：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 tailings 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 likelihood 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.

关 键 词：尾砂 颗粒级配 稳态强度 砂土液化 

分 类 号：X936[环境科学与工程—安全科学]