含水率和固结压力对非饱和重塑湖泥力学性质的影响  

Effects of water content and consolidation pressure on mechanical properties of remolded unsaturated lake mud

作　　者：曹平[1] 欧可 韩东亚[1] 张科[1] 

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2016年第3期923-928,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51174228;51274249);国家博士点基金资助项目(20120162110009)~~

摘　　要：基于江西省城门山铜矿湖底采矿特殊的工程背景,研究湖泥在堆土固结后力学性质的变化规律及影响因素。进行6组不同含水率和4组前期固结压力下非饱和重塑湖泥的直剪试验,分析不同含水率和前期固结压力对重塑湖泥抗剪强度的影响。研究结果表明：在相同的前期固结压力下,在试验研究的含水率范围内,重塑湖泥的黏聚力和内摩擦角均随着含水率的增大而减小,且黏聚力和含水率之间基本呈负线性相关关系,拟合相关系数〉0.92,与其他含水率范围相比,重塑湖泥抗剪强度在含水率为18.62%~21.76%范围内受其变化影响更大;在相同的最终含水率下,重塑湖泥黏聚力随前期固结压力呈幂指数函数关系,而内摩擦角的变化由于存在突变,并无一定的变化规律;不同初始含水率的重塑湖泥在300 k Pa和400 k Pa固结压力下固结96 h后,最终含水率都接近于塑限（18.5%）,反算得到最佳湖泥填土高度为14 m。Based on the particular engineering background of mining from the bottom of lake at Chengmenshan Copper Mine in Jiangxi Province, the change law and influence factors of mechanical properties of lake mud after consolidation were studied. The direct shear tests with six groups of water content and four groups of consolidation pressure were conducted to study the effects of these two variables on the shear strength of remolded lake mud. The results show that the shear strength and the internal friction angles of remolded lake mud decrease with the increase of water content under the same consolidation pressure in the scope of experiment water content, and cohesion decreases linearly with water content in the rangeability of lake mud. Within the scope of 18.62%-21.76%, the water content affects the shear strength of lake mud greater than others. Under the condition of the same final water content, cohesion and previous consolidation pressure have the power exponential function relationship, but the variation of internal cohesion angles shows mutation, and there is no certain change rule. After consolidation of 96 h on different water contents of remolded soils with 300 k Pa and 400 k Pa, all of the final water contents are close to 18.5%, which is the plastic limit of the remold lake mud. The best height of soil slope is 14 m by back calculation, which can be used in engineering application for reference.

关 键 词：直剪实验 重塑湖泥 抗剪强度 含水率 固结压力 

分 类 号：TU411[建筑科学—岩土工程]