非饱和重塑Q_2黄土抗剪强度指标试验研究

Experimental Study on Shear Strength Indices of Unsaturated Remolded Lishi Loess

采用非饱和土总应力强度公式,通过室内直剪试验研究了含水量、干密度对非饱和重塑Q_2黄土抗剪强度指标的影响,得到了抗剪强度指标随含水量、干密度变化的基本规律和拟合公式,并且采用最小二乘法建立了考虑含水量和干密度同时变化时抗剪强度指标的计算公式。研究表明:非饱和重塑Q_2黄土抗剪强度指标与含水量、干密度密切相关,其中黏聚力与含水量呈良好的一阶指数衰减关系,与干密度呈二次曲线关系;内摩擦角对含水量有较大灵敏性,与含水量呈二次曲线关系,受干密度影响较小;含水量和干密度的交互作用可按乘法效应进行组合。

Based on the total stress intensity formula of the unsaturated soil,the effect of the water content,dry density to the shear strength characteristics of unsaturated remolded Lishi （ Q2 ） loess we e studied by the indoor direct shear tests. The basic rules and fitting formula of shear strength index and water content,dry density were obtained and the formula of shear strength index was established under the simulta-neous change of water content and dry density by the least square method. The study shows that strength of Lishi （ Q2） loess has close con-nection with water content and dry density,a remarkable exponential relation is found between cohesion and water content,moreover the rela-tion between cohesion and dry density is conic ; the internal friction angle has a great sensitivity to water content and the relation is conic,but it is less afected by the diy density. The interaction effect of ＂water content and dry density can be expressed by multiplication.