含水率及干密度对重塑红黏土强度的影响

Effects of Moisture Content and Dry Density on Shear Strength of Remolded Red Clay

为探究武汉重塑非未饱和红黏土抗剪强度特征,利用直剪试验研究了干密度、含水率对抗剪强度的影响.试验结果表明:(1)在干密度1.4g/cm^(3),w∈[22.5%,30%]的控制条件下,随含水率升高抗剪强度变化幅度较小,w>30%,抗剪强度急剧衰减;含水率增长有利于胶结作用形成,粘聚力随含水率增高先增高后减小;在一定的范围内,内摩擦角降幅较小,含水率超过30%,内摩擦角急剧衰减.(2)在含水率25%的控制条件下,随干密度增大,抗剪强度、粘聚力、内摩擦角均线性增长,剪切位移曲线由弱软化型转变为强软化型.

This study investigates the shear strength characteristics of Wuhan remolded red clay and examines the influence of dry density and moisture content on shear strength of unsaturated remolded red clay with direct shear test.The experimental results show that under the condition of the dry density being 1.4g/cm ^(3),with the increases of moisture content,the cohesive force of the remolded red clay increases first and then decreases,and when the water content is 27%,the cohesive force is the highest with the increases of moisture content,the internal friction angle and fluctuates within a small range first and then when the moisture content exceeds 30%,the internal friction angle decreases sharply;under the condition of moisture content being 25%,with the increases of dry density,the shear strength,cohesion and internal friction angle of red clay increases linearly,and the stress-strain relationship changes from a weakly softening type to a strong softening type.