粘土材料单轴压缩及强度特性试验研究

为探讨压实粘土材料在单轴加载条件下的强度及变形特性,考虑含水率、干密度、各向异性、碎石掺量等因素,对立方体压实粘土材料进行了单轴压缩试验,并分析了弹性模量、抗压强度的参数相关性。试验结果表明,随着含水率的减小或干密度的增加,压缩粘土材料弹性模量、抗压强度逐渐增加,其中,含水率是控制压实粘土材料脆韧性破坏特征的主要因素;当单轴加载方向与击实方向平行时,其抗压强度、弹性模量分别为加载方向与击实方向垂直时的1.7、1.1倍,说明压实粘土存在一定的各向异性;掺入碎石后使得压实粘土材料内部存在大量的软弱界面,随着碎石增多,其抗压强度逐渐减小;掺碎石前、后的粘土试样的弹性模量和抗压强度呈现一定的正相关性,可采用幂函数、线性函数进行拟合,但碎石的掺入降低了其相关性系数。

Experimental Study on Uniaxial Compression and Strength Characteristics of Clay Materials

In order to explore the strength and deformation characteristics of clay materials under uniaxial loading, uniaxial compression test was carried out on the cubic compacted clay material considering water content, dry density, anisotropy, stone content and other factors. And then the parameter correlations of elastic modulus and compressive strength were analyzed. The experimental results show that the elastic modulus and compressive strength of clay materials increase gradually with the decrease of moisture content or the increase of dry density. When the uniaxial loading direction is parallel to the compaction direction, the compressive strength and elastic modulus are 1.7 times and 1.1 times respectively when the loading direction is perpendicular to the compaction direction, indicating that the compaction clay has certain anisotropy. After adding crushed stone, a large number of soft interfaces existed in the compacted clay material. With the increase of crushed stone, its compressive strength gradually decreased. The elastic modulus and compressive strength of the clay samples before and after the mixture of gravel were positively correlated, and power function and linear function could be used to fit the sample.