散粒体卸载特性的三轴伸长试验研究

根据岩土体的加卸载变形过程和应力状态,卸载曲线分为弹性卸载段和卸载伸长段.采用三种不同粒径的玻璃珠和标准丰浦砂散粒材料进行了三轴伸长卸载试验,对比分析了不同材料、初始偏应力和不同围压下散粒体的卸载特性.研究表明散粒体的单向伸长卸载强度主要取决于与卸载方向垂直的围压和颗粒的内摩擦,且与围压成线性关系,初始偏应力状态及各向异性对于散粒体的伸长强度无影响,但影响其破坏发展形态.此外,材料特性包括表面粗糙度和级配、孔隙率等对内摩擦及伸长卸载特性均有影响.

TRIAXIAL EXTENSION TEST STUDY ON THE UNLOADING BEHAVIOR OF GRANULAR

Unloading curve of soil was divided into elastic unloading and extension unloading accor-ding to the deformation process and stress state.Three kinds of grain size of glass beads and standard Toyoura sand were used to do triaxial extension test; influence of material,initial deviator stress and confining pressure on the unloading behavior were compared.It was announced that the uniaxial extension strength mainly depends on the confining pressure perpendicular to the unloading direction and the friction of m...