随机均匀长颗粒链结构土体强度模型研究

土体的强度问题要远远复杂于金属材料,是目前的一个难点和热点问题。从已有的文献看,学者们提出了很多的强度理论模型,但这些模型大多建立在假设和实验的基础上,其更深层次的理论研究还比较欠缺。该文通过对随机均匀网状颗粒链结构土体模型分析,从理论上得到了类似于剑桥强度模型的帽子模型,且通过不同的假定,可以导出在π平面上的不同强度曲线(曲面)。得出结论：最保守情况下的强度曲线(曲面)是π平面上正六边形,在纵向为二次曲线型的帽子模型。另外发现,当颗粒链受到破坏,链长度越来越短时,强度曲面的顶点向无限远处移动,形成接近开口的强度曲面形式,也就是从剑桥帽子模型过渡到锥形的莫尔-库仑(Mohr-Coulomb)模型。也就是说,长颗粒链模型将剑桥模型和莫尔-库仑(Mohr-Coulomb)模型联系和统一了起来。

A STRENGTH MODEL OF SOIL MASS WITH RANDOM UNIFORM LONG PARTICLE CHAIN STRUCTURE

Strength and stability of soil mass, far more complex than those of metals, are two major and heatedly discussed issues in soil mechanics. Various strength models have been published in literature. However, most models are associated with assumptions or rely on experimental analysis with limitations, with fundamental theories insufficiently explored. In this study, a hat model which is similar to the Cambridge strength model is proposed based on the studies of soil mass with random uniform mesh particle chain structure. Various strength curves on the π plane have been derived subjected to different assumptions. The most conservative case can be represented by a hat model with a strength curve being regular hexagon on the π plane and parabolic in the longitudinal direction. When the particle chain is damaged and the length of the chain is becoming shorter, vertices of the strength curve move towards infinity, and form a curve with an opening. That is, the Cambridge hat model is transformed into the conical Mohr-Coulomb model. The long particle chain model essentially unifies the Cambridge strength model and the Mohr-Coulomb model.