Study on the Sedimentary Environment and the Estimation of Shear Strength of Sand Ground

颗粒材料的强度特性符合摩擦规律。此外，颗粒间摩擦角和颗粒接触点角主要由物理描述控制。据说，像沙子这样的粒状材料的动态特性取决于它们的主要性质（如土壤类型、大小分布、颗粒形状）和次要性质（如密度、含水量、框架结构）。因此，如果能够感知到这些相互之间的关系，则无需进行任何剪切试验就可以推测出颗粒材料的粒间摩擦角。至此，笔者发现颗粒材料的粒间摩擦角主要受颗粒形状的影响。此外，作者还揭示了它们几乎是成比例的，而没有考虑其他主要属性，如大小分布。本研究收集了不同粒径分布、颗粒形状和粒度的不同颗粒材料的剪切试验数据，提出了仅根据颗粒形状和相对密度推定颗粒间摩擦角的方法。然后，通过二维铝棒剪切试验，考察了颗粒形状和表面粗糙度对颗粒间摩擦角、剪切强度、剪切线等剪切特性的影响。此外，还对砂的粒度进行了分析，其中砂的粒度分布和颗粒形状是自然积累的。然而，这些物理描述在深度方向上受到了诸如海侵/海退等运输和沉积环境的影响。

The strength characteristic of granular material is according to the friction rule. In addition, inter-granular friction angle and particle contact point angle are mostly controlled by the physical description. It is said that the dynamic characteristic of granular material like sand depends on their primary properties (ex ; soil type, size distribution, particle's shape) and secondary properties (ex; density, water content, framed construction). Therefore, if the relation of these mutual can be perceived, inter-granular friction angle of the granular material will able to be presumed without doing any shearing test. So far, the writer had figured out that the inter-granular friction angle of granular material is mostly influenced by the particle's shape. Besides, the writer also revealed that they are almost proportionally to each other, without considering to the rest of primary properties such as size distribution.In this research, the data of shearing test of various granular materials (which differ in size distribution, particle's shape and size) had been gathered and the method of presuming the inter-granular friction angle only by the particle's shape and the relative density is proposed. Then, by performing two-dimensional aluminum rod shearing test, the effect of particle's shape and surfaces roughness on the shearing characteristics such as inter-granular friction angle, shearing strength, shearing lines etc. had been examined. In addition, the particle size of the sand had been analyzed , where the sand's size distribution and particle's shape are accumulated naturally. And yet, what kind influent that these physical descriptions had, caused by the transportation and sedimentary environment such as transgression/regression in depth direction, had been examined.