Geotechnical Properties of Diatom soft Rock and Stability Analysis of Cut Slope

第一部分介绍了大分县的硅藻土已成为新建高速公路和路堑边坡底基的对象。硅藻土颗粒是多孔材料，含水量很高，如有明粘土。胶结效果强，但干燥和润湿作用下软化现象明显。第一部分认为，坡面物理化学性质和力学性质、坡面稳定性、硅藻土的稳定利用是本研究的重要内容。第二部分描述了沉积在日本和大分县的分布。第三部分介绍了九州问题土壤的理化性质，并与九州问题土壤的理化性质进行了比较。在第4部分中进行了一些实验室试验，在第5部分中研究了反复干燥和湿润对机械性能的影响。抗压强度的下降大于抗拉强度的下降。利用这些试验结果，在第6部分对边坡进行了有限元分析。在最坏的情况下，边坡会因抗拉强度下降而发生破坏。第7部分介绍了生石灰和水泥的稳定，以及稳定硅藻土的力学性能。

Part 1 describes that the Diatom earth in Oita prefecture has been an object of subbase of new free way and cut slope. The Diatom earth particle is porous material and water content is very high such as Ariake clay. Cementation effect is very strong, however slaking phenomenon is remarkable by drying and wetting. This part 1 concludes that physical and chemical properties and mechanical properties, stability of cut slope, utilization of Diatom earth by stabilization are important subjects in this research.Part 2 describes the distribution of deposition in Japan and Oita prefecture. Part 3 shows physical and chemical properties, and compared above properties with that of some problematic soils in Kyusyu.Some kinds of laboratory tests were performed in Part 4, and effects of repetition of drying and wetting on mechanical properties were investigated in Part 5. The decrease in compressive strength is greater than that in tensile strength. Using these test results, some finite element analyzes were carried out for the slope in Part 6. The slope failure will occur due to the decreasing in tensile strength in the worst case. Part 7 describes the stabilization by quick lime and cement, and mechanical properties of stabilized diatom earth.