Study on Undrained Shear Strength of Colluvium

• Main Authors: Pei-yu Chen, 陳佩玉
• Other Authors: Shiou Chen
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/46398079314715509052

碩士 === 華梵大學 === 環境與防災設計學系碩士班 === 97 === Landslide of colluvium often occurs due to the change of groundwater table accompanied with the reduction of effective stress of soil stratum and the factor of safety from slope stability analysis. To avoid the risk of the landslide, the understanding of the soil properties through the concerned soil tests are always needed. In this study, the colluviums samples are collected from Huafan University’s campus on Mt. Da-lum that are used to obtain the basic characters of soils by making necessary experiments, and direct shear test is performed to obtain the variation of the shearing stress parameter of colluviums slope affected by the ground water soaking. The vane (torvane) shear tests and fall cone tests, called penetrated tests in this study, are also performed on these same remolded soil samples so that the corresponding relationship of undrained shear strength among the results obtained via different approaches may be achieved. It is also expected to find a way to estimate the shear strength in-situ from the results obtained at laboratory tests by applying the correlation factors K. It is found from the results that the undrained shear strength obtained from vane shear test has obvious tendency when the soaking time increased and is smaller than that obtained from direct shear test. The K value 0.38-0.44 and 0.62-0.69 of fall cone test is suggested when soil is unsaturated and saturated for the direct shear tests, respectively. And, 0.02-0.06 is suggested for the results obtained by vane shear test.