The effect of clay seam on the failure surface development of rock slope

• Main Authors: Chih-Kai Yang, 楊智凱
• Other Authors: Zon-Yee Yang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/58881398686348957520

碩士 === 淡江大學 === 土木工程學系碩士班 === 103 === In recent years, dip slope often create major damage and failure surface always development along shale. When slope slide, we can estimate landslide''s shear strength by back calculation. But back calculation of the shear strength different from lab test of the shear strength. Dip slope have bedding structures, then layers always have clay layer or seam by bedding shear. In this study, we against clay seam and failure surface development, research the effect of clay seam on the failure surface development of rock slope. Hoping to find better interpretation of back calculation of the shear strength different from lab test of the shear strength. And research slope failure factors at 3.1K of the Third Freeway in Taiwan. In this study, we research the effect of clay seam on the failure surface development of rock slope through numerical analysis. Research the effect of clay seam on the geometric properties and shear strength, then use gravity increase method to observed failure surface development. The following conclusions are drawn：(1)Pointed out in different geological to investigate the effect of clay seam on the failure surface development of rock slope. Clay seam by bedding shear and shale soften by water is more important on slope stability. (2)Use gravity increase method by FLAC gradually change acceleration of gravity of material, can quick observation the failure surface development of rock slope. (3)Clay seam on the geometric properties can influences slope stability and failure surface development. Failure surface slide position will change by clay seam position. When clay seam on slope toe will be most danger. Slop have clay seam will influence slope stability, but change thickness of clay seam will not influence slope stability. Change dip of clay seam will influence failure surface development, but not influence slope stability. (4)Change shear strength of clay seam will influence slope stability and failure surface development. When C/R ratio is higher, failure surface will be more shallow and circular failure. When C/R ratio is lower, failure surface will be more deep and planar failure. Soften friction angle on clay seam will more sensitive than soften the cohesion on clay seam. (5)Research slope failure factors at 3.1K of the Third Freeway in Taiwan. Analysis results are now similar to actual place. Use gravity increase method by FLAC can observed the failure surface development.