An Investigation of Shear Strength Parameters for Layer Interfaces

• Main Authors: Ying-hao Wu, 吳穎顥
• Other Authors: Ze-shan Syu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/42858485967162578521

碩士 === 逢甲大學 === 土木工程學系 === 101 === Taiwan is located in the Pacific Rim seismic belt with obvious displaced landform characteristics of slope fault zones such that slopes near construction projects of roads, bridges, tunnels and dams are under frequent impacts of disasters such as landslide and debris flow during normal time, earthquake, or torrential rain. For slopes with obvious displaced landform characteristics of fault zone, landslides are often resulted from the delamination sliding failure of layered soil such that the shear strength parameters adopted by slope stability analysis should be obtained from the shear test of sliding failure along the layer interface. However, as indicated by numerous cases of large scale delamination sliding failures, it can be found during the design analysis prior to sliding failure or even the investigation of disaster cause after the sliding failure that the shear strength parameters adopted by slope stability analysis are obtained from the result of shear test of sliding failure penetrating through a specific soil mass. For piles of debris fallen into the wild creek and river valley, the result of shear test of sliding failure penetrating through certain soil mass has also been widely adopted by current literatures to develop the mechanism of debris flow. Therefore, such inconsistency with actual condition has led to rather diversified mechanisms of debris flow. For improving aforementioned issue, in this dissertation the landslide disasters that took place in Lincoln Residence and 3.1km at National Highway No. 3 have been used as the examples for in-depth investigation of the use of interface shear strength parameters to effectively define the in-situ landslide failure behavior in the slope stability analysis after delamination sliding failure with test conditions consistent with the in-situ conditions. In this dissertation an attempt has also been made to use the principle for debris to suspend when bottom velocity Vb (or hydraulic gradient i) is greater than its critical value. Such a new concept is helpful to unify the academic problem of disputes over debris flow mechanisms.