Strength behavior of slip-zone soils of landslide subject to the change of water content

• Published in: Natural hazards (Dordrecht) Vol. 68; no. 2; pp. 711 - 721
• Main Authors: Nian, Ting-Kai, Feng, Zhong-Kai, Yu, Peng-Cheng, Wu, Hui-Jun
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.09.2013; Springer; Springer Nature B.V
• Subjects: Civil Engineering; Clay; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Earthquakes; Engineering and environment geology. Geothermics; Environmental Management; Exact sciences and technology; Excavation; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Landslides; Landslides & mudslides; Moisture content; Natural Hazards; Natural hazards: prediction, damages, etc; Original Paper; Physical properties; Property; Rainfall; Reservoirs; Seismic activity; Shear; Shear strength; Shear stress; Slope stability; Soil mechanics; Soils; Strain; Strength; Water; Water content; Water levels; China; Landslide; Slip-zone soil; Shear strength behavior; Soil mechanics; Water content; strain; shear strength; rainfall; strength; reservoirs; excavations; loading; earthquakes; mechanical properties; rupture; shear stress; soil mechanics; landslides; water content; cohesion; friction angles; Natural hazards; soils
• DOI: 10.1007/s11069-013-0647-5
• ISSN: 0921-030X

Landslides are the major natural hazards in many countries all over the world and are usually caused by heavy rainfall, water level change of reservoir, excavation, earthquake, etc. Whether the landslide occurs or not in rainfall season, the strength variation of slip-zone soils of landslide is regarded as the vital control factor. Thus, strength behavior for slip-zone soils of landslide subject to the change of water content is required to be evaluated in a potential landslide area. In this paper, the shear strength of typical slip-zone soil, six groups of 25 specimens of remolded clay samples from Daxishan reservoir landslide, was systemically investigated using the improved direct shear test apparatus in order to fully understand its physical and mechanical properties, and also the shear and failure behavior. Furthermore, the fitting equations for expressing the relationship between the shear strength (effective cohesion and internal friction angle) and vertical loadings, initial water contents of slip-zone clay were established based on the experimental results. In particular, a series of shear stress–shear strain curves under various vertical loadings and different water contents were observed. The results show that a “softening” stress–strain behavior is achieved for unsaturated slip-zone soil, while a “hardening” curve is found for saturated slip-zone soil.