1. Downhill progressive landslides in long natural slopes: triggering agents and landslide phases modeled with a finite difference method
- Author
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Anders Samstad Gylland, Stig Bernander, Roland Pusch, Per-Evert Bengtsson, Lennart Elfgren, Sven Knutsson, Anders Kullingsjö, and Jan Olofsson
- Subjects
Civil engineering and architecture - Geoengineering and mining engineering ,Infrastrukturteknik ,0211 other engineering and technologies ,Defoemationsmjuknande material ,02 engineering and technology ,effects of time and rate of loading ,Geotechnical Engineering ,Infrastructure Engineering ,invalidity of one singular static load condition ,Computer software ,landslides in long natural slopes ,Geotechnical engineering ,massive spread over level ground ,Soil mechanics ,triggering agents ,021101 geological & geomatics engineering ,Civil and Structural Engineering ,021110 strategic, defence & security studies ,Finite difference method ,progressive failure in different phases ,Landslide ,Progressiva skred ,Geotechnical Engineering and Engineering Geology ,Samhällsbyggnadsteknik och arkitektur - Geoteknik och gruvteknik ,finite difference method of analysis ,Geoteknik ,Landslide mitigation ,Slope stability analysis ,Geology ,two main failure criteria - Abstract
A large landslide in Tuve (Gothenburg, Sweden 1977) initiated the development of a model for slope stability analysis taking the deformation-softening of soft sensitive clays into consideration. The model studies triggering agents and five phases in progressive slope failure are identified: (1) in-situ, (2) disturbance, (3) unstable ‘dynamic’, (4) transitory (or permanent) equilibrium, and (5) ‘global’ failure. The clay resistance in these phases may differ widely; mostly due to different rates of loading. Two time dependent failure criteria are defined: (i) the triggering load condition in the disturbance Phase (2), and (ii) the transitory equilibrium in Phase (4), indicating whether minor downhill displacements or a veritable landslide catastrophe will occur. The analysis explains why downhill landslides tend to spread over vast areas of almost horizontal ground further down-slope. The model has been applied to landslides in Scandinavia and Canada. Three case studies are briefly discussed. The model is a finite difference approach, where local downhill deformations caused by normal forces is maintained compatible with deviatory shear deformations above the potential (or the established) failure surface. Software and an easy-to-use spreadsheet are introduced as well as recent developments. See also Video Abstract. Validerad; 2016; Nivå 2; 2016-11-02 (andbra)
- Published
- 2016