Studies of Failure Initiation in Unsaturated Slopes
Abstract
Mass movements, such as landslides and debris flows, are usually triggered by hydrologically driven instability of partially saturated earthen slopes and pose grave threats to life and property. Deep insight into the triggering mechanisms is vital for the prevention and mitigation of landslide hazard. This project will investigate the initiation of various failure phenomena in unsaturated earthen slopes induced by increased saturation and fluid flow through a combination of experimental modelling and numerical simulations. Small-scale slope models will be constructed, well instrumented and tested to failure in a geotechnical centrifuge. Increased saturation and fluid flow will be induced artificially by controlled sprinkling while the slope model is in flight. Numerical simulations of the centrifuge model tests will be conducted through finite element modeling using a coupled solid deformation-fluid flow formulation. To this end, a newly developed stabilized mixed hexahedral finite element employing equal order of interpolation for the displacement and pore pressure fields will be used, along with a critical-state plasticity model for the soil capable of representing compactive and dilatant plastic deformation behavior. Fluid mass is conserved globally in both the physical and numerical models because of the well defined boundary and initial conditions, thus ensuring a meaningful fluid flow analysis. The constitutive model will be calibrated with element tests on unsaturated soil used in centrifuge model. The numerical model will be validated with the centrifuge model tests.
Publikationen
Project staff
Wei Wu
Univ.Prof. Dr.Ing. Wei Wu
wei.wu@boku.ac.at
Tel: +43 1 47654-87311
Project Leader
01.08.2009 - 31.07.2014
BOKU partners
External partners
Stanford University
Prof. Ronaldo Borja
partner