Failure of a landslide dam might occur by river discharge or rainfall. A rise of the upstream water level of a landslide dam and rain infiltration into the dam body increase pore water pressure and the weight of the dam. In this study, transient seepage analysis of rainfall infiltration and dam stability analysis are performed. A two-phase flow simulation using the FLAC finite difference code is adopted to analyze unsaturated seepage flow in transient fluid-mechanical calculations. The safety factor of dam stability is evaluated using the shear strength reduction technique. The parameters discussed in this study include the rising speed of the water level, rain infiltration, and the hydraulic conductivity of soil. The results show that the time to slope failure of the dam is approximately 247 min when only the effect of the rising upstream water level of the dam is considered. The failure time decreases to 189 min when the rain infiltration and rising upstream water level of the dam are considered. The results also indicate that the hydraulic conductivity of the dam affects dam failure time.

Geosynthetics such as geogrid or geotextile are often used for the reinforcement of weak soils. A lot of research has been performed to investigate the bearing capacity of reinforced shallow foundations using limit equilibrium method with Mohr-Coulomb failure criterion. In this paper, the loading behavior of reinforced strip footings was studied numerically using a commercial Finite Difference program with a Double-Yield soil model. First, the load-settlement curve of an unreinforced strip footing was simulated using both Mohr-Coulomb failure criterion and the Double-Yield model. The simulated bearing capacities were then compared with Terzaghi's solution. The effects of various parameters, such as burial depth and length of the reinforcement, as well as arrangement of two reinforcement layers were also studied. Results of this study indicate that the loading behavior of strip footings simulated with the Double-Yield model is more realistic and the Manuscript Click here to download Manuscript: ASCE-IJG manuscript_revision 3.docx 2 optimum burial depth and length of reinforcement obtained from this study also agree with values reported by previous investigators.

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