Paper:

# Sensitivity Analysis of Depth-Integrated Numerical Models for Estimating Landslide Movement

## Teuku Faisal Fathani^{†}, Djoko Legono, and Muhammad Ahnaf Alfath

Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada

Jalan Grafika No. 2, Yogyakarta 55281, Indonesia

^{†}Corresponding author

Landslides are natural phenomena that occur in slopes with thick layers of weathered soil or weak geological formations. High intensity of precipitation, earthquake, and human interference can cause a huge landslide disaster. To mitigate landslide risk, an appropriate investigation to determine the stability and movement mechanisms is important to predict its potential scale. This paper proposes a sensitivity analysis of depth-integrated numerical model of landslide movement by implementing solid friction and fluid friction as the shear resistance in the constitutive systems. The hyperconcentrated solid-liquid mixture flow model and Voellmy-fluid friction model are employed in the solid friction and fluid friction mechanism, whereas the Mohr-Coulomb model is used in the solid friction mechanism. In order to analyze model characteristics and sensitivity to the inputted parameters, the parametric studies on an imaginary slope were examined. The results show that the internal friction angle among input data strongly affects the runout distance and moving velocity. The Voellmy-fluid friction model produces more lateral tendency and wider deposit in transversal directions of landslide compared to other models. The numerical model along with three constitutive equations of shear resistance was applied to the Bishamon Landslide. The hyperconcentrated solid-liquid mixture flow model and Mohr-Coulomb model yield a good agreement with the actual deposition area, whereas the Voellmy-fluid friction model produces more lateral tendency in transversal directions. The calculated runout distance reaches more than 350 m and 10.3 to 13.9 m/s of maximum velocity.

*J. Disaster Res.*, Vol.12, No.3, pp. 607-616, 2017.

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