open access

https://hdl.handle.net/2115/88718

A FEM-MPM hybrid coupled framework based on local shear strength method for simulating rainfall/runoff-induced landslide runout

英語

Unsaturated soil slope

2022-08

Springer

Landslides

19(8)

2021-2032

Limited by the independence and its defects of each general software package, simultaneous analysis of runoff, seepage, and large-deformation analysis is still an inevitable challenge. Generally, one of seepage, landslide-related large-deformation, and runoff is ignored or indirectly assessed during unsaturated soil landslide runout simulation. To provide a brand new solution, this paper declares a local shear strength (LSS) method to evaluate rainfall/runoff-induced reduction of the unsaturated soil shear strength. After that, a hybrid coupled hydro-mechanical framework is proposed to simulate rainfall/runoff-induced landslide runout within an unsaturated soil slope. The decrease in local shear strength corresponding to the decrease in matric suction is defined by shifting the Mohr-Coulomb (M-C) failure envelope towards compressive stress space during rainfall/runoff infiltration. Based on the proposed local shear strength method, the variable matric suction obtained from the bidirectionally coupled runoff and seepage analysis in FEM is unidirectionally transferred to the variable local shear strength for each soil material point in MPM (i.e., this is a FEM-MPM hybrid coupled model). Then, the correctness of the proposed hybrid coupled hydro-mechanical framework is effectively verified by a hypothetical homogeneous slope model. The results show that the slope stable/unstable state simulated by the proposed hybrid coupled hydro-mechanical framework has a good consistency with that simulated by the shear strength reduction technique (SSRT) and limit-equilibrium method (LEM). Afterward, combined with a case study of a natural landslide in Hokkaido, Japan, it is proved to be effective for simulating landslide runout subjected to rainfall/runoff infiltration by using the proposed hybrid coupled hydro-mechanical framework in an unsaturated soil slope.

学術雑誌論文

Accepted Manuscript

This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s10346-022-01849-z

1612-510X