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Abstract

Field investigations in debris flow source areas reveal that granite is exposed on slope surfaces, while a thin layer of sandy, weathered residual soil is distributed at the slope tops. This paper focuses on the significant permeability differences between the slope base and the upper weathered soil layer. A full-scale slope model experiment was conducted to replicate these characteristics, including rainfall infiltration simulations under both exposed surface conditions and conditions with non-woven fabric filter mats applied. The aim was to investigate the failure mechanism of rainfall-induced debris flows. The results show that the primary trigger for debris flows is the presence of a highly permeable coarse-grained layer between the sandy soil layer and the impermeable soil layer. This coarse-grained layer facilitates groundwater infiltration and interlayer flow, causing a rapid increase in pore water pressure and leading to soil liquefaction phenomena. The paper confirms the effectiveness of non-woven fabric filter mats in inhibiting infiltration during rainfall events.

Publication Date

5-11-2023

DOI

10.14048/j.issn.1671-2579.2023.02.008

First Page

43

Last Page

50

Submission Date

March 2025

Reference

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