Characteristics of preferential flow suffosion of soil-rock interface in spherical weathered granite slopes

Authors

Hong qiang DOU, Zijin School of Geoloy and Mining, Fuzhou University, Fuzhou, Fujian 350108, China; Fujian Key Laboratory of Geohazard Prevention, Geological Engineering Survey in Fujian Province, Fuzhou, Fujian 350002, China; Key Laboratory of Geohazard Prevention of Hilly Mountains, Ministry of Natural Resources, Geological Engineering Survey in Fujian Province, Fuzhou, Fujian 350002, ChinaFollow
Sen hua XIE, Zi jin School of Geoloy and Mining, Fuzhou University, Fuzhou, Fujian 350108, China
Wen bin JIAN, Zijin School of Geoloy and Mining, Fuzhou University, Fuzhou, Fujian 350108, China; Fujian Key Laboratory of Geohazard Prevention, Geological Engineering Survey in Fujian Province, Fuzhou, Fujian 350002, China; Key Laboratory of Geohazard Prevention of Hilly Mountains, Ministry of Natural Resources, Geological Engineering Survey in Fujian Province, Fuzhou, Fujian 350002, ChinaFollow
Hao WANG, Zijin School of Geoloy and Mining, Fuzhou University, Fuzhou, Fujian 350108, China; Fujian Key Laboratory of Geohazard Prevention, Geological Engineering Survey in Fujian Province, Fuzhou, Fujian 350002, China; Key Laboratory of Geohazard Prevention of Hilly Mountains, Ministry of Natural Resources, Geological Engineering Survey in Fujian Province, Fuzhou, Fujian 350002, China
Chao xu GUO, Fujian Key Laboratory of Geohazard Prevention, Geological Engineering Survey in Fujian Province, Fuzhou, Fujian 350002, China; Key Laboratory of Geohazard Prevention of Hilly Mountains, Ministry of Natural Resources, Geological Engineering Survey in Fujian Province, Fuzhou, Fujian 350002, China

Corresponding Author

JIAN Wen bin

Abstract

Due to rainfall, the soil rock differential weathering interface of spherical weathered granite soil slopes is prone to evolve into a preferential seepage channel and undergo seepage induced suffosion, which accelerates the deformation and instability of these slopes. However, little research has been carried out on the characteristics of seepage induced suffosion and the migration of fine particles. Based on the u nsaturated seepage theory of porous media, a numerical calculation framework is established to accurately describe the seepage induced suffosion process at the soil rock interface, considering the coupling relationship between the fine particle migration, suffosion initiation response and unsaturated seepage. The finite element method is used to construct a seepage induced suffosion model for unsaturated granite residual soil under the effect of preferential flow. Based on the seepage induced suffosion proc ess of homogeneous soil columns, the suffosion characteristics of preferential flow under three typical soil rock interface burial states are systematically investigated. The results show that the soil rock interface and the matrix permeability of spherical weathered granite soil slopes are highly variable, with the wetting front forming a downward depression infiltration funnel, and the degree of depression of the wetting front becomes more pronounced as rainfall continues. The degree of fine particle loss is related to the burial state of the soil rock interface, in which the preferential flow potential suffosion of the under filled soil condition is the most significant, and even excess pore water pressure occurs at the interface, which is the most unfavo rable to the stability of this type of slope. The research results can provide a scientific basis for accurately evaluating the stability of spherical weathered granite soil slopes under rainfall conditions.

Graphic Abstract

Recommended Citation

DOU, Hong qiang; XIE, Sen hua; JIAN, Wen bin; WANG, Hao; and GUO, Chao xu (2024) "Characteristics of preferential flow suffosion of soil-rock interface in spherical weathered granite slopes," Rock and Soil Mechanics: Vol. 45: Iss. 4, Article 2.
DOI: 10.16285/j.rsm.2023.5644
Available at: https://rocksoilmech.researchcommons.org/journal/vol45/iss4/2