Analysis of the Relationship Between Stability of Fully Weathered Granite Landslides and Rainfall
Rainfall is the primary trigger for landslides.With China's disaster prevention efforts chang-ing from post-disaster relief to pre-disaster prevention,and from disaster loss reduction to disaster risk mitigation,it is crucial to understand the triggering mechanisms for rainfall-induced disasters and es-tablish effective early warning systems for geological disaster prevention and mitigation.To address the stability issues of rainfall-induced landslides in fully weathered granites,shear tests on in-situ soils with different moisture contents and large-scale physical similarity model tests were carried out in Qin-gdao's Lao Mountain area as an example.The slope's response to rainfall was revealed,the relation-ship between the stability of fully weathered granite landslides and rainfall was explored,and relevant quantitative formulas were fitted.Additionally,ABAQUS was used to establish a three-dimensional flow-solid coupled numerical model for the slope,validating the equations through the strength reduc-tion method.The research results showed that:(1)Rainfall-induced fully weathered granite landslides failure progressed through four stages:infiltration and erosion → surface deformation → damage deep-ening → overall instability.The slope exhibited the phenomena of"drum-like bulge"and"sheet-like slipping"during the deformation period,and ended up with a translational slipping.(2)The slope's re-sponse to rainfall infiltration showed spatial variability,with greater rainfall intensity leading to faster increases in moisture content and pore pressure.(3)Based on the experimental results,formulas de-scribing the relationship between landslide moisture content,safety factors,and rainfall intensity and duration were derived.Numerical simulation confirmed the accuracy of these formulas with minor devi-ation,accurately describing the quantitative relationship between landslide stability and rainfall.The results of the study provide insights on early warning and prevention strategies for landslides in areas with similar strongly to fully weathered granite.
fully weathered graniterainfall-induced landslidesphysical model testsnumerical simula-tionquantitative studies