Research On The Stability Of Granite Cutting Slope In Jiangmen Area Of Guangdong Province By Rainfall

Guangdong province southwest,mostly granite geology,belongs to the subtropical and tropical monsoon climate,due to the geographical environment is more mountainous landform,and has the characteristics of diversity of mountain climate,long summer without winter,generally concentrated in the rainy season from April to September each year,the inclusions during the typhoon,the rainfall is abundant,and rainfall is natural landslide is the most fundamental factors,only in 2019 in guangdong province occurs in early June 3 cause landslide events caused by rainfall,high slope instability caused by rainfall in the region of research is urgently needed.This paper used crawler technology to obtain nearly 70 years of historical rainfall data in jiangmen area,made a statistical analysis of its historical rainfall,obtained the rainfall intensity,duration and overall distribution in this area,and obtained the once-in-a-century characteristic rainfall parameters,used for slope stability analysis.Combined with the landslide accident in yangchun city in 2019,the pre-rainfall analysis was carried out to obtain the double rainfall threshold of the landslide in jiangmen area,and according to the distribution law of historical rainfall,the critical protection period of slope protection construction before the rainy season was proposed to provide Suggestions for construction units.The rainfall conditions that need to be studied were determined,and the soil performance test after rain was conducted on the slope soil to obtain the moisture content of each soil layer under different rainfall conditions,and the shear test was conducted to obtain the shear strength parameters of each soil layer under the corresponding moisture content.Geo-studio finite element software was used to conduct numerical simulation of the slope,check and evaluate the design parameters,study the seepage stability of the slope under the characteristic rainfall parameters,and calculate the slope safety coefficient under different working conditions by using the strength reduction principle.By monitoring the surface displacement and deep displacement of the slope and combining with the rainfall during themonitoring period,the changes of the displacement before and after the rainy season and the protection were analyzed to evaluate the stability of the slope.Combined with the proposed double rainfall threshold,an early warning system for landslide in jiangmen area is established,which can give early warning for weather conditions in the next 7 days,optimize monitoring frequency on the basis of ensuring the safety of slope,and provide reference for monitoring units.