Stability Analysis And Reinforcement Study Of Liulin Senze Slope Under Rainfall Conditions

Landslide disasters are the most common geological problems in our country.There are huge economic losses owing to the landslides,and even threaten people's lives.The rainfall is the most important factor in the causing landslides.This paper takes a certain slope in Liulin County as the research object,based on the geological survey of the slope,the geological and hydrological conditions of the slope are understood,and the local meteorological data also be got to understand the local rainfall.The Geo Studio software is used to simulate the slope seepage and slope stability changes under different rainfall types,rainfall intensities and Long-term continuous rainfall.Then,the mechanism of rainfall-induced slope instability was analyzed,and the method to improve the slope stability was proposed.This article mainly draws the following conclusions:(1)Under different types of rainfall,the pore water pressure inside the slope will gradually increase with the rainfall,and the safety factor of the slope will gradually decrease with the rainfall.The pore water pressure changes the most in the upper part of the slope.From the upper part of the slope to the lower part of the slope,the increase in pore water pressure gradually decreases.In general,under each rainfall type,the pore water pressure at the upper,middle,and lower monitoring points of the slope has the same trend.The pore water pressure and the safety factor of the slope change at each moment in accordance with the rainfall at that moment.The intensity is positively correlated.In the study of the influence of four different types of rainfall on the slope,the safety factor of the slope is the smallest after the central rainfall ends.(2)Under different rainfall conditions of the slope,the rainfall intensity of 15 mm/d,30mm/d,50 mm/d,100 mm/d and 150 mm/d is simulated within 48 hours,and the rainfall is obtained.The greater the intensity,the greater the pore water pressure in the slope.When the rainfall intensity is 15 mm/d,the pore water pressure in the upper part of the slope after 48 hours of rainfall is-160 k Pa.When the rainfall intensity is 150 mm/d,the 48 hours of rainfall The pore water pressure in the upper part of the back slope is-20 k Pa,and the pore water pressure in the upper part of the slope is greatly increased.The greater the rainfall intensity,the greater the amount of rainwater that infiltrates into the slope after the same rainfall time,and the higher the water content of the soil,which causes the matrix suction of the soil to drop faster,and the corresponding shear resistance of the soil inside the slope The strength drops more,so the slope produces greater horizontal displacement in the same time under the condition of greater rainfall intensity,the slope safety factor is lower,and it is easier to lose stability.In the case of heavy rains of 100 mm/d and 150 mm/d,after 48 hours of rainfall,the slope safety factors are 0.99 and 0.94,indicating that the slope has been unstable in this case.(3)In the case of long-term continuous rainfall,the slope changes in 12 days when the rainfall intensity is 30 mm/d.It is concluded that as the rainfall time increases,the pore water pressure in the slope rises significantly,but the change is small after the 8th day,indicating that the rainfall will have a significant impact on the inside of the slope within a period of time after the start,but Afterwards,the impact on the interior of the slope is reduced.As the rainfall time increases,the safety factor decreases rapidly during the first period of rainfall,but then gradually slows down.(4)According to the simulation results,the safety factor of the slope under its own weight is 1.093,and the safety factor of the slope after 48 hours under the 150 mm/d heavy rain is 0.94.The safety factor in both cases is less than the "Landslide Prevention The safety factor of slope stability specified in the "Engineering Survey Code"(GBT32864-2016)adopts a composite support form of anchor lattice beams that can not only strengthen the deep rock and soil of the slope,but also protect the slope surface.To strengthen the slope,the reinforced slope is simulated under its own weight and 150mm/d heavy rain.The simulation results show that the safety factor of the slope has been greatly improved,and they all meet the requirements of the safety factor of slope stability in the specification.Therefore,the slope reinforcement measures are reasonable.