| Fujian Province is located in the southeast coast of China and belongs to the subtropical monsoon climate.The climate in the province is warm and the rainfall is abundant.The rainy season occurs mostly in June.There are a large number of residual high slopes in the province.Rainfall is an important cause of slope instability.The mechanism of rainfall infiltration slope is studied and the stability of residual soil slope is monitored.The monitored deformation data is used to provide construction guidance for the slope protection project,and the slope stability is predicted based on the monitoring data to prevent the occurrence of slope landslide disasters.This paper collects the information about the mechanism and model of rainfall infiltration in the slope,The general limit equilibrium theory of slope is used to study the subject,and selects the left side slope of the A2 standard K14+260-K14+470 of the Shunshao Expressway project as an engineering example.Deep displacement deformation monitoring and surface displacement deformation monitoring were carried out to obtain deep displacement and surface displacement monitoring data and research and analysis.The numerical model of slope was established by using GEO-Studio finite element software,and the calculation scheme and hydraulic boundary conditions were designed according to the rainfall situation in the monitoring stage.Simulate the pore water pressure,soil stress and displacement during the slope monitoring stage,compare the measured data of the slope with the simulated calculation data,analyze and evaluate the accuracy of the numerical model of the slope,and analyze the slope using the numerical model.The stability changes under the condition of rainfall type,and finally the slope stability under rainfall conditions is predicted to provide landslide warning displacement for slope monitoring.The slope displacement monitoring results show that the slope displacement deformation and the cumulative rainfall are positively correlated.When the rainfall becomes larger,the actual displacement of the slope also becomes larger.The small displacement deformation of the deep slope indicates that the rainfall has little influence on the deep slope,and the large surface displacement of the slope indicates that the rainfall has a great influence on the surface stability of the slope.The measured displacement data and the numerical simulation calculation displacement are similar.The accuracy of the numerical model is relatively high,which is consistent with the actual situation.According to the numerical model,the total rainfall during the monitoring period was 1012mm,and the safety factor of the slope decreased by 20.73%.During the rainfall period,the pore water pressure and displacement of the slope soil increased with the increase of rainfall.Through the analysis of slope stability under common rainfall types,it is found that short-term heavy rain and long-term light rain have great influence on slope stability.Under short-term heavy rain and rainfall conditions,the shallow layer displacement of the slope changes greatly,and it is easy to occur in the shallow layer after rain.For landslide disasters,it is necessary to strengthen the monitoring frequency of slopes after rainfall;long-term rainwater and rainwater continue to infiltrate the soil inside the slope,which has a great influence on the deep pore water pressure and displacement of the slope,and it is easy to cause deep instabilty of the slope during rainfall.Landslides are more harmful to geological disasters.The numerical model is used to predict the horizontal displacement of the slope in the rainfall condition of the slope is 116.03mm and the vertical settlement displacement is 131.45mm.It is found that the short-time heavy rain is more accurate with the horizontal displacement warning,and the long-term light rain is more accurate with the vertical displacement.This study provides a basis for slope monitoring and forecasting and slope prevention. |
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