Study On Prediction And Countermeasure Of Expressway Subgrade Disease Caused By Rainfall

With the rapid development of China’s economy,China’s highway industry is also constantly developing.However,with the rapid development of expressway construction,the roadbed disease problem is becoming more and more serious.Especially the roadbed disease caused by rainfall,it caused a deep degree of damage and a wide range of impact.In this paper,based on unsaturated soil theory,the failure mechanism of roadbed diseases under rainfall condition is studied,furthermore,the prediction model for the prediction of the disease of roadbed is established,and the measures for prevention and cure of roadbed diseases are put forward.This paper mainly from the following aspects:(1)Summarized the types and characteristics of expressway subgrade diseases under rainfall conditions,including the embankment slope instability,slope instability,collapse and subsidence of roadbed,roadbed protection facilities damage and destruction of the debris flow;(2)The mechanical properties of unsaturated soils are analyzed from the aspects of seepage characteristics,strength theory and suction characteristics,based on the basic equation of unsaturated seepage and the approximate solution of rainfall infiltration,the infiltration process and mechanism of subgrade slope under rainfall condition were studied;(3)By using the simplified Bishop method,the simplified Janbu method and the generalized limit equilibrium method,and considering the influence of matrix suction,The stability of subgrade under rainfall condition is analyzed,the mechanism of the effect was also studied;(4)By using Geo-Studio software to simulate the rainfall infiltration of highway subgrade slope,the stability of subgrade slope under different rainfall conditions is studied;(5)Established the model for predicting and forecasting the disease of roadbed,using the daily rainfall as the forecast and early warning criterion,selected subgradeslope of ZhangZhuo Expressway and Xingfen highway to predict the disease of landslide,collapse and debris flow,it also puts forward the measures of prevention and cure of roadbed diseases caused by rainfall.