Direct Shear Test Of Earth-rock Filler And Stability Analysis Of High-filled Embankment Under Rainfall Condition

Naturally formed or artificially backfilled high earth rock embankment fillers can be seen everywhere in our country,while landslides and other disasters can easily occur in the natural environment or under human influence.Therefore,this project took the Zunhua to Qinhuangdao section of Beijing-Qinhuangdao expressway as the research object.From the perspective of shear characteristics,this paper analyzed the influence of rock content and saturation on the properties of earth rock mixture filler,and discussed the stability of earth rock fill slope under rainstorm and Extreme Rainstorm by using simulation software.The large-scale direct shear test was carried out in laboratory.The rock content and saturation were taken as single variables to analyze and discuss the shear characteristics of earth rock fill under different normal stresses.The influence of rock content and saturation on the shear failure mode of earth rock fill was summarized.It is found that with the increase of stone content,the apparent cohesion and internal friction angle first increase and then decrease,while with the increase of saturation,the apparent cohesion decreases,and the internal friction angle decreases first and then increases.With the help of the theory of unsaturated seepage,the FLAC3 D software was redeveloped by using FISH language.The permeability coefficient and seepage boundary are modified.The unsaturated seepage analysis module was developed by Mohr Coulomb strength theory.The infiltration amount of each seepage time step was updated by using geometry command,and the rainfall infiltration module was developed.Based on the engineering design drawings,the 3D modeling software Rhino and FLAC3 D were used to establish the 3D calculation model of high fill earth rock embankment,and then the test parameters were input into the model to analyze the stability of high fill embankment slope under rainstorm and Extreme Rainstorm conditions.The relationship between rainfall infiltration depth,the development of saturated area and rainfall time was summarized.The failure mechanism and failure mode of earth rock fill slope under two working conditions were obtained.