Study On The Constitutive Model Of Coarse Grained Soil In Tailings Dam And Analysis Of The Dynamic Response

Tailings dams in our country are distributed widely,quantity,and have accidents frequently,when the accidents of tailings dams happened,it will be causing great damage on the natural environment and people’s lives and property,so the study of mechanical properties of tailings dams is particularly important.To determine the strength,the stiffness and the stability of the tailings dams in Tonglv mountain,Huangshi whether meet the requirements.Combining the indoor experiment and numerical simulation method to analyze the strength and stability.Through high pressure triaxial apparatus for soil which at the different granular composition under different confining pressure,using FLAC3 D numerical simulation software to calculate the static and dynamic result of the model,the tailings dams are calculated under different conditions respectively,the simulation including the contour of stress,the contour of displacement and the zone of state.The results are summarized as follows:1)By controlling non-uniform coefficient and the curvature coefficient to make the samples at the different granular composition,having the triaxial test that the confining pressure equaled to 0.2 MPa,0.4 MPa to 0.6 MPa,0.8 MPa,1.0 MPa,1.5 MPa and 2.0MPa for the samples which the non-uniform coefficient equaled to 5,6,7,8 and 9.Got the relationship between stress and strain of the samples,calculated the strength index of the soil samples at the different granular composition.Analyze the influence of the different granular composition and confining pressure on the relationship of stress strain and shear strength.The samples which had the bigger non-uniform coefficient,the stress-strain relation curve had higher peak and the bigger shear strength.With the increase of confining pressure in the same soil sample,the stress strain relationship is gradually changed from strain softening to strain hardening.2)Considering the traditional Duncan-chang model had advantage in calculating of earth-rock dams,and combining the data of the triaxial test,do the correction on the traditional Duncan-Zhang model,calculating the correction of Duncan-chang model parameters according to the triaxial test data,the correction model compared with traditional Duncan-chang model can describe the the tailings dams in Tonglv mountain,Huangshi’s stress-strain relationship better.3)Combined with geological exploration report,the triaxial test data and the correction Duncan-chang model,through the numerical simulation software FLAC3 D,to calculated and analyzed the dam in the gravity load,tail sand load and vertical load,seismic load’s the contour of stress,the contour of displacement the zone of state and displacement of monitoring points,fitting out the relationship between the gravity load and horizontal displacement,fitting out the relationship between the gravity load and vertical displacement;Through analyzing the state and combining with the displacement of the monitoring point,fitting out the relationship between the horizontal displacement and vertical displacement of the dam under the load of tailing sand and the vertical load.By input the acceleration of the earthquake to the model of the dam.Analyzed the response of the displacement and the acceleration from different monitoring points,achieved the amplification law of acceleration and displacement from the monitoring point.The results of this research can analyze the mechanical characteristics of the tailings dam accurately,and have great guiding significance for practical engineering.