Study And Application Of Dynamic Stability Characteristics Of A Hillside Tailings Pond

Taking a tailings pond in Tangshan as the research background,aiming at the characteristics of the tailings pond,such as the stacking of multiple main dams and auxiliary dams and the fine tailings particles,this thesis selects two representative types of tailings materials（tail silt and tail silt）for static and dynamic characteristic tests,and uses the basic indoor geotechnical test to determine the basic physical properties of the two kinds of tailings materials;The static triaxial consolidation and drainage tests of two kinds of tailings are carried out,and the parameters of Duncan Chang model are obtained;The dynamic shear stress ratio and dynamic shear strength index of the two tailings are obtained by single-stage cyclic loading test;The dynamic stress-strain curve,dynamic elastic modulus and dynamic strain curve and damping ratio curve of the two kinds of tailings are obtained by multi-stage cyclic loading test.After the static and dynamic characteristic indexes of tailing silt and tailing silt are obtained,the static and dynamic stability of the tailings pond dam body are analyzed.Through numerical simulation,the nonlinear static,seepage,dynamic response,liquefaction area,permanent deformation,dynamic safety coefficient and other analysis results of the tailings pond are obtained,and finally the stability state of the tailings pond is evaluated.The conclusions are as follows:（1）The dynamic strength test shows that the stress-strain curve of tail silt is strain hardening type,and the stress-strain curve of tail silt is strain softening type.（2）The single-stage cyclic loading test of two kinds of tailings was carried out,and the dynamic shear strength indexes of the two kinds of tailings were obtained.It was found that the higher the confining pressure,the greater the consolidation ratio and the dynamic strength.（3）The multi-stage cyclic loading test of tailings samples shows that the dynamic elastic modulus of the two tailings decreases fastest before the dynamic strain is 10^-3,and decreases slowly after the dynamic strain is 10^-3;The damping ratio curve is gentle when the dynamic shear strain is 10^-5～10^-4,and becomes steeper when the dynamic shear strain is 10^-4～10^-2.（4）Through the static analysis of the tailings pond,it is found that the deformation of the accumulation dam is mainly vertical deformation,which occurs in the thickest place of the East-West ditch;When analyzing the seepage of the storage yard,it is found that under the normal working state of the seepage discharge body of the accumulation dam,the buried depth of the saturation line and the hydraulic gradient value of the tailings pond can meet the requirements,and the safety reserve is sufficient.（5）When analyzing the dynamic stability of the tailings pond,it is found that the dynamic response,liquefaction area and permanent deformation of the storage yard under the earthquake action of Elcentro wave are smaller than Taft wave and artificial wave,and the dynamic safety factor is larger than Taft wave and artificial wave.（6）Through numerical simulation,the analysis results of nonlinear static,seepage,dynamic response,liquefaction zone,permanent deformation and dynamic safety factor of tailings pond are obtained.Finally,it is concluded that the tailings pond is in a stable state under static and dynamic loads.