Study of the dynamic stability of tailings dam based on time-history analysis method
WANG Wensong
YIN Guangzhi
WEI Zuoan
ZHANG Qiangui
CAO Guansen
JIN Xiaofei
Abstract：The dynamic response and slope stability of Dashahe tailings dam in southern China during earthquake was studied for the scenarios before and after dam raise.Dynamic triaxial tests were carried out to obtain the dynamic shear strength,shear modulus,and damp ratio of three different tailings samples,namely,fine sand,silty sand,and silt.Numerical analyses were then conducted to determine the extent of liquefaction zone,factor of safety of the dam,and subsidence of the dam crest,using time-history analysis,shear stress contrast,finite element limit equilibrium,and softening modulus method.In addition,the limitations of conventional limit equilibrium methods were discussed.The results show:1) dynamic shear stress ratio of the tailings decreases with the increase of confining pressure due to dam raise,and dynamic pore water pressure ratio at failure increases with the increase of loading cycles;2) Liquefaction mainly occurs at shallow depth underneath tailings pond both before and after dam raise,provided effective drainage system is in-place;3) Permanent deformation takes place in the form of subsidence in upper part of the dam and toe extrusion at the lower part.The subsidence of the dam crest increases with the dam raise.Nevertheless,the Dashahe railings dam still meets Chinese tailings dam safety standards under design earthquake load.
Keywords：tailings damdynamic stabilitytime-history analysisdynamic triaxial testliquefactionseismic subsidence
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 271-279 )