Effective stress analysis method of seismic response for high tailings dam

Abstract

Based on the analysis method for tailings dam in upstream raising method presently used in metallurgy and nonferrous metals tailings depository in the world, an effective stress analysis method of seismic response for high tailings dam was developed according to the results of engineering geological exploration, static and dynamic test and stability analysis on Baizhishan tailing dam 113.5 m high. The law of generation, diffusion and dissipation of seismic pore water pressure during and after earthquake was investigated, and the results of tailings dam’s acceleration, seismic dynamic stress and pore water pressure were obtained. The results show that the seismic stability and liquefaction resistance of high tailings dam are strengthened remarkably, and the scope and depth of liquefaction area at the top of dam are reduced greatly. The interior stress is compressive stress, the stress level of every element is less than 1.0 and the safety coefficient of every element is greater than 1.0. The safety coefficient against liquefaction of every element of tailing dam is greater than 1.5 according to the effective stress analysis of seismic response by finite element method. The calculated results prove that liquefaction is the main reason of seismic failure of high tailing dams, and the effect of seismic inertia forces on high tailing dams’ stability during earthquake is secondary reason.

Keywords

tailings dam / seismic response / effective stress / nonlinear analysis / against liquefaction / upstream raising method

References

[1] LiuH.-x., LiN., LiaoX., et al.. A new technique of combining accretion by cyclone separator and scattertube for tailings dams[J]. Journal of Central South University of Technology, 2004, 11(2): 185-191

[2] DobryR., AlvarzeL.. Seismic failure of Chilean tailings dams[J]. Journal of Soil Mechanics and Foundation, 1967, 93(5): 83-108

[3] ZhouL.-xia.. Accidents of some tailings dams abroad: causes and lessons[J]. Journal of Mining and Metallurgical Engineering, 1990, 10(2): 64-66

[4] Tailing Dam Safety Investigation Group of Ministry of Metallurgy.Investigation report about safety stability of tailings dams in China[R], 1987, Beijing, Ministry of Metallurgy

[5] StevenG. V.Planning, Design and Analysis of Tailings Dams[M], 1983, New York, Wiley-Interscience Publication

[6] MoL.-s., WangZ.-p., ChenS.-r., et al.ZBJ1-90 design specification of the tailings[S], 1991, Beijing, China Plan Press

[7] LiuH.-xiang.A Study of the Nonlinear Seismic Response Analysis of High Tailings or Earth Dams by FEM [D], 1993, Changsha, Changsha Research Institute of Mining and Metallurgy

[8] ShengS.-pan.SL237-1999 specification of soil test[S], 1999, Beijing, China Hydraulic Press

[9] CividiniA., GiodaG.. Finite-element approach to the erosion and transport of fine particles in granular soils[J]. International Journal of Geomechanics, ASCE, 2004, 4(3): 191-198

[10] MejiaL. H., SeedH. B.. Comparison of 2D and 3D dynamic analyses of earth dams[J]. Journal of the Geotechnical Engineering, ASCE, 1983, 109(11): 1383-1398

[11] HongY.-kang.Foundation Soil Science and Soil Mechanics[M], 2000, Beijing, The People’s Communication Press

[12] WenS.-p., QiuJ.-k., LiuH.-xiang.. Optimization of the new process for highly-constructing of subdam and comprehensive measures for flood prevention of Xishimen Iron Mine’s tailings pond[J]. Journal of Mining and Metallurgical Engineering, 1997, 17(3): 1-5

[13] ZhouJ., XuZ. Y.. 3-D dynamic effective stress analysis of earth/tailings dams[C]. Int Symposium on Environmental Geotechnology, 1986, Berkeley, California University Press

[14] WuA.-x., SunY.-z., LiQ.-song.. Self-organized criticality of liquefaction in saturated granules[J]. Trans Nonferrous Met Soc China, 2003, 13(1): 180-183

[15] BromheadE. N.The Stability of Slopes[M], 1986, New York, Surrey University Press

[16] WuA.-x., GuD.-s., SunY.-z., et al.. Experiment and mechanism of vibration liquefaction and compacting of saturated bulk solid[J]. Journal of Central South University of Technology, 2001, 8(1): 34-39