Abstract
Problem statement: A number of tailings earthen dams have failed during past earthquakes. The failure of tailings dam ultimately results into the release of the stored tailings waste deposit in the surrounding locality. To reduce such damage of tailings earthen dam, a detail method of seismic analysis is very much essential which can be used reliably for the design and construction. Approach: To establish a detail method of static and seismic analysis for a tailings earthen dam, in this study both the static and seismic analysis were performed for a typical section of tailings earthen dam. The whole analysis was performed using various software packages like FLAC3D, TALREN 4, SEEP/W and SLOPE/W. Results: After FLAC3D analysis it was observed that under the seismic loading condition the maximum displacement of the dam is about 66.7 cm, whereas by using the Makdisi-Seed method the maximum displacement was obtained as 57 cm. FLAC3D analysis showed that the base level input acceleration gets amplified with the height of the dam and at the crest level the amplification is about three times. After slope stability analysis under seismic loading it was found that the factor of safety is 0.89, but under the static loading condition the minimum value of factor of safety was obtained as 1.22. Conclusion/Recommendation: From this analysis it was clear that the dam was unsafe under the seismic loading.
Highlights
As per ICOLD[6] several tailings earthen dams have failed during past earthquakes
The phreatic surface obtained from the FLAC3D seepage analysis showed very good similarity with the phreatic surface developed in SEEP/W analysis
From the results of the seepage analysis it can be concluded that the finite difference method based FLAC3D and finite element method based SEEP/W give similar results
Summary
The failure of tailings dam results into the release of the stored tailings waste deposit which often fairly dangerous because of the level of toxicity or corrosivity or both to human life and other living beings. To reduce such damage of tailings earthen dam, a detail method of seismic analysis is very much essential which can be used reliably for the design and construction. From the literature review it is found that since the beginning of 1920s and up to 1960s ‘Pseudo-static method’ of analysis is most popular This method is too much simple and it dose not take into account the nature of the slope-forming material or the foundation material. Gazetas[3] proposed an improved ‘Inhomogeneous shear beam model’ which can take care of the fact that the shear modulus in earth or rock-fill dams is not constant but increases with 2/3power of depth from the crest
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
