Centrifugal Model Analysis of Coal Waste Embankment Stability.
Townsend-FC; Goodings-DJ; Schofield-AN; Al-hussaini-MM
NTIS: PB/81-194524 :118 pages
Centrifugal model embankments with varying geometries and materials were constructed of coal waste material, accelerated from 100 to 120 times earth's gravity, and subjected to various throughflow rates until failure occurred. Complementary laboratory tests were performed on the waste materials to obtain strength and permeability parameters for analytical calculations to predict observed centrifugal model behavior. Failures in the form of deep-seated failure, or erosion and sediment transport or a combination of both, occurred in model embankments with IV:1-1/2h and IV:2h slopes when the phreatic surface due to seepage exited on the downstream slope. Positive seepage control, that is, a toe drain, successfully prevented sloughing and failures. Slope stability analyses agreed conservatively well with observed model performance. Factors of safety ranged from 0.7 to 1.02 At the instant of failure for models with retrogressing slips as compared with 1.05 to 1.7 For stable embankments. These models verified existing criteria of a minimum safety factor of 1.3 and the necessity of positive seepage control. Research done under Contract No. H0282018 by U.S. Army Engineer Waterways Experiment Station. Available for reference at Bureau of Mines facilities.
CP; Final Contract Report;
NTIS Accession No.
U.S. Army Eng. Waterways Ex. St.