Laserfiche WebLink
•• it <br />Bond Release Area D-Aline lk3 <br />December 5, 1980 <br />Page Two <br />No problems are anticipated with respect to slope stability. It is <br />my opinion that the cracks are a result of differential settling only <br />and that there has been and will be no horizontal or rotational <br />movement. This opinion is based upon the following: 1) the correla- <br />tion of the cracks with the final highwall and the high probability <br />for differential settling in the condition depicted on the cross- <br />section; 2) the low angle of surface slope (approximately 3.6 to 1, <br />or 28% maximum grade, as shown on the cross-section); 3) the highly <br />angular nature of the spoil material which prevents or retards move- <br />ment along any possible slippage planes; and 4) the fact that the <br />spoil mass is resting on the floor of the old mine which is extremely <br />stable and dips towards the spoil mass a[ approximately 27 percent. <br />As can be seen on the cross-section, the acute angle formed between <br />the final highwall and the pit floor provides a configuration which <br />will prevent any significant horizontal mass movement of spoil. <br />Based upon our experience at other locations, virtually all of the <br />settling phenomenon occurs within the first two to three years after <br />backEilling. I would expect that we will experience little or no <br />additional compaction of the spoils and that normal sediment trans- <br />port will soon fill the cracks with soil. <br />G4M/lar <br />cc: JTCooper, JMGrlffin <br />~~ <br />