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Strip mining for coal reserves has been and will continue to be a cost effective means of obtaining energy sources for the needs of the United States. A byproduct of strip mining is thousands of acres of relatively flat land created by placing the spoil material in valleys and over previously mined benches. These mine spoil fills offer an opportunity to build large developments and industrial facilities. However, due to the many unknowns associated with the performance of mine spoil fills there is reluctance to invest large sums of money into a mine spoil fill site due to the risk of detrimental settlement. This paper discusses research conducted on two previously mined sites that are currently being developed into industrial parks. The sites were strip mined using mountain top removal and contour mining methods. The mine spoil was placed using end dumping methods. End dumping consists of using dump trucks and scrapers to remove the spoil from the mining area and hauling it to the disposal areas. The purpose of the research on the two sites was to develop a reasonable predictive model to evaluate the future settlement of the mine spoil fill. Settlements were monitored using surface monuments and extensometers located throughout the site. The extensometers were monitored for five years. The results of the settlement monitoring indicated that on end dumped mine spoil fill sites which are less than 100 feet (30m) thick and over 10 years old, large settlements associated primary compression of the fills have stopped and the fill is in a secondary compression phase. Future additional settlements due to secondary compression were found to be less than 1 inch (2.5 cm) over the five year monitoring period. This research resulted in developing a predictive settlement model that will assist in understanding the settlement characteristics of similar mine spoil fill sites. This model will result in less conservative site development options, providing cost savings without increasing the risk of detrimental settlements when building on end dumped mine spoil fill sites.

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