This report summarizes the results from the subsidence research study completed by the U.S. Bureau of Mines at the Roadside Mine, Powderhorn Coal Co., Palisade, Co. This research was conducted from February 1981 to August 1985, with additional data obtained during July 1991, to evaluate residual subsidence. The Bureau studied subsidence at three district room-and-pillar sections at separate locations over the mine and determined the maximum subsidence values and surface subsidence profiles for each mining section. Maximum subsidence of 3.0 ft occurred over the room-andpillar sections, with overburden depths ranging from 50 to 600 ft. Surface tension cracks had occurred, and were still evident during the residual subsidence survey.

Underground coal mining disturbs both the overburden strata and the immediate floor strata. The subject of surface subsidence deals with the issues associated with the movement of overburden strata, which are the layers from the seam to the surface, where structures and water resources important to human activities are located. Surface Subsidence Engineering provides comprehensive coverage of the major issues associated with surface subsidence. The chapters are written by experts on surface subsidence in the three leading coal producing and consuming countries in the world: Australia, China and the United States. They discuss general features and terminologies, subsidence prediction, subsidence measurement techniques, subsidence impact on water bodies, subsidence damage, mitigation and control, and subsidence on abandoned coal mines. In addition, the final chapter addresses some of the unique features of surface subsidence found in Australian coal mines. The book provides information on coal seams ranging from flat to gently inclined to steep to ultra-steep seams. Written for mining engineers, geotechnical engineers and students of mining engineering, this book covers both theories and practices of surface subsidence. Unlike previous publications, it also deals with the subsidence impact on surface and groundwater bodies, crucial resources that are often neglected by subsidence researchers.

The best of ground control technology, 40 years in the making. Developments in Ground Control summarizes the objectives, methodology used, and major conclusions reached from papers presented and published in the International Conference on Ground Control in Mining (ICGCM) proceedings from 1981 to 2020. Because the subject areas of the papers published in the proceedings are so broad, ranging from accident training and coal/rock bursts to geology, pillar, multiseam mining, in situ stresses, roof falls, and roof supports to surface subsidence, the papers were grouped into 13 aggregate topics and addressed separately in 13 book chapters by 13 authors from 4 countries. These book chapters are a fresh look at the topics, providing new insights, sourcing older papers, and summarizing data. This is an enormous help for those seeking information on ground control. There were 1,795 papers in the 40 years of ICGCM proceedings in more than 40 ground control topical areas. It would certainly be very time consuming if not impossible to find the right papers of interest in a timely manner. This book makes it easy for interested people to find the progress, application, and achievements of certain techniques from the past 40 years and how they affected the field of ground control and the world mining industry, in particular, the United States. Generally speaking, most researchers tend to favor recent developments when performing a literature search, ignoring or considering old papers outdated. In contrast, over the last 40 years, most research findings for a specific topic in ICGCM received continuing attention for subsequent development or repeated citations if applications were successful.