Horizontal and Vertical Load Transferring Mechanisms in Longwall Roof Supports

摘要

The report describes a study that examined load transfer mechanics in longwall shield supports as part of the Bureau of Mines research program to optimize support design and utilization. The objectives of this study were to determine the contribution of the leg cylinders and the caving shield-lemniscate assembly towards full shield vertical and horizontal load resistance capability and to determine how the interaction of these members affects overall shield response. Load-displacement characteristics of the leg cylinders and the caving shield-lemniscate assembly, independent of the full shield, were evaluated from controlled displacement tests in the Bureau's mine roof simulator, and responses were compared with full shield responses to identify load transfer mechanics. It is concluded from the research that the participation of the caving shield-lemniscate assembly significantly affects the response of the shield support.