Source
Best Practices in Rock Engineering, Proceedings of the Third Southern African Rock Engineering Symposium, 10 - 12 October, 2005, SARES 2005. Johannesburg, Republic of South Africa: South African Institute of Mining and Metallurgy, 2005 Oct; :301-334
Abstract
Many of the support concepts currently used in the United States originated in the Republic of South Africa. These products include the Hercules Crib, Propsetter, MX Prop, Rocprop, and Spider Prop. Another recent development has been the introduction of hydraulic prestressing units, such as the Jackpot system, to various U.S. standing support systems. Several other prop-type supports with similarities to systems used in South Africa are in use in U.S. coal mines. Some exciting new developments that improve the installation and yield performance of props are also underway. In addition to prop-type supports, crib-type supports and single-unit systems such as the Can support are also often used in U.S. longwall tailgates. The goal in U.S. support development is to enhance roof support capability while alleviating material-handling barriers in order to reduce injuries associated with support handling and installation. Support products are generally full-scale tested in NIOSH's unique Mine Roof Simulator load frame. The performance testing protocol is designed to simulate the full range of load conditions that occur in underground mining in order to identify the performance deficiencies and limitations of the support products. Once the products complete the performance evaluation, they are implemented into the NIOSH-developed Support Technology Optimization Program (STOP). STOP is a Window's-based software program for facilitating the design of standing roof support systems. STOP has become an industry standard for comparing performance capabilities and facilitating the application of support products into various mining conditions. This paper provides an overview of the support design and application philosophy in the United States.