NIOSHTIC-2 Publications Search
Design of permanent block stopping to resist strata convergence.
Ray-RE Jr.; Stephenson-JW; Berry-JA; Timko-RJ
Min Eng 1985 Nov; 37(11):1308-1312
Conventional concrete block plastered with a cementitious coating is the most common material used in the construction of permanent stoppings to direct airflow in underground mines in the US. All mines experience various degrees of strata convergence depending on depth of overburden, geological conditions, and type of roof support employed. Strata convergence will cause cracks and joint openings in masonry stoppings, resulting in significant air leakage losses. Where strata convergence is severe, complete structural failure of the stopping can ultimately occur. Reconstruction of damaged or destroyed stopping adds expensive overhead to mining operations, and even greater expenses are incurred from the additional fan horsepower required to overcome leakage losses. Ideally, a stopping should maintain high resistance to airflow while yielding to strata convergence. By properly incorporating a polyisocyanurate rigid foam material within the masonry block structure, stopping service life can be increased in mines experiencing strata convergence problems such as floor heave, roof loading, and lateral rib movement.
Structural-analysis; Underground-miners; Underground-mining; Mine-workers; Mineral-processing; Mining-industry; Mining-equipment
OP; Journal Article
Issue of Publication
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division