Test bench to assess performance of yielding steel frame supports

The implemented analysis of ground support systems in modern mines reveals the growing use of the yielding steel frame supports. This is governed by higher deformation of rock mass at great depths of the present-day mining operations. As a consequence, it has become necessary to improve the design of the yielding steel frame supports and to duly assess their basic performance: load-bearing capacity, and horizontal and vertical yield. Special bench testing of frames is the most informative technique. The governing factor here is the active loading diagram. In particular, the direction of the applied active forces should be in parallel to the longitudinal axis of the frame and should be preserved for the whole period of the frame yield testing. To observe all requirements imposed on testing the basic parameters of frames, a special test bench is developed. Its key feature is the loading mechanism using a sliding pair. In this case, the capping loading assembly placed on a slider is moved in parallel to the longitudinal axis of the frame. The slider movement is provided by a coaxially arranged cylinder. The loading assembly design allows in-plane change of the point of the force application to the frame capping. Interaction with the capping involves a pair of rollers arranged at the ends of a twoshoulder lever. The adopted design of the force application circuit of the test bench ensures the force action on the frame in the unchangeable direction independent of the capping deformation.