Dissipative structure suppression as a way to increase the sustainable improvement of the frame support bearing capacity

Abstract

Introduction. A yield frame support is a basic means of providing the underground roadways’ stability in the deep mines operating in the hard ground control condition when the ratio of the ground pressure to the unconfined strength of surrounding rock mass exceeds 0.33. The operators adjust the nominal bearing capacity of the frames at 0.55 of their maximum or peak resistance Fmax because the frames operate in a dry friction mode spontaneously generating oscillation, which causes variation of the resistance in the range from 0.1 up to 0.9 of Fmax . Aim/tasks. We intended to reduce the dynamic oscillation of the support resistance that allows for increasing their bearing capacity. Methodology. We used a computer simulation by FLA3D model, indoor testing of the frames, and actual measurements in an underground coal mine. Results. We revealed a specific behavior of the frame support that reduced the limit of the bearing capacity by 45%. During yielding, the frames generate dissipative structures (DS) that become apparent due to the dynamic nature of stick-slip friction following the yielding process. We demonstrated that DS control and especially its suppression provides a sustainable increase in the frame bearing capacity. Conclusions. Improvement of the yield frames design and especially their clamps are the prospective way to control DS and provide sustainable enhancement of the frame bearing capacity.