Study on bearing mechanical behaviour of the pre-damaged coal rock

摘要

In order to quantitatively analyze the mechanical characteristics of pre-damaged coal rocks under loads, the broken block (clusters) uniaxial compression model was established with the parallel bond model of microscopic particle flow software PFC~(2D), and the effect of pre-damaged coal-rock lumpiness, the effect of discontinuity bonding strength to bearing mechanical properties analyzed at the same time. The results show that: the pre-damaged lumpiness of coal rocks exerts a dominant effect on the bearing capacity; the discontinuity bonding strength can enhance the mechanical bearing capacity of damaged coal rocks; the ultimate strength will be influenced with little side of damaged lumpiness; and the lumpiness damages rate was less than 2% with the ultimate strength under the effect of static load. There was inverse relationship between damage rate and discontinuity bonding strength instead of the block size. The research results of this paper provide new ideas and methods for the analysis of bearing mechanical properties of coal and rock damage.