Study on the Coal Seam Dynamic Damage Evolution during Coal Seam Pulse Water Infusion

Abstract

There is a strong fluid-solid coupling effect during the process of coal seam pulse water infusion. Based on the basic principle of liquid-solid coupling, the dynamic damage evolution rule during coal seam pulse water infusion is simulated through secondary development of ABAQUS software. During this process the mathematical model of the strain accumulation model due to the periodic changes of pulse water pressure is embedded in SOIL module of ABAQUS software discussed in this paper, in order to obtain the dynamic damage evolution rule of coal seam around the pulse water infusion hole. It provides a new quantitative method of determining coal seam pulse water infusion parameters and location. The law of different parameters of pulse water infusion on the dynamic damage evolution of coal around the infusion hole is gotten. Numerical simulation results show that, during the process of coal seam high pressure pulse water infusion, the stress field and flow field are mutual influence and mutual restriction. The coupling of the stress and flow field have impact on the physical and mechanical properties of coal in front of the working face, these factors promote each other and prevent coal and gas outburst effectively. The coal damage quantity increases significantly with the water infusion time prolonging under constant water infusion pressure and frequency. The coal damage quantity increases significantly with the water infusion pressure increasing under constant water infusion time and frequency. The coal damage quantity increases significantly with the water infusion frequency increasing under constant water infusion pressure and time. So the pulse water infusion time needs to ensure a better effect of preventing coal and gas outburst is gotten. Meanwhile the pulse water infusion pressure needs to improve under the existing technical conditions. The frequency of pulse water infusion needs to improve under the existing technical conditions. This research results contribute to obtain accurate dynamic distribution law of damage fields around water infusion holes. It provides theoretical basis for optimizing pulse water infusion in technological parameters design and raising water infusion effect.