Technique of top coal caving with vibration

How to understand the top coal caving process and increase the top coal recovery ratio is one of the urgent problems to be resolved for the longwall top coal caving technology. The paper mainly studies a new theory and technique of top coal caving with vibration. The vibration device is mounted on the shield beam of the top coal caving support. The laboratory experiment and the numerical simulation were adopted in the study. The Distinct Element Method (DEM) numerical software (PFC2D) is used for the numerical simulation. Finally, the technique is applied to the 5209 top coal caving working face. Based on the experiment, the numerical simulation and the practice, the vibration can easily destroy the arch structure which is formed during the top coal caving process. The parameters about when the arch structure would be formed during the top coal caving process are obtained. The movement of the top coal caving process under the vibration condition makes a more stable layer uniform caving performance. The aim of the top coal caving with vibration technique, to increase the top coal recovery ratio and to lower the waste content rate, has been achieved.