Study on mechanism of pressure relief by deep hole blasing and technique system to control floor heave on the roadway floor

The weak rock strength and high stress in the floor leads to significant floor heave in the E2305 working face of Gaohe coal mine.The mechanism to explain floor heave is calculated using the FLAC^3D software, and a technique system that is namely deep hole blasing and loosing, is proposed.An analog simulation is used to analyze patterns of mine pressure, stress distribution and displacement of roadway surrounding rock, and break behavior of the roadways.The floor heave patterns are compared under the conditions with or without the blasing treatment, the results show that the blasting technique system can alleviate floor heave effectively.The maximun floor heave is 55 mm, and the maximun floor heave rate is 21 mm/d, which are both in a normal range.The successfully application of blasting and loosing technique system could help other similar projects to control floor stability.