Discussion on water prevention and control technology of roadway tunneling in water-rich coal seam in northern Yuheng Mining Area

Abstract

In order to solve the problem of No. 2 coal seam water hazards during the roadway tunneling process of the water-rich coal seam in northern Yuheng Mining Area, taking Balasu Coal Mine as an example, and combining the previous mining experience, firstly, the advanced drilling engineering （short drill + long drill） and the hydrochemical analysis in the rock roadway are carried out, and then the drainage water exploration ideas for the tunneling of the special coal seam water hazards in this area is proposed. The results show that the water drainage effect of the drilling project of No.2 coal seam in the early stage is remarkable, and the water volume and water pressure attenuation of each drill hole are obvious, indicating that the water recharge condition of No.2 coal seam is poor, and the whole coal seam belongs to the state of static water occurrence. Through the full analysis test of coal seam water, it is found that the water quality type of No.2 coal seam is basically SO4-Na·（Ｃａ） type water, with the pH value between 7.63-8.04 and a total salinity of 5 820.88 mg/L to 6 202.99 mg/L. It is believed that the water runoff and discharge conditions are limited and the water is in a closed state for a long time, which is conducive to the development of water drainage. Therefore, the ideas of drainage water exploration suitable for the roadway tunneling of No.2 coal seam in this area is proposed, including drilling technical schemes such as “double funnel mode”, “advance screen mode”, “lower coal drainagemode” and “bilateral feather mode”.

Keywords

• balasu coal field
• water-rich coal seam
• roadway tunneling
• drilling engineering
• water prevention and control