ABSTRACT
KEYWORDS: Y-type ventilation, the second gob-side entry retaining, surrounding rock control technique
1. INTRODUCTION
Most coal mines are high gas mine in our country, for the sake of safety mining, many scholars at home and abroad did a lot of experiments on gas control of high gas coal face, after years of efforts and quests, a series of research results have been gained, and the system of mine safety technology is initially established, but traditional U-type ventilation is easy to form eddy in the upper-corner of return airway, and difficult to better dilute gushing gas from the goaf, thus causes gas accumulation in the upper-corner, as shown in the Figure 1(a), additionally coal seam of some mines is of soft low-permeability, currently the problem of gas overflow is not yet foundationally solved in the upper-corner, and it is recently one of the prime reasons causing gas accidents in the coal mines of our country, with the increase of mining depth and mining intensity, the frequency of gas disaster increases on the daily basis.
