煤层火烧区边界“两探”措施的探索及应用

Exploration and application of “two exploration” measures at boundary of coal seam burning area

邻近火烧区边界的A3煤层顶底板及围岩经火烧、烘烤,改变了原岩的性质,裂隙杂乱无序,孔洞发育,具备良好的导水通道和储水空间,巨厚的烧变岩层使区内各含水层相互联通,对矿井开采构成威胁。基于控制A3煤层火烧区边界,修订火烧区边界线,防治火烧区水害,以及现场"两探"措施的实践,提出在邻近A3煤层火烧区边界施工巷道时,严格落实超前物探,钻探验证"两探"措施,保留超前距,执行允掘通知单制度;施工A3煤层火烧区边界探查孔,根据结果动态修正火烧区边界线;在顶板施工1个A5煤层火烧区底界探查孔,控制上覆A5煤层火烧区积水情况。实践结果表明:通过落实"两探"措施,物探、钻探方法相互验证,可以有效确定施工前方异常区有无积水,对施工有无威胁;逐步查明A3煤层火烧区富水性,精准控制火烧区边界,有效疏放火烧区积水,圈定A3煤层的安全可采区域;摸清位于A3探巷以西的火烧区积水补给循环条件不畅,未受到库车河水补给影响,为静态储量,可以疏放干净,待积水疏放完毕后,消除火烧区水害威胁。

The roof,floor of A3 coal seam and surrounding rock near the boundary of the burning area have been burnt and baked,which has changed the nature of the original rock.The fractures are disordered with well-developed pores.It has good water conducting channels and water storage spaces.A huge burnt rock layer connects all aquifers in the area and poses a threat to the mining.Based on the practice of controlling the boundary of the burning area of A3 coal seam,revising the boundary line of the burning area,preventing the water damage in the burning area.Taking the on-site"two exploration"measures,it is proposed to strictly implement the"two exploration"measures when constructing roadways adjacent to the boundary of the burning zone of the A3 coal seam,advance geophysical prospecting and drilling verification,retain the advance distance,and implement the excavation notice system;construct the A3 coal seam burning zone boundary exploration hole,and dynamically modify it according to the results of boundary line of the burning area;construct an exploration hole at the bottom boundary of the A5 coal seam burning area on the roof to control the water accumulation in the burning area of the overlying A5 coal seam.The practical results show that:through the implementation of the"two exploration"measuresand mutual verification of geophysical prospecting and drilling methods,it is possible to effectively determine whether there is accumulated water in the abnormal area ahead of the construction and whether there is a threat to the construction;gradually identify the water abundance of the A3 coal seam burning area,accurately control the boundary of the burning area,effectively drain the water in the burning area,and delineate the safe and mineable area of the A3 coal seam.It is found out that the water replenishment cycle conditions in the burning area west of the A3 exploration entryare not smooth,and it is not affected by the water replenishment of the Kuqa River.It is a static reserve and can be drained clean.After the water is drained,the threat of water damage in the burning area is eliminated.