开采设计对薄基软岩工作面防治水的影响研究

Study on influence of engineering design and mining on water prevention and control of soft rock with thin foundation

防治水工作是综合性系统工程,在传统的煤矿生产过程中主要通过防、堵、疏、截、排、监等方式进行治理,治理效果良好,但在治理过程中从顶板岩性组合、工作面推采速度及开采工艺等因素对防治水影响方面的考虑较少,在一定程度上减弱治理工程的效果。以伊犁矿区某矿21103工作面与21105工作面为背景,结合其顶板岩性组合、地表沉降及实际涌水情况,研究了工作面设计、推采速度等因素对防治水工作的影响,通过现场实测及理论分析,重点研究薄基软岩顶板、工作面设计及推采速度对顶板导水裂隙高度发育情况的影响。根据其顶板为中砂岩、细砂岩、泥岩与砂岩互层的岩性组合特征,对弯曲下沉带与导水裂隙带高度实测,将实测结果与理论计算进行对比,结合地面受采动影响沉降情况,分析薄基软岩顶板的冒落规律,得到在采动影响下顶板软岩层会以周期整体冒落的形式出现,同时由于岩性强度小,能及时压实产生的裂隙,快速堵塞导水通道,可以减小导水裂隙带发育高度,从而消除水害威胁;再结合工作面设计与支护方式以及推采速度,通过分析实际推采过程中涌水情况及出水位置,分析研究工作面设计与推采速度对裂隙发育高度的影响,得到不规则的工作面设计、超强的支护以及无规律的采动都能增加裂隙的发育高度,从而增加导通含水层的可能性,增大水害威胁。

Water prevention and control work is a comprehensive system engineering.In the traditional coal mine production process,the main way is prevention,blocking,drainage,interception,drainage and supervision,and good results have been achieved.However,in the treatment process,the influence of roof lithology combination,pushing mining speed and working face design on water disaster is less considered,which weakens the effect of treatment project to a certain extent.Based on the No.21103 working face and No.21105 working face of a mine in Yili Mining Area as the background,combined with the roof lithology combination,surface subsidence and actual water gushing situation,this paper studies the influence of working face design and pushing mining speed on water prevention and control work.Through the combination of field measurement and theoretical analysis,the influence of thin soft rock roof,working face design and pushing speed on height development of roof is studied.According to the lithologic combination characteristics of the roof of medium sandstone,fine sandstone,mudstone and sandstone interbedding,through the measured results of the height of bending subsidence zone and water conducting fracture zone,and compared with the theoretical calculation,combined with the ground subsidence affected by mining,the caving law of soft rock roof on thin.Foundation is analyzed,and it is concluded that the roof soft rock strata will fall in the form of periodic whole under the influence of mining.At the same time,due to the low strength of lithology,the cracks generated can be compacted in time,the water diversion channel can be quickly blocked,and the development height of water flowing fracture zone is smaller,thus reducing the threat of water disaster.Combined with the design of working face and support mode and push mining speed,through the analysis of actual water inflow and water outlet position in the process of pushing mining,the influence of working face design and pushing mining speed on fracture development height is analyzed and studied.It is concluded that irregular working face design,super strong support and irregular mining can increase the development height of fractures,thus increasing the possibility of conducting aquifer and the threat of water damage.