Analysis on water conductivity of fault based on pumping test and dewatering test

Abstract

In order to avoid the water disaster of fault and sandstone below the coal seam, it is necessary to master the conductivity of fault accurately. Through the dewatering test with large drawdown and water flow of Baotashan sandstone aquifer in the bottom of Yan’an Formation, the good conductivity of DF20 fault in vertical was found out, and the DF20 fault is an important hydraulic connection channel of each aquifer. It is clear that DF20 and F2 fault have hydraulic connection in horizontal direction, and Triassic aquifer has the hydraulic connetion with Baotashan sandstone aquifer by DF20 and F2 faults. It is proposed that the intersection of DF20 and FD5 faults has the strongest conductivity and is the main location of water exchange of each aquifer. The conductivity of DF20 fault is not uniform in the horizontal direction. The conductivity of DF20 fault located in the middle of the coal field is weak, while the conductivity of DF20 fault in the south of the coal field is strong. The results show that the hydrogeological parameters of the fault not only can be obtained through the pumping test and dewatering test, but also the hydrogeological conductivity and spatial characteristics of the fault can be found out.

Keywords

• jurassic coalfield
• fault
• water conductivity
• pumping test
• dewatering test
• groundwater flow field