New borehole sealing technology of gas pressure measuring borehole based on PD sealing material

In order to solve a poor borehole sealing quality of the gas pressure measuring borehole in Dashe Mine, the paper provided a new borehole sealing tech nology of the gas pressure measuring borehole based on PD sealing material. The PD sealing material was added to the conventional two sealing and one grouting ce ment grout borehole sealing technique. Meanwhile, a pressurized grouting process was added. The paper stated the borehole sealing principle and technique process of the new borehole sealing technology. A comparison experiment on the borehole sealing effect of the two type pressure measuring boreholes was conducted in the mine site. The results showed that in comparison with the conventional two sealing and one grouting cement grout sealing technology, in the same borehole with the same ge ological unit construction parameter, the seam gas pressure value measured with the new borehole sealing technology was 1.38 MPa and was bigger than measured m ax value 0.90 MPa with the conventional borehole sealing technology. Based on the PD sealing material, the sealing effect of the new borehole sealing technology for th e gas pressure measuring borehole was better and could obviously improve the sealing of the borehole. After 30 days, there was no pressure drop occurred on the gas pressure, the working time at the borehole sealing section was expanded, the gas pressure value measured was improved by 0.48 MPa and the accuracy of the pressur e measured was more higher.