Fracturing relief method for stress concentration of remaining ore pillars in overlying goaf

A fracturing relief method for stress concentration of remaining ore pillars in an overlying goaf, comprising the following steps:

• step 1:
• separately constructing three rows of fracturing drill holes in a roadway to a set depth at an interval in a direction oblique to a coal pillar in an upper goaf by using a drilling machine, wherein a position of a final hole of a first row of the fracturing drill holes is 1 m above a middle of a main roof above the coal pillar, a position of a final hole of a second row of the fracturing drill holes is 1 m above a middle of the coal pillar, and a position of a final hole of a third row of the fracturing drill holes is at a section of ¾ of the coal pillar;
• step 2:
• mounting and commissioning a hydraulic fracturing high-pressure pump and a hydraulic fracturing pulse pump;
• step 3:
• sending a packer to a to-be-fractured area of a to-be-fractured drill hole, sequentially connecting a high-pressure seal mounting rod, a transfer joint and a high-pressure pipeline, and separately connecting the high-pressure pipeline to the hydraulic fracturing pulse pump and the hydraulic fracturing high-pressure pump through a three-way valve;
• step 4:
• performing high-pressure hydraulic fracturing on a main roof area in the first row of the fracturing drill holes, and then performing pulse hydraulic fracturing on a coal pillar area in the first row of the fracturing drill holes;
• step 5:
• performing pulse hydraulic fracturing on the second row of the fracturing drill holes;
• and
• step 6:
• performing pulse hydraulic fracturing on the coal pillar area in the third row of the fracturing drill holes, and then performing pulse hydraulic fracturing again on a floor area in the third row of the fracturing drill holes.