CN-116498383-B - Impact dangerous area identification method based on in-hole impact and drilling stress distribution

Abstract

The invention discloses an impact dangerous area identification method based on in-hole impact and drilling stress distribution, and belongs to the technical field of coal mine safety exploitation engineering. The method comprises the steps of generating a stress distribution cloud chart of a region to be evaluated according to drilling stress obtained through inversion in a large-diameter drilling construction process, discretizing the region to be evaluated, carrying out stress attribute assignment on discrete block segments, obtaining a discrete block segment set containing intra-hole impact, clustering the discrete block segments of the region to be evaluated, calculating the intra-hole impact coverage rate of each subclass, calculating the number of clustered effective block segments meeting the set intra-hole impact coverage rate, and selecting the clustered effective block segment set with the least number of block segments as a final predicted impact block segment. And marking the block segments contained in the predicted intra-hole impact block segment set on the stress distribution cloud picture of the region to be evaluated according to the clustering analysis result. The method has simple steps and is convenient to quantify, and guidance can be provided for the development of later impact prevention and control work.

Inventors

• LI XUWEI
• WANG XIANGYU
• HUANG RUI
• LUO YU
• CAO ANYE
• SHENG SHIJIE
• DOU LINMING
• ZHANG XIUFENG
• MA XIANG
• HE HU
• BAI JIANBIAO

Assignees

• 中国矿业大学

Dates

Publication Date

20260505

Application Date

20230428

Claims (3)

1. 1. A method for identifying impact dangerous areas based on in-hole impact and drilling stress distribution is characterized in that an area to be evaluated is discretized into discrete stress block sections by utilizing drilling stress distribution state information and in-hole impact position information obtained in a drilling pressure relief process, and the stress similarity of each discrete stress block section and the stress block section with the in-hole impact is evaluated by utilizing three stress attributes of each discrete stress block section, namely stress magnitude, stress gradient along the drilling axial direction and stress gradient perpendicular to the drilling axial direction by adopting a clustering method, so that the stress block section with the potential for the in-hole impact is determined, wherein the method comprises the following specific steps: step 1, constructing a large number of large-diameter pressure relief holes in a region to be evaluated, and simultaneously acquiring stress distribution data of different depths of all large-diameter drilling holes, wherein the stress distribution data comprise stress magnitude and distribution data of impact in the holes; step 2, generating a stress distribution cloud picture of a region to be evaluated according to stress distribution data of a single large-diameter drilling hole obtained by inversion in the large-diameter drilling hole construction process, and obtaining the stress distribution of the region between the large-diameter drilling holes in an interpolation mode; step 3, discretizing a stress distribution cloud image of the region to be evaluated, dividing the stress distribution cloud image of the region to be evaluated into a plurality of block segments, performing stress attribute assignment on all the discrete block segments, and obtaining a discrete block segment set containing in-hole impact; Step 4, clustering the discrete block segments of the region to be evaluated according to the stress attribute values of the discrete block segments of the region to be evaluated, and then calculating the in-hole impact coverage rate of each subclass; Step 5, calculating the number of effective block segments of clusters meeting the set intra-hole impact coverage rate, and finally selecting an effective block segment set containing the clusters with the least number of block segments as a final predicted impact block segment; Step 6, marking the block segments contained in the predicted intra-hole impact block segment set on a stress distribution cloud picture of the region to be evaluated according to a clustering analysis result, and providing guidance for developing later impact prevention and control work; the discrete stress block section is characterized in that the region to be evaluated is divided into the size according to the requirement of the evaluation precision Rectangular block segment set of (a) Wherein the stress of the central position of each block section is as follows Stress gradient along the axial direction of the borehole is Stress gradient in vertical borehole axial direction Is a block section Stress attribute value of [ ] , , ) The subscript n is the total number of block segments divided by the region to be evaluated, the subscript X represents the drilling axial direction, the subscript Y represents the vertical drilling axial direction, the block segments containing the intra-hole impact are obtained according to the intra-hole impact distribution obtained during the large-diameter drilling construction period, and a set of intra-hole impact block segments is formed Wherein the number of the impacts in the holes is 。
2. 2. The method for identifying the impact hazard area based on the in-hole impact and drilling stress distribution according to claim 1, wherein the specific process of clustering all the discrete block segments according to the stress attribute values of the discrete block segments of the area to be evaluated is as follows: Firstly, the discrete block segments are grouped into class 2 ) Counting the number of the impact blocks in the holes contained in the 2 subclasses respectively ) The number of the impact block sections in the holes contained in each subclass ) Dividing by the total number of impact block segments in the hole ) The hole impact coverage rate of the corresponding subclass is respectively that of the 2 subclasses in the poly-2 subclasses And ; Similarly, class 3, class 4, class..m.. And class m were calculated separately ) The coverage rate of the impact in the holes of each class is% 、 、...、 ); Let the impact coverage in the hole to be satisfied be Counting and calculating the number of sub-class blocks meeting the hole impact coverage rate K when the class 2, the class 3, the class 4 and the class m are gathered, namely carrying out different combination summation on the sub-classes meeting the coverage rate K when the class m is gathered, finding out all combinations meeting the coverage rate more than or equal to K, then calculating the number of the blocks in each combination, selecting the combination with the least number of the blocks as the effective combination meeting the hole impact coverage rate K when the class m is gathered, and the number of the blocks contained in the combination is the effective number of the blocks meeting the hole impact coverage rate K when the class m is gathered.
3. 3. The method for identifying a critical area for impact based on hole impact and drilling stress distribution as claimed in claim 2, wherein the number of effective blocks satisfying the hole impact coverage rate K when the number of effective blocks satisfying the hole impact coverage rate K is equal to or greater than the number of effective blocks satisfying the hole impact coverage rate K when the effective blocks satisfying the effective impact coverage rate K is equal to the number of effective blocks satisfying the effective blocks 、 、...、 ) Stopping further clustering when the hole impact coverage rate is less than 50%, taking the number of effective blocks meeting the hole impact coverage rate K in the poly-m-1 class as the final predicted hole impact block number, and combining the effective blocks meeting the hole impact coverage rate K in the poly-m-1 class as the final predicted hole impact block set.

Description

Impact dangerous area identification method based on in-hole impact and drilling stress distribution Technical Field The invention relates to an impact dangerous area identification method based on in-hole impact and drilling stress distribution, and belongs to the technical field of coal mine safety exploitation engineering. Background Rock burst is a severe mine dynamic disaster that occurs primarily in connection with high stress concentrations in coal seams. The acquisition of the stress state in the coal seam is the basis for evaluating the risk of coal seam impact. The pressure relief of large-diameter drilling holes of a coal seam is one of main technical means for preventing rock burst, and for a coal seam roadway with rock burst, a large number of large-diameter drilling holes are required to be constructed along the roadway. When a large-diameter drilling hole is constructed, stress values of different depths of the drilling hole can be obtained through inversion by monitoring working states of the drilling machine and the drill rod, and further, evaluation of the dangerous state of the coal body of the roadway side near the drilling hole can be carried out by using drilling stress obtained through inversion, so that references are provided for rock burst prevention and control. During the construction of large diameter boreholes, the borehole section may reach a stress state where an impact occurs to cause an in-hole impact. The occurrence of the in-hole impact indicates that the stress state of the corresponding section of the drill hole is in a dangerous state, and under the condition of drilling unloading and loading disturbance, the impact damage can be induced in the coal seam, the impact kinetic energy is released, and the stability of the coal seam is threatened. For a borehole section and inter-borehole coal body that have similar stress conditions as the location of the in-hole impact, it may have a similar risk of an in-hole impact. At the same time, these areas are also potential impact hazards for future face recovery, and it is necessary to identify these areas. The prior art with the application number 201410422929.3 discloses a self-compensating controllable vibration source for shock wave CT detection of an impact dangerous area of a coal seam working face in a well and a vibration source generation method, and a row of holes are formed in the roadway side wall of the coal seam working face in the well. A vibroseis is installed in each borehole. The seismic source of the hydraulic in-hole tensioning mechanism is locked in the drilled hole through oiling expansion. The pneumatic type in-hole tensioning mechanism is characterized in that a hydraulic slotting cutter is needed to be used for slotting, a cylinder drives a claw plate to open, and the claw plate is tightly propped against the wall surface of the hydraulic slotting to lock the seismic source. The vibration wave energy and the frequency generated by the vibration source can be adjusted by adjusting the air source parameter and the electromagnetic parameter of the impact hammer. The method is complex in implementation, judgment is needed to be carried out by experience most of the time, and quantitative identification of specific areas is difficult. Disclosure of Invention Aiming at the defects of the prior art, the invention provides the impact danger area identification method based on the in-hole impact and drilling stress distribution, which has the advantages of simple steps, convenience for quantification and strong operability, and can identify the potential in-hole impact danger area of the coal roadway by utilizing the drilling stress distribution state information and the in-hole impact position information acquired in the drilling pressure relief process, so as to guide the coal roadway rock burst prevention and control work. The method is characterized in that the region to be evaluated is divided into discrete stress block sections by utilizing drilling stress distribution state information and drilling impact position information acquired in a drilling pressure relief process, and the stress similarity of each discrete stress block section and the stress block section with potential occurrence of the drilling impact is evaluated by utilizing three stress attributes of each discrete stress block section, namely stress magnitude, stress gradient along the drilling axial direction and stress gradient perpendicular to the drilling axial direction by adopting a clustering method. The method comprises the following specific steps: Step 1, constructing a large number of large-diameter pressure relief holes in a region to be evaluated, and simultaneously acquiring stress distribution data of different depths of all large-diameter drilling holes, wherein the stress distribution data comprise stress magnitude and distribution data of impact in the holes; step 2, generating a stress distribution cloud picture of a region