CN115875040A - A method for judging the boundary of the void area in the excavation face - Google Patents

Abstract

The invention discloses a method for judging a boundary of a goaf encountered on a tunneling working face, which comprises the following steps: detecting the distribution form of a goaf with the advance of 30m by adopting a transient electromagnetic method; selecting a drilling path according to the probing result; arranging drill holes, drilling a goaf, stopping drilling when the goaf is found, and returning; and (3) extending the high-precision scanning probe into the goaf through a drilling hole to perform scanning identification, and obtaining the boundary of the goaf. The invention adopts a geophysical prospecting and drilling method, integrates the advantages of the geophysical prospecting and drilling method, provides guidance for the drilling path of drilling, and avoids the occurrence of drilling sticking and drilling dropping accidents when drilling to a rock crushing area; meanwhile, the target drilling area is optimized through the cooperation of geophysical prospecting and drilling, and the exploration efficiency is improved.

Description

A method for judging the boundary of the void area in the excavation face

technical field

The invention belongs to the technical field of recovery of residual coal resources in goafs, and in particular relates to a method for judging boundaries of goafs in excavation working faces.

Background technique

Mined-out area is the "hole" below the surface formed by human excavation during mining activities. The existence of gobs makes the construction and operation of various projects face great safety problems. In the process of mine integration, the partially integrated small mines have insufficient resource mining due to backward mining technology, and also formed many goafs that are difficult to explore. To recover the remaining resources in the goaf, it is necessary to excavate the roadway and conduct exploration during the excavation process .

The existing goaf detection methods mainly include three types. The first one is to detect the goaf through large-scale geological detection equipment. However, since the location of the gob is unpredictable and the weight of the large equipment is heavy, once the large equipment is placed Arranged within the range of the goaf, it is very easy to cause geological collapse, and there is a risk of staff and equipment falling into the goaf. The second is to establish a ground pressure monitoring network for long-term and effective monitoring of ground pressure. Usually, the period of establishing a ground pressure monitoring network is too long, and because the goaf is large or small, the ground pressure detection network cannot accurately monitor Smaller gobs, less accurate. The third is a geophysical method that indirectly measures gobs by measuring the distribution of formation resistivity (high density electrical method) or dielectric constant (ground radar). The resistivity method is a volume effect, which has the problem of low spatial resolution, and the detection depth of the radar is shallow, which makes the accuracy of the detection results low.

Contents of the invention

Based on the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a method for judging the boundary of the void area in the excavation working face, which is simple, efficient and accurate, and can be accurately judged in various complex roadway excavation and working face excavation processes. The boundary of the encounter zone.

In order to solve the above-mentioned technical problems, the present invention is achieved through the following technical solutions: the present invention provides a method for judging the boundary of the void area in the excavation face, comprising the following steps:

S1. Use the transient electromagnetic method to detect the distribution pattern of the 30m gob ahead;

S2. Select the drilling path according to the exploration results; arrange the drilling, drill to the goaf, stop drilling when the goaf is found, and return;

S3. Extend the high-precision scanning probe into the goaf through the borehole to scan and identify the goaf to obtain the goaf boundary.

Optionally, the step S1 includes: adopting a center loop device for the transient electromagnetic method survey, and the detection measuring points are arranged head-on on the working face.

Further, the advanced detection of transient electromagnetic method is used to arrange three survey lines at 30° on the roof in front of the roadway, along the direction of bedding roadway excavation, and at 30° below the floor in front of the roadway.

Furthermore, 11 physical measuring points are arranged on the roof, bedding roadway and floor respectively, and the angle is extended from 50° to 50° from the left, and a physical measuring point is placed at an angle interval of 10°. A total of 33 data collection points have been completed.

Furthermore, the detected range is a fan-shaped area, and each physical measuring point has data in three time periods: early, middle, and late.

Optionally, in the step S2, it is determined whether the goaf has been reached according to the drilling speed, water output and gas concentration, so as to delineate the boundary of the goaf.

Further, the boundary of the goaf is determined within the geophysical prospecting range by drilling and exploration. During the drilling process, when encountering the broken area of the surrounding rock in front, continue to drill forward until the goaf is found, stop drilling, and Withdraw the drill.

Further, the high-precision scanning probe is connected to the rod body through a rotating buckle; a protective cover is provided on the outside of the high-precision scanning probe, and the first, second, third and fourth lenses are provided inside the protective cover.

Further, a 3D model is constructed by 3D laser scanning, the volume of residual coal in the goaf is estimated, and the scope and boundary of the goaf are determined.

From the above, a kind of advanced drilling+geophysical prospecting comprehensive analysis provided by the present invention determines the goaf boundary judgment method, adopts the mine transient electromagnetic method to explore the distribution form of the 30m goaf in advance; 1. Arrange measuring lines at 30° below the tunneling direction of the bedding roadway and the floor of the roadway, and then arrange 11 physical measuring points on the roof, bedding roadway and floor respectively, from 50° from left to 50° right, and arrange a physical measuring point every 10° , forming a fan-shaped area. Extract the geoelectric information obtained by the mine transient electromagnetic method and conduct qualitative analysis on the geological data of the excavation face, so as to obtain the geological structure of the excavation face ahead, deduce the general shape of the goaf, and provide the optimal drilling path ; In addition, the complete situation of the excavated coal and rock mass can also be obtained. Obtain the geological structure according to the transient electromagnetic method, choose the appropriate drilling angle, avoid the rock in the broken area, and avoid the occurrence of drill sticking and drill drop accidents in the rock broken area; according to the drilling speed, water output and gas The concentration determines whether the boundary of the goaf is reached; when the goaf is found, the drilling is stopped and the drill bit is withdrawn. Put the high-precision scanning probe connected by the rotating buckle and the rod body into the borehole to scan the inside of the gob. Optimize the emitted laser, effectively eliminate the aberration effect at the edge position, and improve the accuracy of the high-precision scanning probe. The distance and relative position are calculated by using the time of the pulsed laser to travel back and forth over the measured distance and the emission angle of the pulsed laser, and a three-dimensional graph of the goaf is established through a special data collection and imaging system to estimate the volume of residual coal in the goaf and determine Goaf area and boundaries.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , below in conjunction with the preferred embodiment, and with the accompanying drawings, the detailed description is as follows.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings of the embodiments will be briefly introduced below.

Fig. 1 is the schematic flow chart of the method for judging the boundary of the void area in the driving face of the present invention;

Fig. 2 is a schematic diagram of the boundary judgment method of the working face encountering a void area.

Among them, 1-excavation roadway, 2-geophysical prospecting equipment, 3-optimal drilling path, 4-empty area ahead, 5-high-precision scanning probe, 6-geophysical prospecting range, 7-surrounding rock crushing area ahead.

Detailed ways

The specific implementation of the present invention will be described in detail below in conjunction with the accompanying drawings. As a part of this specification, the principles of the present invention will be described through examples. Other aspects, features and advantages of the present invention will become clear through the detailed description. In the referenced drawings, the same reference numerals are used for the same or similar components in different drawings.

As shown in Figure 1, the method for judging the boundary of the ditch face of the present invention includes the following steps:

Step 1: Test the distribution of gobs within 30m ahead of the tunneling process using the transient electromagnetic method of the mine, and check the layout of the coil and the front of the working face, at 30° on the roof in front of the tunnel, the direction of tunneling along the bedding, and the direction of the tunnel. The measuring line is arranged at 30° below the floor, and then 11 physical measuring points are arranged on the roof, bedding roadway and floor respectively, from 50° left to 50° right, and a physical measuring point is arranged every 10° to form a fan-shaped area.

The present invention uses mine transient electromagnetic method, time-domain artificial electromagnetic detection method based on electromagnetic induction, its principle is to use ungrounded TX (magnetic source) to transmit a pulsed magnetic field to the working face, also called primary magnetic field; , the induced eddy current excited in the ore body with good conductivity is a time-decayed eddy current field, which can stimulate a time-varying induced electromagnetic field, also known as the secondary field. The decay process is generally divided into early, middle and late stages, and a total of 33 data points were collected. Various geoelectric information can be reflected according to the time-changing induced electromagnetic field, such as the shape, size, position, and conductivity of ore bodies with good conductivity; use the receiving coil RX to observe the response field in the pulse magnetic field interval, and the The corresponding information is extracted and qualitatively analyzed with the geological data of the excavation face, so as to obtain the geological structure of the excavation face ahead, deduce the general shape of the goaf, and provide the optimal drilling path. The geological conditions in the mine are complex, and it is necessary to collect and investigate all the known geological data in the area of the excavation working face, so as to better grasp the geological characteristics of the goaf, so as to judge the scope of the broken surrounding rock area in front and the general shape of the goaf .

For example, water, as a conductor, often threatens the safe production of coal mines, so the transient electromagnetic method is often used in hydrogeological exploration of coal mines, and can also detect whether there is water in the goaf to avoid accidents during excavation.

The invention qualitatively analyzes the extracted information and the geological data of the excavation working face, so as to obtain the geological structure of the excavation working face in front, deduce the general shape of the goaf, and provide the optimal drilling path.

Step 2: Obtain the geological structure of the working face according to the transient electromagnetic method, judge the integrity of the coal and rock mass ahead, and select the appropriate drilling angle based on the actual situation of the mine to avoid rocks in the broken area and avoid drilling to the broken rock area. Drilling and falling drill accidents.

Step 3, based on step 2, arrange the drill holes in the optimal drill hole area, which can be drilled by geological drilling rigs; or drilled by manual drills, according to the drilling speed, water output and gas concentration Determine whether to reach the boundary of the goaf; when the goaf is found, stop drilling and withdraw the drill bit.

Step 4, put a high-precision scanning probe into the drilled hole in step 3 to scan the inside of the goaf. The high-precision scanning probe is connected to the rod body through a rotating buckle, which is convenient for installation and disassembly, and improves work efficiency; There is a protective cover on the outside of the precision scanning probe, and the first, second, third, and fourth lenses are installed on the inside of the protective cover. Through the cooperation of each lens, the emitted laser is optimized to effectively eliminate the aberration at the edge and improve high-precision scanning. The accuracy of the probe; the distance and relative position are calculated by using the time of the pulsed laser to travel back and forth on the measured distance and the emission angle of the pulsed laser, and a three-dimensional figure of the goaf is established through a special data collection and imaging system to estimate the remaining time of the goaf Coal volume, determine the range and boundary of the goaf.

When arranging the boreholes, the drilling exploration method of the geological drilling rig or the manual drilling exploration method can be selected.

The detection coil is arranged directly in front of the working face, and the measuring line is arranged at 30° on the top plate in front of the roadway, the excavation direction of the bedding roadway, and 30° below the roadway bottom plate, and then 11 physical measuring points are arranged on the roof, bedding roadway and bottom plate respectively. From 50° to 50° to the right, a physical measuring point is arranged every 10° to form a fan-shaped area.

As shown in Figure 2, geophysical prospecting equipment 2 is arranged 30m in front of the excavation roadway 1, and the scope of exploration using the mine transient electromagnetic method is the geophysical prospecting scope 6. According to the qualitative analysis of the information extracted from the exploration and the geological data of the excavation working face, Obtain the geological structure of the front excavation working face, deduce the general shape of the goaf, and provide the optimal drilling path 3 and the front surrounding rock crushing area 7, through the drilling exploration method of geological drilling rig or manual drilling exploration Arrange the borehole, put the high-precision scanning probe 5 into the borehole, use the time of the pulse laser to travel back and forth over the measured distance and the emission angle of the pulse laser to convert the distance and relative position, and use a special data collection and imaging system Establish a three-dimensional graph of the goaf, estimate the residual coal volume and water accumulation in the goaf, and then determine the scope and boundary of the goaf 4 ahead.

The above description is only a preferred embodiment of the present invention, and of course the scope of rights of the present invention cannot be limited by this. It should be pointed out that for those of ordinary skill in the art, they can also Several improvements and changes are made, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims (9)

1. A method for judging the boundary of a goaf of a tunneling working face is characterized by comprising the following steps:

s1, exploring the distribution form of a goaf 30m ahead by adopting a transient electromagnetic method;

s2, selecting a drilling path according to the probing result; arranging drill holes, drilling a goaf, stopping drilling when the goaf is found, and returning;

and S3, extending the high-precision scanning probe into the goaf through the drill hole to perform scanning identification, and obtaining the boundary of the goaf.

2. The method for determining the goaf boundary on the tunneling working face according to claim 1, wherein the step S1 comprises: the transient electromagnetic method exploration adopts a central loop device, and detection measuring points are arranged on the head of a working face.

3. The method for determining the boundary of the gob on the tunneling working face according to claim 2, wherein three measuring lines of 30 degrees above the top plate in front of the roadway, 30 degrees below the bottom plate in front of the roadway and the tunneling direction of the roadway on the same level are probed in advance by a transient electromagnetic method.

4. The method for judging the boundary of the gob in the tunneling working face according to claim 3, wherein 11 physical measuring points are respectively arranged on the top plate, the bedding roadway and the bottom plate, the angle is expanded from left 50 degrees to right 50 degrees, one physical measuring point is placed at an angle interval of 10 degrees, and 33 data acquisition points are completed in total.

5. The method for determining the boundary of the goaf on the tunneling working face according to claim 4, wherein the detected range is a sector area, and each physical measuring point has data of three time periods, namely an early period, a middle period and a late period.

6. The method for determining the boundary of the goaf on the tunneling working face according to claim 1, wherein in step S2, whether the goaf is reached is determined according to the drilling speed, the water yield and the gas concentration, so as to define the boundary of the goaf.

7. The method for judging the boundary of the goaf encountered by the heading face according to claim 6, wherein the boundary of the goaf is determined within a geophysical prospecting range through a drilling exploration mode, drilling is continued forwards when a surrounding rock crushing region ahead is encountered in the drilling process, drilling is stopped until the goaf is found, and a drill bit is withdrawn.

8. The method for judging the boundary of the goaf on the tunneling working face according to claim 1, wherein the high-precision scanning probe is connected with the rod body through a rotary buckle; the outside of high accuracy scanning probe is equipped with the one deck safety cover, and the safety cover inboard is equipped with first, two, three, four lens simultaneously.

9. The method for judging the boundary of the goaf on the tunneling working face according to claim 8, wherein a three-dimensional model is constructed through three-dimensional laser scanning, the volume of residual coal in the goaf is estimated, and the range and the boundary of the goaf are determined.

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