Roof rock stratum caving zone optical fiber monitoring method

Abstract

The roof rock stratum caving zone optical fiber monitoring method provided by the embodiment of the invention comprises the following steps: S1, dividing a roof rock stratum with a caving zone above a stope face to be mined into a monitoring rock stratum; s2, multiple monitoring holes penetrating through the caving zone are formed in the monitoring rock stratum, monitoring optical fibers are installed in the multiple monitoring holes, and the multiple monitoring optical fibers are all connected with a monitoring device; s3, slurry is injected into the monitoring holes so as to form filling bodies for filling the monitoring holes; and S4, judging the height of the caving zone by using the strain data detected by the monitoring optical fiber. Therefore, the roof rock stratum caving zone optical fiber monitoring method provided by the embodiment of the invention has the advantages of convenience in real-time monitoring, high durability and high safety.

Description

Technical Field

[0001] The invention relates to the technical field of mining, and in particular to an optical fiber monitoring method for a roof rock stratum collapse zone. Background Art

[0002] The size of the roof rock collapse zone affects the selection of working face equipment and mine pressure management. The larger the collapse zone, the stronger the mine pressure generated by the migration of overburden. Among the related technologies, the methods for judging the height of the collapse zone mainly include observation of drilling flushing fluid leakage, drilling peeping, electrical method, microseismic monitoring, etc. The monitoring accuracy is limited, the monitoring range is limited, and it is difficult to fully cover the roof collapse zone, resulting in local stress changes and small displacements that are not easy to be discovered in time. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides an optical fiber monitoring method for a roof rock collapse zone.

[0004] The optical fiber monitoring method for roof rock collapse zone of the embodiment of the present invention comprises the following steps:

[0005] S1. Classify the top rock layer with the collapse zone above the mining working face to be mined as the monitoring rock layer;

[0006] S2, opening a plurality of monitoring holes penetrating the collapse zone in the monitoring rock layer, installing monitoring optical fibers in the plurality of monitoring holes, and the plurality of monitoring optical fibers are all connected to a monitoring device;

[0007] S3, injecting slurry into the monitoring hole to form a filling body filling the monitoring hole;

[0008] S4. Determine the height of the collapse zone using the strain data detected by the monitoring optical fiber.

[0009] Therefore, the optical fiber monitoring method for the roof rock collapse zone according to the embodiment of the present invention has the advantages of easy real-time monitoring, strong durability and high safety.

[0010] In some embodiments, in step S2, a plurality of monitoring holes are opened upward in a tunnel on the side of the mining face to be mined.

[0011] In some embodiments, in step S2, each of the monitoring holes includes a first borehole and a second borehole, the first borehole is arranged to be inclined upward, and the second borehole extends in a horizontal direction.

[0012] In some embodiments, in step S2, the second borehole is located in the middle of the mining face in the width direction of the mining face, the second borehole extends along the mining direction of the mining face, and the first borehole is inclined in the horizontal direction along the direction adjacent to the second borehole.

[0013] In some embodiments, in step S2, a plurality of second boreholes spaced apart in the up-down direction are provided in the monitoring rock formation, and a distance between two adjacent second boreholes in the up-down direction is greater than or equal to 5 meters and less than or equal to 10 meters.

[0014] In some embodiments, in step S2, after the monitoring optical fiber is fixed to the outside of the filling tube, the filling tube is pushed into the monitoring hole;

[0015] In the step S3, the slurry is injected into the monitoring hole by using the filling pipe.

[0016] In some embodiments, the filling tube is formed by connecting multiple sections of plastic pipes, and the monitoring optical fiber is fixed to the outside of the filling tube using a cable tie.

[0017] In some embodiments, in step S3, a first filling body located on the outside of the filling tube is first injected into the orifice of the monitoring hole to form a slurry to block the orifice of the monitoring hole, and the first filling body is located on the outside of the filling tube, and then the slurry is injected into the monitoring hole through the filling tube.

[0018] In some embodiments, the length of the first filling body is greater than or equal to 5 meters.

[0019] In some embodiments, the openings of the multiple monitoring holes are adjacent to each other, the monitoring optical fibers in the multiple monitoring holes are connected in series at the openings of the multiple monitoring holes, and the monitoring optical fibers located outside the monitoring holes are cooled to determine the monitoring distance of the monitoring optical fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a top view of a monitoring hole according to an embodiment of the present invention.

[0021] Figure 2 is a side view of a monitoring hole according to an embodiment of the present invention.

[0022] Figure 3 is a schematic diagram of a filling tube according to an embodiment of the present invention.

[0023] Figure numerals: 1. coal pillar, 2. goaf, 3. monitoring optical fiber, 4. filling pipe, 5. mining working face, 6. monitoring rock layer, 7. bottom plate, 9. screws. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0025] The following describes the optical fiber monitoring method for the roof rock collapse zone according to an embodiment of the present invention with reference to the accompanying drawings. Figures 1 to 3 As shown, the optical fiber monitoring method for roof rock collapse zone according to an embodiment of the present invention comprises the following steps:

[0026] S1. The roof rock layer with the collapse zone above the mining face 5 to be mined is divided into the monitoring rock layer 6. Specifically, the mining face 5 is located above the bottom plate 7, and the goaf 2 is formed after the mining face 5 is mined. A detailed geological survey is conducted on the inner side of the roof rock layer above the mining face 5 to be mined, so as to analyze the rock mass physical and mechanical parameters, roof rock layer structure, bedding joints and fissure distribution of the roof rock layer. The position of the collapse zone is analyzed by empirical formulas, theoretical analysis and actual measurement of mine pressure data to obtain the approximate monitoring layer, thereby dividing the monitoring rock layer 6 that wraps the collapse zone.

[0027] S2. A plurality of monitoring holes are opened in the monitoring rock layer 6 and penetrate the collapse zone. Monitoring optical fibers 3 are installed in the plurality of monitoring holes. The plurality of monitoring optical fibers 3 are all connected to the monitoring device (monitoring station). Specifically, the diameter, depth, inclination and azimuth of the monitoring hole are determined according to the on-site conditions to ensure that the monitoring optical fiber 3 is convenient for monitoring the collapse zone after being installed in the monitoring hole, so that the monitoring optical fiber 3 can monitor the strain in the collapse zone.

[0028] like Figure 1 As shown, in some embodiments, in step S2, a plurality of monitoring holes are opened upward in the tunnel on the side of the mining face 5 to be mined. Specifically, monitoring holes are opened upward in the tunnel that has been opened, and the monitoring holes are located above the mining face 5, and each monitoring hole is provided with a monitoring optical fiber 3. For example, a tunnel can be opened in the coal pillar 1 on the side of the mining face 5, and a plurality of monitoring holes can be opened in the tunnel using a directional drill, and at least part of the plurality of monitoring holes are arranged at intervals in the vertical direction.

[0029] In some embodiments, in step S2, each monitoring hole includes a first borehole and a second borehole, the first borehole is arranged obliquely upward, and the second borehole extends in the horizontal direction. Specifically, the second borehole is located in the middle position of the mining face 5 in the width direction of the mining face 5, and the second borehole extends along the mining direction of the mining face 5, that is, the second borehole is located in the middle position directly above the mining face 5. The first borehole is inclined in the horizontal direction along the direction adjacent to the second borehole. The monitoring rock layer 6 is multi-layered, and at least one second borehole is provided in each monitoring rock layer 6. Alternatively, a plurality of second boreholes are provided in the monitoring rock layer 6. For example, the length direction of the second borehole and the mining direction of the mining face 5 are both the direction of the ore body.

[0030] like Figure 2 As shown, in some embodiments, in step S2, a plurality of second boreholes (monitoring holes) spaced apart in the vertical direction are provided in the monitoring rock layer 6, and the distance between two second boreholes adjacent in the vertical direction is greater than or equal to 5 meters and less than or equal to 10 meters. A monitoring optical fiber 3 is provided in each second borehole, that is, the distance between the monitoring optical fibers 3 in two second boreholes adjacent in the vertical direction is greater than or equal to 5 meters and less than or equal to 10 meters. For example, the distance between two second boreholes adjacent in the vertical direction is 6 meters or 8 meters.

[0031] S3, injecting slurry into the monitoring hole to form a filling body filling the monitoring hole. The filling body can fill the monitoring hole and wrap the monitoring optical fiber 3, so that the monitoring optical fiber 3 can be connected to the monitoring rock layer 6 through the filling body, so that the monitoring optical fiber 3 can be used to monitor the strain of the monitoring rock layer 6.

[0032] In some embodiments, in step S2, after the monitoring optical fiber 3 is fixed on the outside of the filling tube 4, the filling tube 4 is pushed into the monitoring hole, thereby facilitating the installation of the monitoring optical fiber 3. In step S3, the slurry is injected into the monitoring hole using the filling tube 4, and the outlet of the filling tube 4 can inject the slurry into the bottom of the monitoring hole (the end away from the hole mouth).

[0033] In some embodiments, in step S3, the first filling body located at the orifice position of the monitoring hole is first injected into the slurry to form a first filling body that blocks the orifice of the monitoring hole, and the first filling body is located on the outside of the filling pipe 4. The length of the first filling body is greater than or equal to 5 meters, so that the first filling body can block the orifice of the monitoring hole, and then the slurry is injected into the monitoring hole through the filling pipe 4, so as to prevent the slurry from leaking from the opening toward the lower orifice, so as to fill the monitoring hole. For example, the slurry is first injected into the orifice position of the monitoring hole, and after standing for 48 hours until the cement slurry at the orifice position is completely solidified into the first filling body, the slurry is injected into the monitoring hole by segmented grouting. The length of the first filling body is 6 meters.

[0034] like Figure 3As shown, in some embodiments, the filling tube 4 is formed by connecting multiple sections of plastic pipes, and the monitoring optical fiber 3 is fixed to the outside of the filling tube 4 using a cable tie. Specifically, the plastic pipe (PVC pipe) is fixed using screws 9 and glue to form the filling tube 4, and the length of the filling tube 4 is adapted to the length of the monitoring hole.

[0035] In some embodiments, the openings of the multiple monitoring holes are adjacent to each other, and the monitoring optical fibers 3 in the multiple monitoring holes are connected in series at the openings of the multiple monitoring holes. Specifically, 5 m of monitoring optical fiber 3 is reserved at the opening of each monitoring hole so that the monitoring optical fibers 3 at different layers can be connected in series. The connected monitoring optical fibers 3 are thermally fused with the communication optical cable and protected with a junction box, and then led to the ground to establish a monitoring station.

[0036] In some embodiments, the monitoring optical fiber 3 located outside the monitoring hole is cooled to determine the monitoring distance of the monitoring optical fiber 3. Specifically, the monitoring optical fiber 3 outside the orifice of the monitoring hole is cooled by spraying a condensing agent, so as to determine the length of the monitoring optical fiber 3 from the orifice of the monitoring hole to the bottom of the monitoring hole, and thus determine the monitoring distance of the monitoring optical fiber 3 from the orifice of the monitoring hole to the bottom of the monitoring hole. For example, the monitoring optical fiber 3 with a length of about 100 cm at the orifice of the monitoring hole is cooled by spraying a condensing agent.

[0037] S4. Determine the height of the collapse zone using the strain data detected by the monitoring optical fiber 3. Specifically, draw the strain curve inside the monitoring hole according to the monitoring result of the monitoring optical fiber 3, and determine the height of the collapse zone according to the maximum peak point of the strain curve of the monitoring optical fiber 3.

[0038] According to the optical fiber monitoring method for roof rock stratum collapse zone of the embodiment of the present invention, the monitoring optical fiber 3 is arranged in the monitoring rock stratum 6 with the collapse zone, and the monitoring hole is filled with a filling body. Therefore, the optical fiber monitoring method for roof rock stratum collapse zone of the embodiment of the present invention can realize high-precision and high-resolution real-time monitoring, and can monitor the strain and displacement changes of the fracture and collapse of the monitoring rock stratum 6. The optical fiber sensor (monitoring optical fiber 3) has the advantages of anti-electromagnetic interference, corrosion resistance, high mechanical strength, etc., and can work stably for a long time in harsh environments such as high temperature, high humidity, and dust, reducing maintenance requirements and costs, and ensuring the reliability and durability of the monitoring system. Distributed optical fiber sensing technology enables the system to cover a large area of ​​the roof area, realize multi-point and continuous monitoring, and provide comprehensive spatial and temporal data support. In addition, the monitoring optical fiber 3 adopts non-electrical energy transmission, which is inherently safe and particularly suitable for flammable and explosive mine environments, which can reduce the risk of electrical fires or explosions and ensure the safety of operators; the system can be managed through a remote monitoring platform to reduce the frequency of personnel entering dangerous areas.

[0039] Therefore, the optical fiber monitoring method for the roof rock collapse zone according to the embodiment of the present invention has the advantages of easy real-time monitoring, strong durability and high safety.

[0040] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0042] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0044] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0045] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for optical fiber monitoring of roof rock collapse zone, characterized in that: The following steps are involved: S1. Classify the top rock layer with the collapse zone above the mining working face to be mined as the monitoring rock layer; S2, opening a plurality of monitoring holes penetrating the collapse zone in the monitoring rock layer, installing monitoring optical fibers in the plurality of monitoring holes, and the plurality of monitoring optical fibers are all connected to a monitoring device; S3, injecting slurry into the monitoring hole to form a filling body filling the monitoring hole; S4. Determine the height of the collapse zone using the strain data detected by the monitoring optical fiber.

2. The optical fiber monitoring method for roof rock collapse zone according to claim 1 is characterized in that: In step S2, a plurality of monitoring holes are opened upward in a tunnel on the side of the mining face to be mined.

3. The optical fiber monitoring method for roof rock collapse zone according to claim 1 is characterized in that: In step S2, each of the monitoring holes includes a first borehole and a second borehole, the first borehole is arranged to be inclined upward, and the second borehole extends in a horizontal direction.

4. The optical fiber monitoring method for roof rock collapse zone according to claim 3 is characterized in that: In step S2, the second borehole is located in the middle of the mining face in the width direction of the mining face, the second borehole extends along the mining direction of the mining face, and the first borehole is inclined in the horizontal direction along the direction adjacent to the second borehole.

5. The optical fiber monitoring method for roof rock collapse zone according to claim 3 is characterized in that: In the step S2, a plurality of second boreholes spaced apart in the vertical direction are provided in the monitoring rock formation, and a distance between two adjacent second boreholes in the vertical direction is greater than or equal to 5 meters and less than or equal to 10 meters.

6. The optical fiber monitoring method for roof rock collapse zone according to claim 1 is characterized in that: In the step S2, after the monitoring optical fiber is fixed to the outside of the filling tube, the filling tube is pushed into the monitoring hole; In the step S3, the slurry is injected into the monitoring hole by using the filling pipe.

7. The optical fiber monitoring method for roof rock collapse zone according to claim 6 is characterized in that: The filling tube is formed by connecting multiple sections of plastic pipes, and the monitoring optical fiber is fixed to the outside of the filling tube by using a cable tie.

8. The optical fiber monitoring method for roof rock collapse zone according to claim 6 is characterized in that: In step S3, slurry is first injected into the orifice of the monitoring hole to form a first filling body that blocks the orifice of the monitoring hole. The first filling body is located outside the filling tube, and then slurry is injected into the monitoring hole through the filling tube.

9. The optical fiber monitoring method for roof rock collapse zone according to claim 8, characterized in that: The length of the first filling body is greater than or equal to 5 meters.

10. The optical fiber monitoring method for roof rock collapse zone according to claim 2, characterized in that: The openings of the plurality of monitoring holes are adjacent to each other, and the monitoring optical fibers in the plurality of monitoring holes are connected in series at the openings of the plurality of monitoring holes; The monitoring optical fiber located outside the monitoring hole is cooled to determine the monitoring distance of the monitoring optical fiber.

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