A method for controlling surrounding rock in high-extraction tunnels during mining

Abstract

The present invention discloses a method for segmented control of surrounding rock of high-extraction lanes facing mining excavation, which relates to the technical field of surrounding rock control of coal mine shafts and lanes. The specific steps are: by collecting relevant geological parameters of high-extraction lanes and facing mining working faces, using the horizontal and vertical distances between the high-extraction lanes and the facing mining working faces, and the geological parameters of the strata in which they are located and the overlying strata, a numerical model of the high-extraction lanes facing mining excavation conditions is established; based on the mining stress and rock strata movement conditions of the high-extraction lanes, the whole process of high-extraction lane excavation is divided into four stages; according to the surrounding rock stability conditions of the high-extraction lanes at different stages, different support methods are used in each stage to control the surrounding rock of the lanes. The present invention utilizes the characteristics of different degrees of difficulty in controlling the surrounding rock of high-extraction lanes facing mining excavation at different stages to perform segmented control of the surrounding rock of the lanes, thereby achieving reasonable segmentation of high-extraction lanes under the conditions of facing mining excavation, while improving the efficiency of controlling the surrounding rock of high-extraction lanes, and reducing the cost of lane excavation.

Description

Technical Field

[0001] The present invention relates to the technical field of surrounding rock control in underground coal mine tunnels, and more particularly to a segmented control method for surrounding rock in high-extraction tunnels facing mining. Background Art

[0002] As mining extends deeper, gas content and gas pressure are increasing, and the "bottleneck" problem of gas restricting production is becoming more and more prominent. The high-intensity mining of top coal has caused gas to exceed the limit in the corners of the working face and the return air lane, seriously affecting normal production and posing a huge threat to the safety of personnel and equipment. High-extraction lane gas extraction, as a major extraction method, can not only pre-extract gas precipitated from the coal body of the working face before mining, but also extract gas from the goaf of the working face. The arrangement of high-extraction lanes has been significantly effective in solving gas exceeding the limit in the corners of the working face and improving the working environment of the working face. However, in recent years, due to the increased intensity of mine mining and the tense relationship between mining and excavation, some coal mines have excavated the mining lanes of the next working face while the previous working face is being mined, that is, mining and excavation are carried out in parallel. Different from traditional tunnel excavation, when entering the tunnel with high extraction from the mining face, the tunnel will experience severe deformation during the whole process of breaking of the roof rock layer in the goaf of the upper section working face, rotation and sinking, and compaction and stabilization of the gangue, which will affect the normal advancement of the working face and the normal excavation of the tunnel, and greatly threaten the safety of mine production.

[0003] However, the current surrounding rock control technology for high-extraction tunnels facing mining still adopts a single support method, which has low support efficiency and high support cost. Therefore, for technical personnel in this field, in order to ensure safe production and improve mine production efficiency, how to improve the stability and tunnel control efficiency of high-extraction tunnels facing mining, and at the same time reduce the cost of high-extraction tunneling, is an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the present invention provides a method for segmented control of surrounding rock in a high-extraction tunnel facing mining, so as to solve the problems raised in the background technology.

[0005] In order to achieve the above-mentioned object, the present invention adopts the following technical solution: a method for segmented control of surrounding rock in high-extraction tunneling, the specific steps of which include the following:

[0006] By collecting relevant geological parameters of the high-extraction roadway and the mining face, and using the horizontal and vertical distances between the high-extraction roadway and the mining face, as well as the geological parameters of the strata in which they are located and the overlying strata, a numerical model of the high-extraction roadway under mining conditions was established.

[0007] Based on the mining stress and rock movement of the high-extraction tunnel, the whole process of high-extraction tunnel excavation is divided into four stages;

[0008] According to the surrounding rock stability of high-extraction tunnels at different stages, different support methods are used in each stage to control the tunnel surrounding rock.

[0009] Optionally, the geological model under the conditions of high-extraction tunnel excavation can be obtained through the stress distribution around the high-extraction tunnel and the mining working face, as well as the movement of rock formations during the high-extraction tunnel excavation and working face advancement.

[0010] Optionally, the mining stress and rock movement conditions of the high-extraction roadway include: the influence range of the support pressure in front of the working face and the influence range of the rock movement behind the working face; wherein:

[0011] The influence range of the supporting pressure in front of the working face includes: the mining stress influence area and the original rock stress area;

[0012] The scope of influence of rock strata movement behind the working face includes: roof rock strata collapse area and roof rock strata compaction area.

[0013] Optionally, the four stages are: leading dynamic pressure influence stage, dynamic pressure action stage, lagging dynamic pressure influence stage and lagging pressure stabilization stage, and the four stages correspond one-to-one to the influence range described in claim 4; wherein:

[0014] The advanced dynamic pressure influence section corresponds to the original rock stress zone;

[0015] The dynamic pressure action section corresponds to the stress increasing area;

[0016] The delayed dynamic pressure action section corresponds to the roof rock collapse zone;

[0017] The hysteresis pressure stabilization section corresponds to the top rock layer compaction area.

[0018] Optionally, the stability of the surrounding rock of the high-extraction tunnel at different stages includes: the stress level of the tunnel surrounding rock and the manifestation of mine pressure in the tunnel during the high-extraction tunnel excavation stage.

[0019] Optionally, the different support methods include: adopting anchor cables with different spacings according to the stability of the surrounding rock at different stages, and cooperating with W steel belts to achieve effective control of the surrounding rock.

[0020] Through the above technical solutions, it can be seen that compared with the existing technology, the present invention provides a method for segmented control of the surrounding rock of the high-extraction tunnel facing mining, which has the following beneficial technical effects: by establishing a mining operation model of the high-extraction tunnel and the facing mining working face, and using the mining stress and rock movement conditions of the high-extraction tunnel obtained, the whole process of high-extraction tunnel excavation is divided into four stages. And according to the stress of the tunnel surrounding rock and the mine pressure manifestation of the tunnel at each stage, each stage adopts its own effective support method to realize segmented control of the surrounding rock during the high-extraction tunnel facing mining. It realizes the reasonable segmentation of the high-extraction tunnel facing mining, and at the same time improves the efficiency of the high-extraction tunnel surrounding rock control, and can further reduce the tunnel excavation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0022] Figure 1 This is a flow chart of a method for controlling surrounding rock segments in a high-extraction tunnel facing mining according to the present invention;

[0023] Figure 2 This is a schematic diagram of the arrangement of layers of high-extraction roadway and coal mining working face of the present invention;

[0024] Figure 3 Schematic diagram of the numerical model of the high-extraction roadway under mining conditions of the present invention;

[0025] Figure 4 This is a curve diagram of the support pressure distribution in front of the working surface of the present invention;

[0026] Figure 5 This is a schematic diagram of the rock formation movement behind the working face of the present invention;

[0027] Figure 6 This is a schematic diagram of the high-extraction lane segmentation of the present invention;

[0028] Among them, 1 is the S5207 high-extraction tunnel, 2 is the S5206 working face, 3 is the S5206 section flat tunnel, 4 is the leading dynamic pressure influence section, 5 is the dynamic pressure action section, 6 is the lagging dynamic pressure influence section, 7 is the lagging pressure stabilization section, and 8 is the mining stress influence area. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] The embodiment of the present invention discloses a method for segmented control of surrounding rock in a high-extraction roadway during mining. The present invention will be described in detail below with reference to a specific example in which the S5207 high-extraction roadway in a mine is severely affected by the dynamic pressure of the S5206 working face during mining. The specific steps include the following:

[0031] Please refer to Figure 1 , Figure 1This is a flow chart of a method for controlling the surrounding rock of a high-pressure extraction tunnel facing mining provided by a specific embodiment of the present invention. The method for controlling the surrounding rock of a high-pressure extraction tunnel facing mining provided by this embodiment includes:

[0032] Step S1: By collecting relevant geological parameters of the S5207 high-extraction roadway and the S5206 working face, and using the horizontal and vertical distances between the high-extraction roadway and the mining working face, as well as the geological parameters of the stratum and overlying stratum, a numerical model of the high-extraction roadway under the mining excavation condition is established;

[0033] Specifically, such as Figure 2 、 Figure 3 As shown in the figure, according to the layout layers and relevant geological parameters of the S5207 high-extraction tunnel and the S5206 working face, a numerical model of the S5207 high-extraction tunnel under the mining and excavation conditions can be established.

[0034] Among them, the S5207 high-extraction tunnel and the S5206 working face are in a state of advancing towards each other.

[0035] Step S2: Based on the mining stress and rock movement of the high-extraction tunnel, the entire process of high-extraction tunnel excavation is divided into four stages.

[0036] During the forward advancement of the S5206 working face, stress-increasing areas will appear in front of and on the sides of the working face, such as Figure 4 As shown, the mining stress influence zone 8 can be obtained by the numerical model described in step S1. Similarly, behind the coal mining face, as shown in FIG. Figure 5 As shown, the immediate roof of the S5206 working face experienced regular and irregular collapses as mining progressed, leading to dramatic structural adjustments. Separation occurred between the key strata and the immediate roof, and the rock blocks in the key strata began to bend and sink, causing intense deformation pressure on the surrounding rock mass. Furthermore, when the S5207 high-extraction roadway was being excavated, it was inevitably affected by the aforementioned areas of increased mining stress and the intense deformation pressure caused by mining.

[0037] Based on the above basic principles, the support pressure distribution range in front of the S5206 working face can be divided into the mining stress increased zone and the original rock stress zone; the rock stratum movement influence range behind the S5207 working face can be divided into the roof rock stratum collapse zone and the roof rock stratum compaction zone.

[0038] Furthermore, the four areas determined above correspond to the four stages divided by the S5207 high-pressure extraction lane: leading dynamic pressure influence section 4, dynamic pressure action section 5, lagging dynamic pressure influence section 6 and lagging pressure stabilization section 7.

[0039] Among them, the leading dynamic pressure influence section 4 corresponds to the original rock stress zone; the dynamic pressure action section 5 corresponds to the stress increase zone 8; the lagging dynamic pressure action section 6 corresponds to the roof rock collapse zone; the lagging pressure stabilization section 7 corresponds to the roof rock compaction zone.

[0040] Specifically, such as Figure 6 As shown in the figure, the whole process of S5207 high-extraction tunnel excavation is divided into four stages.

[0041] In the advanced dynamic pressure influence section 4, when the high-extraction roadway is outside the mining stress influence zone in front of the S5206 working face, that is, when the S5207 high-extraction roadway driving head is 150m in front of the S5206 working face, that is, Figure 4 Outside the mining stress influence zone shown in the figure, it is divided into the advanced dynamic pressure influence section. During this stage, the tunnel excavation is basically unaffected by the mining stress influence zone ahead of the S5206 working face, the mine pressure in the tunnel is not obvious, and the surrounding rock of the high-pressure extraction tunnel is relatively easy to control.

[0042] Dynamic pressure action section 5 occurs when the high-pressure extraction tunnel is within the mining stress influence zone ahead of the S5207 working face. This section begins when the tunneling head of the S5207 high-pressure extraction tunnel enters within 150 meters ahead of the S5206 working face. During this stage, tunneling is affected by the increased stress zone ahead of the S5206 working face, increasing stress and deformation in the surrounding rock of the high-pressure extraction tunnel. When the two converge, the leading support pressure ahead of the tunnel reaches approximately 20 MPa.

[0043] The delayed dynamic pressure influence section 6, when the S5207 high extraction lane meets the S5206 working face, Figure 5 As shown, the overburden structure changes dramatically, and vertical stress increases sharply, reaching a maximum of 40 MPa. The roadway will be affected by unstable high stress. At this stage, the surrounding rock stress is intense and the surrounding rock is severely damaged. According to the numerical model and relevant mining data, the length of this section is 300 to 400 meters.

[0044] In the delayed pressure stabilization section 7, when the roof collapse caused by the mining of the S5206 working face is relatively complete, it has a supporting effect on the overlying rock strata, the key layer rock blocks no longer bend and sink, and the lateral support pressure is significantly reduced compared with the previous stage. The tunnel excavation is less affected by the roof movement, and the tunnel is in the lateral support pressure stable or even reduced area of the goaf in the upper section. Therefore, the tunnel stability is better in this stage and the tunnel is easy to control.

[0045] Step S3: Based on the surrounding rock stability at different stages of the high-pressure extraction tunnel, different support methods are used at each stage to control the tunnel surrounding rock.

[0046] Specifically, the surrounding rock stability and mine pressure manifestation of the high-pressure extraction tunnel in the four stages are classified according to different surrounding rock damage conditions.

[0047] From the support parameter simulation results of the numerical model in step S1 and combined with the actual production site, we can know that:

[0048] When the S5207 high-extraction tunnel is excavated in the leading dynamic pressure influence section and the lagging pressure stabilization section, the tunnel surrounding rock stress is low and the tunnel stability is good. A support method with a larger spacing can meet the requirements and save support material consumption.

[0049] When the S5207 high-extraction roadway is in the dynamic pressure action section, the roadway surrounding rock stress increases and the roadway deformation increases. It is necessary to adopt a larger spacing support method than the advanced dynamic pressure influence section to control the roadway surrounding rock. At the same time, the roadway excavation time in this stage is short and the support difficulty is not great.

[0050] When the S5207 high-pressure extraction tunnel is in the delayed dynamic pressure influence section, the stress of the surrounding rock of the high-pressure extraction tunnel increases again, and the deformation of the surrounding rock of the high-pressure extraction tunnel increases accordingly. The tunnel support parameters are optimized and screened in combination with the numerical model described in step S1. More reasonable support parameters need to be adopted for tunnel maintenance.

[0051] Specifically, the surrounding rock of the S5207 high-extraction tunnel is supported by a corresponding and reasonable support method.

[0052] in,

[0053] In the section affected by the advanced dynamic pressure, the roof support is constructed with anchor cables, a W-shaped anchor cable support plate, and a W-shaped steel belt assembly, with an anchor cable spacing of 1800mm x 1800mm. The sidewalls are supported with anchor rods and anchor rod trays, with an anchor rod spacing of 1800mm x 1800mm.

[0054] During the dynamic pressure section, the roof support is constructed with anchor cables, a W-shaped anchor support plate, and a W-shaped steel belt assembly, with a spacing of 1200mm x 1200mm between cables. The sidewalls are supported with anchor rods and anchor rod trays, with a spacing of 1200mm x 1200mm between rods.

[0055] For the section affected by delayed dynamic pressure, the support method for this stage was optimized based on numerical modeling. The top plate was supported by anchor cables, a combination of W-shaped anchor cable support plates and W-shaped steel strips, with a spacing of 900mm x 900mm between anchor cables. The sidewalls were supported by anchor rods and anchor rod trays, with a spacing of 900mm x 900mm between anchor rods.

[0056] For the delayed stabilization section, the roof support is constructed with anchor cables, a W-shaped anchor support plate, and a W-shaped steel strip, with a spacing of 1500mm x 1500mm between cables. The sidewalls are supported with anchor rods and anchor rod trays, with a spacing of 1500mm x 1500mm between rods.

[0057] It should also be noted that in the section affected by the delayed dynamic pressure, the prestressing force can be appropriately increased to further improve the support effect.

[0058] The above is a method for segmented control of surrounding rock in a high-extraction tunnel facing mining provided by the present invention.

[0059] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0060] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling surrounding rock in a mining tunnel by segmentation, characterized in that: The specific steps include the following: By collecting relevant geological parameters of the high-extraction roadway and the mining face, and using the horizontal and vertical distances between the high-extraction roadway and the mining face, as well as the geological parameters of the strata in which they are located and the overlying strata, a numerical model of the high-extraction roadway under mining conditions was established. Based on the mining stress and rock movement of the high-extraction tunnel, the whole process of high-extraction tunnel excavation is divided into four stages. According to the surrounding rock stability of the high-extraction tunnel at different stages, different support methods are used in each stage to control the tunnel surrounding rock. It is characterized in that the numerical model under the conditions of high-extraction roadway mining is used to obtain the stress distribution around the high-extraction roadway and the mining working face, as well as the movement of the rock formation during the high-extraction roadway excavation and working face advancement; The mining stress and rock movement conditions of the high-pressure extraction roadway include: the influence range of the support pressure in front of the working face and the influence range of the rock movement behind the working face, among which: The influence range of the supporting pressure in front of the working face includes: the mining stress influence area and the original rock stress area; The scope of influence of rock strata movement behind the working face includes: roof rock strata collapse area and roof rock strata compaction area; The four stages are: leading dynamic pressure influence section, dynamic pressure action section, lagging dynamic pressure influence section and lagging pressure stabilization section, and the four stages correspond one-to-one to the influence range, wherein: the leading dynamic pressure influence section corresponds to the original rock stress zone; the dynamic pressure action section corresponds to the mining stress influence zone; the lagging dynamic pressure action section corresponds to the roof rock collapse zone; the lagging pressure stabilization section corresponds to the roof rock compaction zone.

2. The method for controlling surrounding rock of a mining tunnel in sections according to claim 1 is characterized in that: The stability of the surrounding rock of the high-extraction tunnel at different stages includes: the stress level of the tunnel surrounding rock during the high-extraction tunnel excavation stage and the manifestation of the mine pressure in the tunnel.

3. The method for controlling surrounding rock of a mining tunnel in sections according to claim 1 is characterized in that: The different support methods include: adopting anchor cables with different spacings according to the stability of the surrounding rock at different stages, and cooperating with W steel belts to control the surrounding rock.

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