Coal mine tunnel supporting structure and construction method

Abstract

The invention discloses a coal mine roadway supporting structure and a construction method.The coal mine roadway supporting structure comprises a thin spraying layer and an anchor rod supporting assembly, the thin spraying layer covers the surface of a roadway, the anchor rod supporting assembly comprises a plurality of anchor rods arranged in multiple rows and multiple columns, and the anchor rods penetrate through the thin spraying layer and are anchored into a rock layer of the roadway; the anchor rods form a plurality of matrix groups, each matrix group comprises four adjacent anchor rods which are distributed in a rectangular shape, and a steel bar beam is connected between every two anchor rods which are distributed diagonally in each matrix group. According to the coal mine roadway supporting structure, unstable rock strata in surrounding rock can be bonded and wrapped in stable rock strata through the thin spraying layer, the temporary supporting effect is achieved, the X-shaped intersecting steel bar beams are arranged between the anchor rods distributed in a rectangular mode, the surrounding rock in a far area can be supported through the steel bar beams, the situation that the thin spraying layer is torn due to the fact that the deformation quantity of the surrounding rock is too large is avoided, and the supporting effect is good. The supporting effect is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine tunnel support devices, and in particular to a coal mine tunnel support structure and a construction method. Background Art

[0002] In tunnel support, metal mesh combined with anchor support is a common support method, but the laying of metal mesh requires manual hanging and connecting of the mesh, which cannot be completed automatically by equipment. The mechanization efficiency is low and cannot meet the requirements of intelligent mine excavation. In anchor support, the surrounding rock near the anchor is supported by the anchor preload, and the deformation of the surrounding rock is small, while the surrounding rock farther away from the anchor position still has a large deformation, which may cause safety problems due to local leakage. Summary of the invention

[0003] The present invention aims to solve the technical problems in the related technologies. To this end, an embodiment of the present invention proposes a coal mine tunnel support structure. The coal mine tunnel support structure can use a thin sprayed layer to bond and cover the unstable rock strata in the surrounding rock in the stable rock strata, thereby playing a role of temporary support. "X"-shaped intersecting steel beams are arranged between the rectangularly distributed anchor rods. The steel beams can be used to support the surrounding rock in a farther area, thereby avoiding excessive deformation of the surrounding rock and tearing the thin sprayed layer, thereby ensuring the support effect.

[0004] The coal mine tunnel support structure of the embodiment of the present invention includes a thin shotcrete layer and an anchor support assembly, wherein the thin shotcrete layer covers the surface of the tunnel, and the anchor support assembly includes a plurality of anchor rods arranged in multiple rows and columns, wherein the anchor rods pass through the thin shotcrete layer and are anchored into the rock layer of the tunnel, and the plurality of anchor rods form a plurality of matrix groups, each of the matrix groups includes four adjacent anchor rods distributed in a rectangular shape, and a steel beam is connected between two diagonally distributed anchor rods in the matrix group.

[0005] The coal mine tunnel support structure of the embodiment of the present invention comprises a thin sprayed layer covering the surface of the tunnel, the anchor support assembly comprises a plurality of anchors arranged in multiple rows and columns, the anchors pass through the thin sprayed layer and are anchored into the rock layer of the tunnel, and the plurality of anchors constitute a plurality of matrix groups, each of the matrix groups comprises four adjacent anchors distributed in a rectangular shape, a steel beam is connected between two anchors diagonally distributed in the matrix group, thereby the thin sprayed layer can bond and cover the unstable rock layer in the surrounding rock in the stable rock layer, thus playing a role of temporary support, and compared with laying metal mesh, the thin spraying operation is more efficient, and can be fully automated to save manpower, and in addition, "X"-shaped intersecting steel beams are arranged between the rectangularly distributed anchors, so that the steel beams can be used to support the surrounding rock in a farther area, thereby avoiding the surrounding rock from tearing the thin sprayed layer due to excessive deformation, thereby ensuring the support effect.

[0006] In some embodiments, the steel bars in different matrix groups with the same extension direction are the same

[0007] In some embodiments, the thin spray layer is provided with grouting holes.

[0008] In some embodiments, there are multiple grouting holes, and one grouting hole is provided at the intersection of the diagonals of the four anchor rods in each matrix group.

[0009] In some embodiments, the steel beam comprises two steel beams arranged at an interval, and the interval is used to avoid the grouting holes.

[0010] In some embodiments, the thickness d of the thin sprayed layer satisfies 5 mm ≤ d ≤ 10 mm.

[0011] The construction method of the coal mine tunnel support structure of the embodiment of the present invention, the coal mine tunnel support structure is the coal mine tunnel support structure according to claim 3, and the construction method comprises:

[0012] Thin shotcrete support is immediately carried out after excavation to form a thin shotcrete layer;

[0013] Lay anchor support components closely following the excavation working face;

[0014] Drill grouting holes on the thin spray layer and perform high-pressure grouting.

[0015] The construction method of the coal mine tunnel support structure of the embodiment of the present invention sequentially performs thin spraying, anchor protection and high-pressure grouting on the tunnel. The three processes work together to reduce the deformation of the surrounding rock and improve the long-term bearing capacity of the confining pressure.

[0016] In some embodiments, drilling grouting holes on the thin spray layer and performing high-pressure grouting includes:

[0017] High-pressure grouting is carried out at a distance not exceeding 100m from the lagging excavation working face.

[0018] In some embodiments, the construction method further includes: stopping grouting when the bulging amount of the thin sprayed layer exceeds 30 mm, waiting for 30 minutes and then grouting again, and the maximum bulging amount of the thin sprayed layer does not exceed 50 mm.

[0019] In some embodiments, the anchor support assembly laid immediately following the excavation working face includes:

[0020] Anchor bolts are placed in multiple rows and columns;

[0021] The steel beams are laid diagonally in a matrix of four adjacent anchor rods. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of a coal mine tunnel support structure according to an embodiment of the present invention.

[0023] Figure 2 It is a cross-sectional view of a coal mine tunnel support structure according to an embodiment of the present invention.

[0024] Reference numerals:

[0025] Anchor rod 1, steel beam 2, grouting hole 3, thin sprayed layer 4, surrounding rock 5. DETAILED DESCRIPTION

[0026] 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.

[0027] like Figure 1 and Figure 2 As shown, the coal mine tunnel support structure of the embodiment of the present invention includes a thin spray layer 4 and an anchor support assembly.

[0028] Specifically, the thin shotcrete layer 4 is coated on the surface of the tunnel, and the anchor support assembly includes a plurality of anchor rods 1 arranged in multiple rows and columns. The anchor rods 1 pass through the thin shotcrete layer 4 and are anchored into the rock layer of the tunnel, and the plurality of anchor rods 1 form a plurality of matrix groups, each matrix group includes four adjacent anchor rods 1 distributed in a rectangular shape, and a steel beam 2 is connected between two diagonally distributed anchor rods 1 in the matrix group.

[0029] Therefore, the present application adopts the thin-spraying process to form a thin-spraying layer 4 on the surface of the roadway, and the unstable rock layer in the surrounding rock 5 is bonded and coated in the stable rock layer, which plays a role of temporary support. As the surrounding rock 5 deforms, the thin-spraying support will inhibit the expansion of the cracks in the surrounding rock 5, isolate the water vapor in the roadway from the coal rock mass, reduce the weathering of the surrounding rock 5, and improve the long-term strength of the surrounding rock 5. Compared with laying metal mesh, the thin-spraying operation is more efficient, and can be fully automated, saving manpower.

[0030] In addition, the anchor rod 1 support of the present application adds a steel beam 2. Two steel beams 2 intersecting in an "X" shape are arranged in the matrix group composed of every four anchor rods 1. The surrounding rock 5 at a distance from the anchor rods 1 can be supported by the steel beams 2 to avoid local leakage, and the intersection point of the "X"-shaped intersecting steel beams 2 is opposite to the center of the matrix (the deformation of the surrounding rock 5 in this area is the largest), thereby avoiding excessive deformation in this area that leads to tearing of the thin sprayed layer 4, thereby ensuring the support effect.

[0031] In the coal mine tunnel support structure of the embodiment of the present invention, the thin spray layer 4 is coated on the surface of the tunnel, and the anchor support assembly includes a plurality of anchor rods 1 arranged in multiple rows and columns, the anchor rods 1 pass through the thin spray layer 4 and are anchored into the rock layer of the tunnel, and the plurality of anchor rods 1 constitute a plurality of matrix groups, each matrix group includes four adjacent anchor rods 1 distributed in a rectangular shape, and a steel beam 2 is connected between two anchor rods 1 distributed diagonally in the matrix group, thereby, the thin spray layer 4 can bond and coat the unstable rock layer in the surrounding rock 5 in the stable rock layer, playing a role of temporary support, and compared with laying metal mesh, the thin spray operation is more efficient, and can be fully automated to save manpower, and in addition, "X"-shaped intersecting steel beams 2 are arranged between the rectangularly distributed anchor rods 1, and the steel beams 2 can be used to support the surrounding rock 5 in a farther area, so as to avoid the surrounding rock 5 from tearing the thin spray layer 4 due to excessive deformation, thereby ensuring the support effect.

[0032] Furthermore, the steel beams 2 with the same extension direction in different matrix groups are the same. In other words, each steel beam 2 can be connected to multiple matrix groups in sequence.

[0033] Furthermore, the thin shotcrete 4 is provided with grouting holes 3. It should be noted that, in order to reduce the continuous deformation of the surrounding rock 5 and improve the self-bearing capacity of the surrounding rock 5, the grouting holes 3 provided on the thin shotcrete 4 can be used to perform high-pressure grouting in the coal rock mass, and the slurry penetrates into the larger cracks to reinforce the coal rock mass cracks. Under the action of high grouting pressure, the cracks that the slurry cannot penetrate into are squeezed and closed, thereby increasing the bearing capacity of the surrounding rock 5 and reducing the deformation of the roadway.

[0034] Optionally, the high-pressure grouting pressure is 15-20 MPa, and the grouting material is ultrafine cement with a particle size D95≤10 μm, which can penetrate into cracks with an opening greater than 15 μm. The high grouting pressure can squeeze and close cracks with an opening less than 15 μm, thereby improving the overall bearing capacity of the surrounding rock 5.

[0035] Furthermore, there are multiple grouting holes 3, and a grouting hole 3 is provided at the intersection of the diagonals of the four anchor rods 1 of each matrix group. It can be understood that, taking the rectangular anchor protection area formed by the four anchor rods 1 as an example, the position in the middle of the rectangular area is where the rock deformation is the largest and is most likely to have large cracks. This position corresponds to the intersection of the "X"-shaped steel beam 2. The grouting hole 3 is set here for high-pressure grouting, which can strengthen the rock mass in a targeted manner and reduce the deformation of the roadway.

[0036] Optionally, the steel bar beam 2 includes two steel bar beams arranged at an interval, and the interval is used to avoid the grouting holes 3.

[0037] Furthermore, the thickness d of the thin sprayed layer 4 satisfies 5mm≤d≤10mm, the bonding strength with the coal body is not less than 1.8MPa, and the elongation after fracture is not less than 70%, which can isolate the weathering effect of water vapor in the tunnel on the coal and rock bodies.

[0038] The construction method of the coal mine tunnel support structure of the embodiment of the present invention is the coal mine tunnel support structure of the above-mentioned embodiment, and the construction method includes: performing thin spraying support immediately after excavation to form a thin spraying layer 4; laying anchor support components immediately following the excavation working face; drilling grouting holes 3 on the thin spraying layer 4 and performing high-pressure grouting.

[0039] The construction method of the coal mine tunnel support structure of the embodiment of the present invention sequentially performs thin spraying, anchor protection and high-pressure grouting on the tunnel. The three processes work together to reduce the deformation of the surrounding rock 5 and improve the long-term bearing capacity of the confining pressure.

[0040] Further, drilling the grouting hole 3 on the thin sprayed layer 4 and performing high-pressure grouting includes:

[0041] High-pressure grouting is carried out at a distance not exceeding 100m from the lagging excavation working face.

[0042] Furthermore, the construction method also includes: stopping grouting when the bulging amount of the thin sprayed layer 4 exceeds 30 mm, waiting for 30 minutes and then grouting again, and the maximum bulging amount of the thin sprayed layer 4 does not exceed 50 mm.

[0043] Furthermore, the anchor support assembly laid immediately following the excavation working face includes:

[0044] Anchor bolts are placed in a multi-row and multi-column layout 1;

[0045] The steel beams 2 are laid along the diagonal line in a matrix group formed by four adjacent anchor rods 1 .

[0046] In the description of the present invention, it should 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", "axis", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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 coal mine tunnel support structure, characterized in that: It includes a thin sprayed layer and an anchor support assembly, wherein the thin sprayed layer covers the surface of the tunnel, and the anchor support assembly includes a plurality of anchor rods arranged in multiple rows and columns, the anchor rods pass through the thin sprayed layer and are anchored into the rock layer of the tunnel, and the plurality of anchor rods form a plurality of matrix groups, each of the matrix groups includes four adjacent anchor rods distributed in a rectangular shape, and a steel beam is connected between two diagonally distributed anchor rods in the matrix group.

2. The coal mine tunnel support structure according to claim 1, characterized in that: The steel bar beams with the same extension direction in different matrix groups are the same.

3. The coal mine tunnel support structure according to claim 1, characterized in that: The thin spray layer is provided with grouting holes.

4. The coal mine tunnel support structure according to claim 3, characterized in that: There are multiple grouting holes, and one grouting hole is provided at the intersection of the diagonals of the four anchor rods in each matrix group.

5. The coal mine tunnel support structure according to claim 4, characterized in that: The steel bar beam comprises two steel bar beams which are arranged at an interval, and the interval is used to avoid the grouting holes.

6. The coal mine tunnel support structure according to claim 1, characterized in that: The thickness d of the thin sprayed layer satisfies 5mm≤d≤10mm.

7. A construction method for a coal mine tunnel support structure, characterized in that: The coal mine tunnel support structure is the coal mine tunnel support structure according to claim 3, and the construction method comprises: Thin shotcrete support is immediately carried out after excavation to form a thin shotcrete layer; Lay anchor support components closely following the excavation working face; Drill grouting holes on the thin spray layer and perform high-pressure grouting.

8. The construction method of the coal mine tunnel support structure according to claim 7, characterized in that: The method of drilling grouting holes on the thin spray layer and performing high-pressure grouting comprises: High-pressure grouting is carried out at a distance not exceeding 100m from the lagging excavation working face.

9. The construction method of the coal mine tunnel support structure according to claim 8, characterized in that: Also includes: When the bulging volume of the thin sprayed layer exceeds 30mm, stop grouting, wait for 30 minutes and then grouting again. The maximum bulging volume of the thin sprayed layer shall not exceed 50mm.

10. The construction method of the coal mine tunnel support structure according to claim 7, characterized in that: The anchor support assembly for laying the following excavation working face comprises: Anchor bolts are placed in multiple rows and columns; The steel beams are laid diagonally in a matrix of four adjacent anchor rods.

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