Combined supporting method suitable for upper-layer mining access road and lower-layer undercutting ore removal access road of extremely-broken rock stratum powdery ore body

Abstract

The invention discloses a combined supporting method suitable for an upper-layer mining drift and a lower-layer undercutting ore removal drift of an extremely broken rock stratum powdery ore body, and relates to the field of mining drift supporting and reinforcing, and the mining drift comprises a first-step mining room drift and a second-step mining room drift which are arranged side by side at intervals; the mining method comprises the following steps: step 1, tunneling and supporting an access of a one-step mining room: firstly, forming an integrated support, secondly, after the integrated support is formed, and finally, forming a combined support by matching a filling pile below, a reinforcing layer in a grouting and cementing range with the integrated support on an upper layer; and step 2, tunneling and supporting the drift of the two-step mining room, wherein a complete combined support is established for adjacent rooms during one-step mining in the step 1. The structure is reasonable in layout, soft and broken surrounding rock can be effectively treated, tunneling safety is guaranteed, and the construction efficiency of a mining access road is improved.

Description

Technical Field

[0001] The invention relates to the field of mining access support and reinforcement, and in particular to a combined support method suitable for an upper mining access and a lower bottom mining access of extremely broken rock strata powdery ore bodies. Background Art

[0002] Due to the genesis of metal ore deposits, the ore body usually has a certain thickness, which is generally divided into multiple layers. It is mined layer by layer in an upward or downward direction, and mining and filling work is carried out in each layer using mining units such as pans and approaches. For thin ore bodies with small thickness, mining in the mine room usually adopts the method of excavating the mining approach in the upper layer and then excavating the bottom mining approach in the lower layer. Depending on the thickness of the ore body, the height of the bottom mining approach may reach more than 6m. Under the condition that the ore body and surrounding rock are severely broken, in order to ensure safety, steel arches and other supports are required in the mining approach. If steel arches are used to support the upper mining approach and the lower bottom mining approach of each step mining room, the cost is high and the efficiency of ore body mining is low.

[0003] Therefore, in view of the engineering characteristics of the upper mining access and the lower bottom mining access of the extremely broken rock strata and powdery ore bodies, effective management of the soft and broken surrounding rock, ensuring excavation safety, improving the construction efficiency of the mining access and reducing costs have become technical problems that technical personnel in this field need to solve urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a combined support method suitable for the upper mining approach and the lower bottom mining approach of extremely broken rock strata and powdery ore bodies. Based on the mining sequence of mining one by one in each mine room, the method can effectively control the soft and broken surrounding rock and powdery ore bodies, ensure the safety of the approach, reduce the difficulty of support operation construction, improve the efficiency of mining approach construction, reduce the steel arch support materials required for the approach support in each step of mining, and effectively reduce the construction cost.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The invention discloses a combined support method for an upper mining route and a lower bottom mining route of a powdered ore body in an extremely broken rock layer, wherein the mining route comprises a one-step mining chamber route and a two-step mining chamber route, wherein the one-step mining chamber route and the two-step mining chamber route are arranged side by side and at intervals; and the mining comprises the following steps:

[0007] Step 1: Excavation and support of the mining chamber access road:

[0008] First, the formation of integrated support, through the steel arch frame to complete the support of the mining approach of the upper ore body in one step; after multiple steel arch frames are supported, the steel arch frames and the upper floor are connected to each other through steel beams at the two sides of the approach and the upper floor, forming an integrated support;

[0009] Secondly, after the integrated support is formed, a perforated steel pipe is driven into the lower ore body from the position of the steel beam and fixed, and then grouting and reinforcement are performed to form a cast-in-place pile; at the same time, the slurry seeps out from the steel pipe hole, solidifies within the grouting bonding range, and reinforces the lower broken surrounding rock mass;

[0010] Finally, the cast-in-place piles and the reinforcement layer within the grouting bonding range below cooperate with the integrated support of the upper layer to form a combined support;

[0011] Step 2, excavation and support of the second-step mining chamber access road. The adjacent mining chamber established a complete joint support during the first-step mining of step 1, and reinforced the lower broken surrounding rock through external infiltration slurry. Therefore, the support of the second-step mining access road was completed by anchor rod and cable support method.

[0012] Preferably, the specific construction process of the steel arch support in step 1 includes the following steps:

[0013] S1. Construction preparation;

[0014] S2, excavation of the mining approach for the upper ore body in one step;

[0015] S3, steel arch support for the upper mining approach, after excavation to the designated position, multiple steel arches are arranged side by side to form a steel arch support;

[0016] S4, installing a steel beam one at both sides of the upper mining access road, wherein the steel beam one fixedly connects the plurality of steel arch frames together so that each independent steel arch frame forms a whole;

[0017] S5. A second steel beam is installed at the bottom plate of the upper mining access road to connect the steel arch frame, wherein the bottom plate of the upper mining access road is connected to the upper steel arch frame through the second steel beam, so that the steel arch frame and the bottom plate of the upper mining access road form a whole;

[0018] S6. Steel beams drive perforated steel pipes into the lower layer of the ore body, where the spacing of the perforated steel pipes is consistent with the spacing of the steel arches, the hole diameter meets the minimum limit for the passage of grouting liquid, and the length of the perforated steel pipe exceeds the bottom of the ore body, so that the cast-in-place piles pass through the lower ore body and reach the bottom plate of the mine access road;

[0019] S7. The top of the perforated steel pipe is connected and fixed to the steel beam, so that the cast-in-place pile and the steel arch frame form a whole;

[0020] S8, inject grout into the perforated steel pipe, arrange reinforcement, and form a cast-in-place pile after solidification;

[0021] S9, one-step mining of the lower layer to pull the bottom out of the mine tunnel and form the bottom plate of the lower mining access road;

[0022] S10, filling the first-stage mining chamber, after the first-stage mining is completed, the first-stage mining chamber is filled;

[0023] S11, second-step mining of the upper ore body mining approach excavation;

[0024] S12, second-step mining of upper ore body mining access support;

[0025] S13, second step mining of the lower ore body and support of the mine access road.

[0026] Preferably, in S3, the distance between two adjacent steel arch frames is set to 800-1000 mm.

[0027] Preferably, in S4, the height of the steel beam 1 from the bottom plate of the upper mining access is h = 400 ~ 1000mm, depending on the height of the upper ore body mining access; the length of the steel beam 1 is consistent with the spacing of the steel arch frame, wherein the fixing method of the steel arch frame depends on the on-site construction conditions; the width of the steel beam 1 is consistent with the width of the steel arch frame.

[0028] Preferably, in S5, the second steel beam should be buried in the upper mining access floor and fixedly connected to the upper mining access floor, and the fixing method of the two depends on the on-site construction conditions; the length of the second steel beam is consistent with the spacing of the steel arch frame, and the fixing method of the steel arch frame depends on the on-site construction conditions; the width of the second steel beam is consistent with the width of the steel arch frame.

[0029] Preferably, in S6, the upper hole diameter of the perforated steel pipe is φ20-25 mm, and the diameter of the steel pipe is smaller than the width of the steel beam; the length of the perforated steel pipe depends on the height of the access route, and should satisfy the requirement that the upper end of the perforated steel pipe is fixed to the steel beams described in S4 and S5, and the lower end of the perforated steel pipe is driven into the bottom plate of the one-step mining access route in S9.

[0030] Preferably, in S7, the perforated steel pipe is fixed to the steel beam in S4 and the steel beam in S5, and the fixing method depends on the on-site construction conditions; in S8, the grouting pressure of the grouting is set to 2-3 MPa.

[0031] Preferably, in S11, the support of the second-step mining upper ore body approach is mainly completed by the existing support of the adjacent first-step mining chamber approach supplemented by anchor rods or anchor cables, and the anchor rods or anchor cables are radially distributed on the arc-shaped top of the approach.

[0032] Preferably, in S12, after the second-step mining lower ore body is pulled out of the mine through the bottom mining access road, its support is completed by the cast-in-place piles in the first-step mining chamber access road, and no additional support is required.

[0033] Preferably, in S6, the upper holes of the perforated steel pipe are arranged in multiple rows in the radial direction and distributed in a circular pattern, and are distributed at equal intervals in the axial direction.

[0034] Compared with the prior art, the beneficial technical effects of the present invention are:

[0035] The present invention discloses a combined support method suitable for the upper mining approach and the lower bottom mining approach of extremely broken rock strata powdery ore bodies. Based on the mining sequence of mining one by one in every other mine room, the method can effectively control the weak and broken surrounding rock and powdery ore bodies, ensure the safety of the approach, reduce the construction difficulty of the support operation, improve the construction efficiency of the mining approach, and at the same time reduce the steel arch support materials required for the approach support in each step of mining, effectively reducing the construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described below in conjunction with the accompanying drawings.

[0037] Figure 1 The flowchart of the combined support method of the present invention is applicable to the upper mining route and the lower bottom mining route of extremely broken rock powder ore body;

[0038] Figure 2 - Figure 3 This is a schematic diagram of the support of the upper mining route in one step of the present invention;

[0039] Figure 4 - Figure 5 This is a schematic diagram of the support of the entry road for pulling out the bottom of the ore in one step mining of the present invention;

[0040] Figure 6 It is a schematic diagram of the joint support formation of adjacent mine rooms in the present invention;

[0041] Explanation of reference numerals: 1. steel arch frame; 2. access road; 3. steel beam 1; 4. cast-in-place pile; 5. grouting bonding range; 6. first-step mining filling body; 7. second-step mining anchor rod or anchor cable support; 8. upper mining access road bottom plate; 9. lower mining access road bottom plate; 10. steel beam 2;

[0042] 201. One-step access to the mining chamber; 202. Two-step access to the mining chamber. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] like Figure 1-6 As shown, a combined support method for the upper mining route and the lower bottom mining route of extremely broken rock powder ore bodies, the mining route includes a one-step mining chamber route 201 and a two-step mining chamber route 202, the one-step mining chamber route 201 and the two-step mining chamber route 202 are arranged side by side at intervals; mining includes the following steps:

[0045] Step 1, excavation and support of the mining chamber approach 201:

[0046] First, the formation of integrated support, through the steel arch frame 1 to complete the support of the mining approach of the upper ore body in one step; after multiple steel arch frames 1 are supported, the steel arch frames and the upper floor are connected to each other through steel beams at the two sides of the approach and the upper floor, forming an integrated support;

[0047] Secondly, after the integrated support is formed, a perforated steel pipe is driven into the lower ore body from the position of the steel beam 3 and fixed, and then grouting and reinforcement are performed to form a cast-in-place pile 4; at the same time, the slurry seeps out from the steel pipe hole, solidifies within the grouting bonding range 5, and reinforces the lower broken surrounding rock mass;

[0048] Finally, the cast-in-place piles 4 below, the reinforcement layer of the grouting bonding range 5 and the integrated support of the upper layer cooperate with each other to form a combined support;

[0049] Step 2, excavation and support of the second-step mining chamber access road 202. The adjacent mining chambers established a complete joint support during the first-step mining of step 1, and reinforced the lower broken surrounding rock through external infiltration slurry. Therefore, the support of the second-step mining access road was completed by anchor rod and cable support method.

[0050] Specifically, the steel arch support in step 1 includes the following steps:

[0051] S1. Construction preparation;

[0052] S2, excavation of the mining approach for the upper ore body in one step;

[0053] S3, steel arch support of the upper mining approach, after excavation to the designated position, multiple steel arches 1 are arranged side by side to form a steel arch support;

[0054] S4, installing steel beams 3 at both sides of the upper mining access road, wherein the steel beams 3 connect the plurality of steel arch frames 1 together so that each independent steel arch frame forms a whole;

[0055] S5. The upper mining access floor plate is provided with a second steel beam 10 connected to the steel arch frame 1, wherein the upper mining access floor plate 8 is connected to the upper steel arch frame 1 through the second steel beam 10, so that the steel arch frame and the upper mining access floor plate 8 form a whole; specifically, the first steel beam and the second steel beam 2 are arranged in parallel up and down, and the upper mining access floor plate 8 is the upper floor plate;

[0056] S6. Steel beams drive perforated steel pipes into the lower layer of the ore body, where the spacing of the perforated steel pipes is consistent with the spacing of the steel arches, the hole diameter meets the minimum limit for the passage of grouting liquid, and the length of the perforated steel pipe exceeds the bottom of the ore body, so that the cast-in-place piles pass through the lower ore body and reach the bottom plate of the mine access road;

[0057] S7, the top of the perforated steel pipe is connected and fixed to the steel beam 3, so that the cast-in-place pile and the steel arch frame form a whole;

[0058] S8, injecting grout into the perforated steel pipe and arranging reinforcement, and forming a cast-in-place pile 4 after solidification;

[0059] S9, excavating the lower layer mining tunnel in one step and forming the lower mining access road floor 9;

[0060] S10, filling the first-stage mining chamber, after the first-stage mining is completed, the first-stage mining chamber is filled;

[0061] S11, second-step mining of the upper ore body mining approach excavation;

[0062] S12, second-step mining of upper ore body mining access support;

[0063] S13, second step mining of the lower ore body and support of the mine access road.

[0064] In S3, the distance between two adjacent steel arch frames 1 is set to 800-1000 mm.

[0065] In S4, the height of the steel beam 3 from the bottom plate 8 of the upper mining access is h=400~1000mm, which depends on the height of the upper ore body mining access; the length of the steel beam 3 is consistent with the spacing of the steel arch frame, wherein the fixing method of the steel arch frame depends on the on-site construction conditions; the width of the steel beam 3 is consistent with the width of the steel arch frame 1.

[0066] In S5, the steel beam 10 should be buried in the upper mining access floor 8 and fixedly connected to the upper mining access floor 8, and the fixing method of the two depends on the on-site construction conditions; the length of the steel beam 10 is consistent with the spacing of the steel arch frame, and the fixing method of the steel arch frame depends on the on-site construction conditions; the width of the steel beam 10 is consistent with the width of the steel arch frame.

[0067] In S6, the upper hole diameter of the perforated steel pipe is φ20~25mm, and the diameter of the steel pipe is smaller than the width of the steel beam; the length of the perforated steel pipe depends on the height of the access route, and should meet the requirements that the upper end of the perforated steel pipe is fixed to the steel beams described in S4 and S5, and the lower end of the perforated steel pipe is driven into the bottom plate of the one-step mining access route in S9.

[0068] In S7, the perforated steel pipe is fixed to the steel beam in S4 and the steel beam in S5, and the fixing method depends on the on-site construction conditions; in S8, the grouting pressure of the grouting is set to 2-3MPa to ensure that the grouting is in place, and the cast-in-place piles provide sufficient supporting force to ensure the stability and safety of the support.

[0069] In S11, the support of the second-step mining upper ore body approach is mainly completed through the existing support of the adjacent first-step mining chamber approach supplemented by anchor rods or anchor cables, and the anchor rods or anchor cables are distributed in a radial shape at the arc-shaped top of the approach.

[0070] In S12, after the second-step mining lower ore body is pulled out of the mine, its support is completed by the cast-in-place piles in the first-step mining chamber access, and no additional support is required; this shared construction method greatly reduces the steel arch support materials required for the access support in each step of mining, effectively reducing construction costs.

[0071] In S6, the upper holes of the perforated steel pipe are arranged in multiple rows in the radial direction and are distributed in a circumferential manner, and are distributed at equal intervals in the axial direction. In a specific embodiment, two, three or four holes are arranged in each row, and are arranged at intervals of 200mm, 250mm, 300mm, 350mm, 400mm, 450mm or 500mm in the axial direction. The hole positions can also be processed according to actual needs, wherein the regular arrangement facilitates processing, and the design of the upper holes is conducive to slurry extravasation.

[0072] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including 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.

[0073] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A combined support method for the upper mining route and the lower mining route of extremely broken rock powder ore bodies, characterized by: The mining approach comprises a first-step mining chamber approach (201) and a second-step mining chamber approach (202), wherein the first-step mining chamber approach (201) and the second-step mining chamber approach (202) are arranged side by side and spaced apart; The mining process includes the following steps: Step 1, excavation and support of the first-stage mining room approach (201): First, the formation of integrated support, through the steel arch frame (1) to complete the support of the mining route of the upper ore body in one step; after multiple steel arch frames (1) are supported, the steel arch frames and the upper floor are connected to each other at the two sides of the route and the upper floor through steel beams to form an integrated support; Secondly, after the integrated support is formed, a perforated steel pipe is driven into the lower ore body from the position of the steel beam and fixed, and then grouting and reinforcement are performed to form a cast-in-place pile (4); at the same time, the slurry seeps out from the steel pipe hole, solidifies within the grouting bonding range (5) and reinforces the lower broken surrounding rock mass; Finally, the cast-in-place piles (4) below, the reinforcement layer of the grouting bonding range (5) and the integrated support of the upper layer cooperate with each other to form a combined support; Step 2, excavation and support of the second-step mining chamber access road (202), the adjacent mining chambers established a complete joint support during the first-step mining of step 1, and the lower broken surrounding rock was reinforced by external infiltration slurry, so the support of the second-step mining access road was completed by anchor rod and cable support method.

2. The combined support method for the upper mining route and the lower bottom mining route of extremely broken rock powder ore bodies according to claim 1 is characterized by: The specific construction process of the steel arch support in step 1 includes the following steps: S1. Construction preparation; S2, excavation of the mining approach for the upper ore body in one step; S3, steel arch support for the upper mining access road, after excavation to the designated position, multiple steel arches (1) are arranged side by side to form a steel arch support; S4, installing steel beams (3) at both sides of the upper mining access road, wherein the steel beams (3) connect the plurality of steel arch frames (1) together so that the independent steel arch frames form a whole; S5, installing a second steel beam (10) at the upper mining access floor to connect the steel arch frame (1), wherein the upper mining access floor (8) is connected to the upper steel arch frame (1) through the second steel beam (10), so that the steel arch frame and the upper mining access floor (8) form a whole; S6. Steel beams drive perforated steel pipes into the lower layer of the ore body, where the spacing of the perforated steel pipes is consistent with the spacing of the steel arches, the hole diameter meets the minimum limit for the passage of grouting liquid, and the length of the perforated steel pipe exceeds the bottom of the ore body, so that the cast-in-place piles pass through the lower ore body and reach the bottom plate of the mine access road; S7. The top of the perforated steel pipe is connected and fixed to the steel beam, so that the cast-in-place pile and the steel arch frame form a whole; S8, injecting grout into the perforated steel pipe and arranging reinforcement, and forming a cast-in-place pile after solidification (4); S9, excavating the lower layer mining tunnel in one step and forming the lower mining access road floor (9); S10, filling the first-stage mining chamber, after the first-stage mining is completed, the first-stage mining chamber is filled; S11, second-step mining of the upper ore body mining approach excavation; S12, second-step mining of upper ore body mining access support; S13, second step mining of the lower ore body and support of the mine access road.

3. The combined support method for the upper mining route and the lower mining route of the extremely broken rock layer powder ore body according to claim 2 is characterized by: In S3, the distance between two adjacent steel arch frames (1) is set to 800-1000 mm.

4. The combined support method for the upper mining route and the lower bottom mining route of extremely broken rock powder ore bodies according to claim 2 is characterized by: In S4, the height of the steel beam 1 (3) from the bottom plate (8) of the upper mining access road is h = 400-1000 mm, depending on the height of the upper ore body mining access road; the length of the steel beam 1 (3) is consistent with the spacing of the steel arch frame, wherein the fixing method of the steel arch frame depends on the on-site construction conditions; the width of the steel beam 1 (3) is consistent with the width of the steel arch frame (1).

5. The combined support method for the upper mining route and the lower bottom mining route of extremely broken rock powder ore bodies according to claim 2 is characterized by: In S5, the second steel beam (10) should be buried in the upper mining access floor (8) and fixedly connected to the upper mining access floor (8), and the fixing method of the two depends on the on-site construction conditions; the length of the second steel beam (10) is consistent with the spacing of the steel arch frame, and the fixing method with the steel arch frame depends on the on-site construction conditions; the width of the second steel beam (10) is consistent with the width of the steel arch frame.

6. The combined support method for the upper mining route and the lower mining route of the extremely broken rock layer powder ore body according to claim 2 is characterized by: In S6, the hole diameter of the upper part of the perforated steel pipe is φ20-25 mm, and the diameter of the steel pipe is smaller than the width of the steel beam; the length of the perforated steel pipe depends on the height of the access road, and should be able to ensure that the upper end of the perforated steel pipe is fixed to the steel beam 1 (3) in S4 and the steel beam 2 (10) in S5, and the lower end of the perforated steel pipe is driven into the bottom plate (9) of the lower mining access road in S9.

7. The combined support method for the upper mining route and the lower mining route of the extremely broken rock layer powder ore body according to claim 2 is characterized by: In S7, the perforated steel pipe is fixed to the steel beam in S4 and the steel beam in S5, and the fixing method depends on the on-site construction conditions; in S8, the grouting pressure of the grouting is set to 2-3 MPa.

8. The combined support method for the upper mining route and the lower mining route of the extremely broken rock layer powder ore body according to claim 2 is characterized by: In S11, the support of the second-step mining upper ore body approach is mainly completed through the existing support of the adjacent first-step mining chamber approach supplemented by anchor rods or anchor cables, and the anchor rods or anchor cables are distributed in a radial shape at the arc-shaped top of the approach.

9. The combined support method for the upper mining route and the lower mining route of the extremely broken rock layer powder ore body according to claim 2 is characterized by: In S12, after the second-step mining of the lower ore body and the bottom mining access road are excavated, its support is completed by the cast-in-place piles in the first-step mining chamber access road, and no additional support is required.

10. The combined support method for the upper mining route and the lower mining route of the extremely broken rock layer powder ore body according to claim 2 is characterized by: In S6, the upper holes of the perforated steel pipe are arranged in multiple rows in the radial direction and distributed in a circumferential manner, and are distributed at equal intervals in the axial direction.

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