A combined support method for the upper mining route and the lower bottom mining route of extremely broken rock strata and powdered ore bodies

Abstract

The present invention discloses a combined support method for an upper mining approach and a lower bottom mining approach suitable for extremely broken rock strata powdered ore bodies, relating to the field of mining approach support and reinforcement. The mining approach includes a one-step mining chamber approach and a two-step mining chamber approach, which are arranged side by side and spaced apart. The mining process includes the following steps: Step 1: excavation and support of the one-step mining chamber approach, firstly, forming an integrated support, then, after the integrated support is formed, finally, the lower reinforced layer of cast-in-place piles and grouting cementation cooperates with the upper integrated support to form a combined support; Step 2: excavation and support of the two-step mining chamber approach, wherein adjacent chambers establish a complete combined support during the first-step mining. The present invention has a reasonable layout, can effectively treat weak and broken surrounding rock, ensures excavation safety, and improves the construction efficiency of the mining approach.

Description

Technical Field

[0001] The present 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 powdered 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. Mining is carried out 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 panels and approaches. For thin ore bodies with smaller thickness, mining in the mine room usually adopts the method of excavating the upper mining approach and then excavating the lower bottom mining approach. Depending on the thickness of the ore body, the height of the bottom mining approach may reach more than 6m. Under the condition of severe fragmentation of the ore body and surrounding rock, steel arches and other supports are required in the mining approach to ensure safety. 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 approach and the lower bottom mining approach in extremely broken rock strata and powdery ore bodies, effective management of the weak and broken surrounding rock, ensuring excavation safety, improving the construction efficiency of the mining approach, and reducing costs have become technical problems that technical personnel in this field urgently need to solve. Summary of the Invention

[0004] The purpose of the present invention is to provide a combined support method 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 ore chamber, the method can effectively control the weak 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 supporting the approach at each step of mining, and effectively reduce construction costs.

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

[0006] The present invention provides a combined support method for an upper mining approach and a lower bottom mining approach for extremely broken rock strata powdered ore bodies. The mining approach comprises a one-step mining chamber approach and a two-step mining chamber approach, and the one-step mining chamber approach and the two-step mining chamber approach are arranged side by side and spaced apart. Mining comprises the following steps:

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

[0008] First, the formation of integrated support, through the use of steel arches to complete the support of the upper mining approach; after the multiple steel arches are supported, the steel arches and the upper floor are connected together by steel beams at the two sides of the approach and the upper floor to form an integrated support;

[0009] Secondly, after the integrated support is formed, a perforated steel pipe is driven from the steel beam position to the lower ore body and fixed, followed by grouting and reinforcement to form a cast-in-place pile; at the same time, the slurry seeps out of the steel pipe holes, 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 approach. 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 chamber approach was completed using the anchor rod and cable support method.

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

[0013] S1. Construction preparation;

[0014] S2. Excavation of upper mining access road;

[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 steel beams one at both sides of the upper mining access road, wherein the steel beams one fixedly connect the plurality of steel arches together, so that the independent steel arches form a whole;

[0017] S5. Install a second steel beam at the upper mining access floor to connect the steel arch frame. The upper mining access floor is connected to the upper steel arch frame via the second steel beam, so that the steel arch frame and the upper mining access floor form a whole.

[0018] S6. Steel beams are driven into perforated steel pipes toward the lower layer of the ore body. The spacing of the perforated steel pipes is consistent with the spacing of the steel arches, and the hole diameter meets the minimum limit for the passage of grouting liquid. The length of the perforated steel pipes 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 mining 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, grouting and reinforcing the perforated steel pipe to form a cast-in-place pile after solidification;

[0021] S9, one-step mining of the lower layer and excavation of the mine roadway to form the lower mining access floor;

[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 approach 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 arches 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 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 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 two 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 φ20~25mm, 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 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 at the arc-shaped top of the approach.

[0032] Preferably, in S12, after the second-step mining lower layer ore body is pulled out of the mine access road, its support is completed by the cast-in-place piles in the first-step mining room 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 circumferentially, and are distributed at equal intervals in the axial direction.

[0034] Compared with the prior art, the present invention has the following beneficial technical effects:

[0035] The present invention discloses a combined support method 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 every other ore chamber, the method can effectively control the weak 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, and at the same time reduce the steel arch support materials required for supporting the approach at each step of mining, thereby effectively reducing construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0037] Figure 1 This is a flow chart of the combined support method for the upper mining route and the lower bottom mining route of extremely broken rock strata powdered ore bodies according to the present invention;

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

[0039] Figure 4 - Figure 5 This is a schematic diagram of the support for the bottom mining route of the present invention;

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

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

[0042] 201. One-step mining chamber entrance; 202. Two-step mining chamber entrance. 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 with reference to 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 intended to limit the present invention.

[0044] like Figure 1-6 As shown, a combined support method for the upper mining approach and the lower bottom mining approach for extremely broken rock strata powdered ore bodies is provided. The mining approach includes a one-step mining chamber approach 201 and a two-step mining chamber approach 202, which are arranged side by side at intervals. The mining process includes the following steps:

[0045] Step 1: Excavation and support of the one-step mining chamber approach 201:

[0046] First, the formation of integrated support, through the steel arch frame 1 to complete the support of the upper mining approach; after the 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 to form an integrated support;

[0047] Secondly, after the integrated support is formed, a perforated steel pipe is driven from the steel beam 3 to the lower ore body and fixed, followed by grouting and reinforcement to form a cast-in-place pile 4; at the same time, slurry seeps out of the steel pipe holes, 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] In step 2, excavation and support of the second-step mining chamber approach 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 seepage slurry. Therefore, the support of the second-step mining chamber approach was completed using the 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 upper mining access road;

[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. Install steel beams 3 at both sides of the upper mining access road. The steel beams 3 securely connect the multiple steel arches 1 together, so that the independent steel arches form a whole.

[0055] S5. Install the second steel beam 10 at the upper mining access floor position to connect with the steel arch frame 1. 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. Specifically, the first steel beam and the second steel beam are arranged parallel to each other, and the upper mining access floor 8 is the upper floor.

[0056] S6. Steel beams are driven into perforated steel pipes toward the lower layer of the ore body. The spacing of the perforated steel pipes is consistent with the spacing of the steel arches, and the hole diameter meets the minimum limit for the passage of grouting liquid. The length of the perforated steel pipes 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 mining 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, grouting and reinforcing the perforated steel pipe to form a cast-in-place pile 4 after solidification;

[0059] S9, one-step mining of the lower layer and excavation of the mine roadway to form the lower mining access 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 approach 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 arches 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 road is h = 400 ~ 1000 mm, which depends on the height of the upper ore body mining access road; 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 2 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 2 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 steel beam 2 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 be able to ensure 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 beams in S4 and S5, and the fixing method depends on the on-site construction conditions; in S8, the grouting pressure is set to 2-3 MPa to ensure that the grouting is in place, and the cast-in-place piles provide sufficient supporting force to ensure support stability and safety.

[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 top of the approach.

[0070] 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 bored piles in the first-step mining chamber access road, without the need for additional support; this shared construction method greatly reduces the steel arch support materials required for supporting the access roads in each step of mining, effectively reducing construction costs.

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

[0072] It should be noted that, in this document, relational terms such as first and second, etc., 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 variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0073] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A combined support method for the upper mining route and the lower bottom mining route of extremely broken rock strata and powdered ore bodies, characterized by: The mining approach includes a first-step mining chamber approach (201) and a second-step mining chamber approach (202), and the first-step mining chamber approach (201) and the second-step mining chamber approach (202) are arranged side by side at intervals; The mining process includes the following steps: Step 1, Excavation and support of the one-step mining chamber approach (201): First, the formation of an integrated support, through the steel arch frame (1) to complete the support of the upper mining approach; after the plurality of 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; 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 bored pile (4). The length of the perforated steel pipe exceeds the bottom of the ore body, so that the bored pile passes through the lower ore body and reaches the bottom plate of the mining access road; at the same time, the slurry seeps out of 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; In step 2, the excavation and support of the second-step mining chamber approach (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 seepage slurry, so the support of the second-step mining chamber approach was completed by the anchor rod and anchor cable support method; after the second-step mining lower ore body bottom mining approach was excavated, its support was completed by the cast-in-place piles in the first-step mining chamber approach, and no additional support was required.

2. The combined support method for the upper mining route and the lower bottom mining route of extremely broken rock strata powdered 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 upper mining access; S3, steel arch support for 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; S4, installing steel beams (3) at both sides of the upper mining access road, wherein the steel beams (3) fixedly 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 are driven into perforated steel pipes toward the lower layer of the ore body. The spacing of the perforated steel pipes is consistent with the spacing of the steel arches, and the hole diameter meets the minimum limit for the passage of grouting liquid. The length of the perforated steel pipes 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 mining 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, grouting and reinforcing the perforated steel pipe to form a cast-in-place pile (4) after solidification; S9, one-step mining of the lower layer and excavation of the mine tunnel to form 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 approach 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 bottom mining route of extremely broken rock strata powdered ore bodies according to claim 2 is characterized by: In S3, the distance between two adjacent steel arches (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 strata powdered ore bodies according to claim 2 is characterized by: In S4, the height of the steel beam (3) from the upper mining access floor (8) is h = 400 to 1000 mm, depending 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).

5. The combined support method for the upper mining route and the lower bottom mining route of extremely broken rock strata powdered ore bodies according to claim 2 is characterized by: In S5, the second steel beam (10) should be embedded 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 of the two 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 bottom mining route of extremely broken rock strata powdered ore bodies according to claim 2 is characterized by: In S6, the diameter of the upper hole 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 road, and should meet the requirements 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 upper mining access and lower bottom mining access in extremely broken rock strata powdered ore bodies 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 upper mining access and lower bottom mining access in extremely broken rock strata powdered ore bodies 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 top of the approach.

9. The combined support method for upper mining access and lower bottom mining access in extremely broken rock strata powdered ore bodies 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 circumferentially, and are distributed at equal intervals in the axial direction.

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