Safe and efficient stoping and supporting method suitable for silty soft ore body
By using an integrated support structure of advanced pipe roof grouting and cast-in-place piles, the problem of poor bearing capacity of silty and weak ore bodies during mining was solved, achieving efficient and safe ore body mining and support, and reducing construction costs and complexity.
Patent Information
- Application Number
- CN202610145612.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-02
- Publication Date
- 2026-03-10
AI Technical Summary
During the mining process, silty and weak ore bodies have poor bearing capacity, resulting in low mining efficiency, complicated and costly support construction, especially in local areas of the ore-rock contact zone.
An integrated support structure combining advanced pipe roof grouting support with cast-in-place piles is adopted. By installing cast-in-place piles and grouting at both sides of the approach, an integrated support structure is formed. Combined with anchor bolt and cable support, the lower ore body is gradually reinforced through layered mining to form a stable surrounding rock environment.
It improves mining efficiency, reduces support and backfilling costs, simplifies construction procedures, provides a stable surrounding rock environment, and enhances the safety and efficiency of ore body mining.
Smart Images
Figure CN121630443A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of mineral resource recovery technology, and in particular relates to a safe and efficient recovery and support method suitable for silty and weak ore bodies. Background Technology
[0002] Metallic ore deposits typically have a certain thickness due to their geological formation, and are usually divided into multiple layers. Mining is carried out layer by layer, either upwards or downwards, with each layer being mined and backfilled using panels, access roads, or other mining units. For some ore bodies, due to factors such as occurrence conditions, prior mining disturbance, and tectonic activity, their fracturing gradually intensifies, exhibiting silty characteristics and extremely poor bearing capacity. This phenomenon is particularly severe in localized areas of the ore-rock contact zone. Under these surrounding rock conditions, the depth of mining is severely limited, resulting in low recovery efficiency, cumbersome support construction procedures, and high costs.
[0003] Therefore, given the engineering characteristics of tunneling and ore body recovery in silty and weak ore bodies, effectively managing the silty and weak surrounding rock, ensuring tunneling safety, improving the construction efficiency of mining routes, and reducing costs are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention
[0004] The purpose of this invention is to provide a safe and efficient mining and support method suitable for silty and weak ore bodies, so as to solve the problems existing in the prior art.
[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides a safe and efficient mining and support method suitable for silty and weak ore bodies, comprising the following steps: S1, Preparation for the first strata of mining; S2, one-step mining approach support, tunneling, auxiliary support and mining; S3. Install grouting piles on both sides of the one-step mining approach to the next layer of ore body; S4, one-step mining and backfilling; S5, two-step mining approach support, tunneling, auxiliary support, mining and backfilling; S6. Preparation for the second-layer mining; S7. One-step mining of the upper access road, auxiliary support, mining, and backfilling; S8. One-step lower-level tunneling and mining; S9. Install grouting piles on both sides of the bottom access road of the lower ore body in the first mining step, and then install grouting piles on the next layer of ore body. S10, One-step mining of the lower ore body access and filling; S11, two-step mining upper approach tunneling, auxiliary support, mining and backfilling; S12, two-step mining lower access tunneling, mining and backfilling; S13, Preparations for subsequent stratified mining.
[0006] Optionally, the cast-in-place piles in steps S3 and S9 include driving perforated steel pipes into the next layer of ore body, with the perforated steel pipes connected and fixed by steel beams, and the perforated steel pipes being grouted and reinforced to form the cast-in-place piles.
[0007] Optionally, the diameter of the perforated steel pipe is 80mm~100mm, and the length of the perforated steel pipe is determined by the height of the next mining layer, requiring it to extend from 1m above the bottom plate of the current construction layer to the bottom plate of the next layer.
[0008] Optionally, the spacing between adjacent perforated steel pipes is 800mm to 1000mm.
[0009] Optionally, the height of the steel beam from the bottom plate is 400mm to 1000mm, the length of the steel beam is the same as the spacing between the perforated steel pipes, and the width of the steel beam is the same as the diameter of the perforated steel pipes.
[0010] Optionally, the diameter of the perforated steel pipe is φ20mm-25mm.
[0011] Optionally, the first-step mining access support and the second-step mining access support are advanced pipe roof grouting support.
[0012] Optionally, in steps S2, S5, S7 and S11, the upper access road of the first-step mining and the upper access road of the second-step mining are excavated by blasting, with the access road excavation face as the free face, and holes are drilled and explosives are loaded in the horizontal direction.
[0013] Optionally, in steps S8 and S12, the excavation of the first-step lower access road and the second-step lower access road is carried out by blasting, with the bottom plate of the first-step lower access road and the bottom plate of the second-step lower access road as free surfaces, and holes are drilled and explosives are loaded in the vertical direction.
[0014] Optionally, the grouting pressure for the advanced pipe roof grouting is determined by the length of the pipe roof.
[0015] This invention discloses the following technical effects: Due to the weak and silty surrounding rock of the roof, the first layer has a relatively small height. Roof support for the first layer of ore body mining is achieved through advanced pipe roof grouting, and the mining is carried out in a "one-off" manner. During the excavation of the one-step mining approach, cast-in-place piles are installed on both sides of the approach to the lower ore body; simultaneously, grout seeps from the steel pipe holes, cementing the weak and silty ore body of the lower layer, ultimately forming an integrated support structure with the cast-in-place piles and steel beams, providing a stable surrounding rock environment for the mining of the lower ore body.
[0016] During the mining of the second stratum and subsequent lower strata, the backfill material of the upper-level access road serves as the roof. Due to its superior integrity and bearing capacity compared to silty, weak rock, the access road can be supported using a lower-cost bolt and cable support method. Furthermore, because of the integrated structure formed by the grouting piles driven from the upper layer, starting from the second stratum, each stratum can be mined at a greater height, with separate upper and lower sections for mining. After mining, the entire height is backfilled in one go, improving mining efficiency while reducing the number of backfilling operations and costs. Attached Figure Description
[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the cross-section of the first-layer, one-step mining approach support of the present invention; Figure 2 This is a schematic diagram of the longitudinal section of the first-layer, one-step mining approach support of the present invention; Figure 3 This is a schematic diagram of the cross-section of the first layered two-step mining approach support of the present invention; Figure 4 This is a schematic diagram of the longitudinal section of the first layered two-step mining approach support of the present invention; Figure 5 This is a schematic diagram of the cross-section of the upper access support for the second-layer one-step mining method of the present invention; Figure 6 This is a schematic diagram of the longitudinal section of the upper access support for the second-layer one-step mining method of the present invention; Figure 7 This is a schematic diagram of the cross-section of the lower bottom support of the second-layer one-step mining method of the present invention; Figure 8 This is a schematic diagram of the longitudinal section of the lower pull-down approach support for the second layer of the one-step mining method of the present invention; Figure 9 This is a schematic diagram of the cross-section of the upper access support for the second layered two-step mining method of the present invention; Figure 10 This is a schematic diagram of the longitudinal section of the upper access support for the second layered two-step mining method of the present invention; Figure 11 This is a schematic diagram of the cross-section of the lower bottom pull-down approach support of the second layer two-step mining method of the present invention; Figure 12 This is a schematic diagram of the longitudinal section of the lower bottom support of the second layered two-step mining method of the present invention.
[0018] Figure label: 1. First stratum ore body; 2. Advance pipe roof; 3. First stratum one-step mining approach; 4. Cast-in-place piles; 5. Second stratum ore body; 6. Auxiliary support; 7. Steel arch frame; 8. Steel beam; 9. First stratum two-step mining approach; 10. Upper stratum ore body; 11. Lower stratum ore body; 12. Upper one-step mining approach in the second stratum; 13. Lower one-step mining approach in the second stratum; 14. Upper two-step mining approach in the second stratum; 15. Lower two-step mining approach in the second stratum. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0021] Reference Figures 1 to 12 As shown, this embodiment provides a safe and efficient mining and support method suitable for silty and weak ore bodies, including the following steps: S1. Preparation for the first strata of mining; including the preparation of machinery and equipment for inspection and maintenance, and materials for pipe roofs. S2, one-step mining access road support, tunneling, auxiliary support 6 and mining; advanced pipe roof 2 is arranged above the outline of the first layer one-step mining access road 3, the overlap length of the front and rear advanced pipe roof 2 is 2m, grouting, the grouting pressure is controlled at 2~3MPa; tunneling the first layer one-step mining access road 3, auxiliary support 6 is provided by anchor bolts and anchor cables, 3 rows of steel arch frames 7 are arranged at the overlap of the front and rear advanced pipe roof 2 at a spacing of 800mm, mining the ore body; S3. Install grouting piles 4 at the two sides of the first-stage mining access road to the next layer of ore body; drive perforated steel pipes into the next layer of ore body at the two sides of the first-stage mining access road; the upper diameter of the perforated steel pipes is φ20-25mm, arranged in rows of 4 holes at 500mm intervals, with the length meeting the requirement that the upper end is 1000mm away from the bottom plate of the first layer of access road, and the lower end is driven into the bottom plate of the next layer of access road; the perforated steel pipes are connected and fixed by steel beams 8; at the top of each perforated steel pipe, they are connected by steel beams 8 to enhance the integrity between the perforated steel pipes. The fixing method of steel beams 8 and perforated steel pipes depends on the site construction conditions. Grouting and reinforcement of the perforated steel pipes form grouting piles 4. The grouting pressure is controlled within 3MPa. Excessive grouting is carried out to ensure that the grout seeps out from the steel pipe holes, forming a reinforcement effect on the surrounding rock of the first-stage mining road. S4, one-step mining and backfilling; S5, Second-stage mining road support, tunneling, auxiliary support 6, mining and backfilling; pipe roofs are arranged above the outline of the first layer of the second-stage mining road 9, with the overlap length of the front and rear pipe roofs being 2m, grouting, and the grouting pressure is controlled at 2~3Mpa; tunneling of the first layer of the second-stage mining road 9, auxiliary support is provided through anchor bolts and anchor cables 6, 3 rows of steel arch frames are arranged at the overlap of the front and rear pipe roofs at a spacing of 800mm 7, mining body, and backfilling of the second-stage mining road; S6. Preparation for the second-layer mining; including the preparation of machinery and equipment for inspection and maintenance, and materials for pipe roofs; S7, Excavation of the upper access road for the first-stage mining, auxiliary support 6, mining, and backfilling; Excavation of the upper access road for the second layer of the first-stage mining 12, auxiliary support 6 through anchor bolts and anchor cables, mining the ore body, and backfilling of the upper access road for the first-stage mining; S8, one-step mining of the lower bottom pull-out approach, mining and recovery; tunneling of the second layer of one-step mining of the lower bottom pull-out approach 13, recovery of the ore body; S9. Install grouting piles 4 at the two sides of the bottom pull-in access road of the lower ore body in the first-stage mining; drive perforated steel pipes into the lower ore body at the two sides of the bottom pull-in access road of the lower ore body in the first-stage mining; the upper diameter of the perforated steel pipes is φ20-25mm, arranged in rows of 4 holes at 500mm intervals, with the length meeting the requirement that the upper end is 1000mm away from the bottom plate of the first-stage access road, and the lower end is driven into the bottom plate of the lower pull-in access road of the next layer. The perforated steel pipes are connected and fixed by steel beams 8; at the top of each perforated steel pipe, they are connected by steel beams 8 to enhance the integrity between the perforated steel pipes. The fixing method of steel beams 8 and perforated steel pipes depends on the site construction conditions. Grouting and reinforcement are carried out on the perforated steel pipes to form grouting piles 4; the grouting pressure is controlled within 3MPa, and excessive grouting is carried out to ensure that the grout seeps out from the steel pipe holes, forming a reinforcement effect on the surrounding rock of the first-stage mining; S10, One-step mining of the lower ore body access and filling; S11, Excavation of the upper access road for the second-stage mining, auxiliary support 6, mining and backfilling; Excavation of the upper access road for the second-stage mining in the second layer 14, auxiliary support 6 through anchor bolts and anchor cables, mining of the ore body, and backfilling of the upper access road for the second-stage mining; S12, the second-stage mining lower access road is excavated, mined and backfilled; the second-stage mining lower access road 15 is excavated, the ore body is mined, and the lower ore body access road of the second-stage mining is backfilled; S13. Preparation for subsequent layered mining; including the maintenance and repair of machinery and equipment, and the preparation of pipe roof materials. In subsequent layers, the operations are carried out in cycles according to the steps of S5 to S12.
[0022] Due to the weak and silty surrounding rock of the roof, the first layer has a relatively small height. The roof support for the mining approach of the first layer ore body 1 is completed through grouting support using advanced pipe roof 2, and the approach is mined in a "one-off" manner. During the excavation of the one-step mining approach, cast-in-place piles 4 are installed on both sides of the approach towards the lower ore body; simultaneously, grout seeps out from the steel pipe holes, cementing the weak and silty ore body below, ultimately forming an integrated support structure with the cast-in-place piles 4 and steel beams 8, providing a stable surrounding rock environment for the mining of the lower ore body.
[0023] During the mining of the second ore body 5 and subsequent lower ore bodies, the backfill material of the upper access road serves as the roof. Due to its superior integrity and bearing capacity compared to silty, weak rock, the access road can be supported using a lower-cost bolt and cable support method. Furthermore, because of the integrated structure formed by the cast-in-place piles 4 driven from the upper layer and the grout, starting from the second layer, each layer can be mined at a greater height, with separate upper and lower sections. For example, the upper ore body 10 and the lower ore body 11 of the second layer can be backfilled at once after mining, improving mining efficiency and reducing the number of backfilling operations and costs.
[0024] This invention can effectively manage silty and weak surrounding rock and ore body, ensure access safety, reduce the difficulty of support operations, reduce backfilling procedures, improve the efficiency of mining access construction, and effectively reduce construction costs.
[0025] Further optimization of the scheme: in steps S3 and S9, the cast-in-place pile 4 includes driving a perforated steel pipe into the next layer of ore body, connecting and fixing the perforated steel pipes with steel beams 8, and grouting and reinforcing the perforated steel pipes to form the cast-in-place pile 4.
[0026] Further optimization of the plan involves using perforated steel pipes with a diameter of 80mm to 100mm. The length of the perforated steel pipes is determined by the height of the next mining layer and needs to extend from 1m above the bottom plate of the current construction layer to the bottom plate of the next layer.
[0027] The scheme was further optimized so that the spacing between adjacent perforated steel pipes is 800mm~1000mm.
[0028] Further optimization of the scheme: the height of steel beam 8 from the bottom plate is 400mm~1000mm, the length of steel beam 8 is the same as the spacing of the perforated steel pipe, and the width of steel beam 8 is the same as the diameter of the perforated steel pipe.
[0029] The scheme was further optimized so that the diameter of the perforated steel pipe is φ20mm-25mm, with 4 perforated steel pipes arranged radially in each row and one perforated steel pipe arranged axially in each row every 500mm.
[0030] The plan was further optimized, and the support for the first and second mining approaches was changed to grouting support using the advanced pipe roof 2. The roof of the first stratum ore body 1 was reinforced by grouting support using the advanced pipe roof 2.
[0031] Further optimize the scheme. In steps S2, S5, S7 and S11, blasting is used in the excavation of the upper access road in the first step mining and the upper access road in the second step mining. The access road excavation face is the free face, and holes are drilled and explosives are loaded in the horizontal direction.
[0032] To further optimize the scheme, in steps S8 and S12, blasting is used in the excavation of the lower access road of the first-step mining and the lower access road of the second-step mining. The bottom plate of the lower access road of the first-step mining and the bottom plate of the lower access road of the second-step mining are used as free surfaces, and holes are drilled and explosives are loaded in the vertical direction.
[0033] To further optimize the scheme, the grouting pressure for the advanced pipe roof 2 is determined by the length of the pipe roof. There needs to be an overlap length of 1-2m between the advanced pipe roofs 2 in each construction section, and 2-3 steel arch frames 7 are used to provide support in the overlap section. The steel arch frames 7 are connected and fixed to the perforated steel pipes by steel beams 8.
[0034] The roof of the first stratum ore body 1 is reinforced by grouting support using advanced pipe roof 2; the support structure is further reinforced by the grouting piles 4 driven downwards in the first-step mining method of the access road, while simultaneously reinforcing the first-step and second-step mining access roads of the next stratum; the grouting piles 4 are fixed to steel beams 8, forming an integrated support structure in the second and subsequent strata, and the lower silty and weak ore body is reinforced by grout seeping through boreholes in the grouting piles 4; a greater layer height is used in the second and subsequent strata than in the first stratum. This reduces the number of filling operations in the subsequent strata access roads, simplifies the support methods for the subsequent strata access roads, increases the layer height of subsequent ore body stratification, saves economic and time costs, and improves mining efficiency.
[0035] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.
[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A safe and efficient mining and supporting method suitable for silty weak ore body, characterized in that, It comprises the following steps: S1, first sublevel mining preparation; S2, one-step mining into the roadway support, excavation, auxiliary support (6) and stoping; S3, installing cast-in-place piles (4) in the next sublevel ore body at the two sides of the one-step mining into the roadway; S4, one-step mining into the roadway filling; S5, two-step mining into the roadway support, excavation, auxiliary support (6), stoping and filling; S6, second sublevel mining preparation; S7, one-step mining into the upper roadway excavation, auxiliary support (6), stoping and filling; S8, one-step mining into the lower draw-in roadway excavation and stoping; S9, installing cast-in-place piles (4) in the next sublevel ore body at the two sides of the one-step mining into the lower draw-in roadway; S10, one-step mining into the lower draw-in roadway filling; S11, two-step mining into the upper roadway excavation, auxiliary support (6), stoping and filling; S12, two-step mining into the lower roadway excavation, stoping and filling; S13, subsequent sublevel mining preparation.
2. The safe and efficient extraction and support method suitable for silty weak ore body according to claim 1, characterized in that: The cast-in-place piles (4) in steps S3 and S9 comprise steel pipes with holes drilled into the next sublevel ore body, which are connected and fixed by steel beams (8), grouted and reinforced to form the cast-in-place piles (4).
3. The safe and efficient extraction and support method suitable for silty weak ore body according to claim 2, characterized in that: The steel pipes with holes have a diameter of 80mm-100mm, and the length is determined by the height of the next sublevel to be mined, and needs to pass through 1m above the floor of the current construction sublevel to the floor of the next sublevel.
4. The safe and efficient extraction and support method suitable for silty weak ore body according to claim 2, characterized in that: The spacing between adjacent steel pipes with holes is 800mm-1000mm.
5. The safe and efficient extraction and support method suitable for silty weak ore body according to claim 4, characterized in that: The steel beam (8) is 400mm-1000mm from the floor, the length of the steel beam (8) is the same as the spacing of the steel pipes with holes, and the width of the steel beam (8) is the same as the diameter of the steel pipes with holes.
6. The safe and efficient extraction and support method suitable for silty weak ore body according to claim 2, characterized in that: The hole diameter of the steel pipes with holes is φ20mm-25mm.
7. The safe and efficient extraction and support method suitable for silty weak ore body according to claim 1, characterized in that: The one-step mining into the roadway support and the two-step mining into the roadway support are grouted support of the advance pipe shed (2).
8. The safe and efficient extraction and support method suitable for silty weak ore body according to claim 1, characterized in that: In steps S2, S5, S7 and S11, in the one-step mining into the upper roadway and the two-step mining into the upper roadway excavation, the blasting excavation method is adopted, with the roadway excavation working face as the free surface, drilling and charging along the horizontal direction.
9. The safe and efficient extraction and support method suitable for silty weak ore body according to claim 1, characterized in that: In steps S8 and S12, in the one-step mining into the lower roadway and the two-step mining into the lower roadway excavation, the blasting excavation method is adopted, with the one-step mining into the lower roadway floor and the two-step mining into the lower roadway floor as the free surface, drilling and charging along the vertical direction.
10. The safe and efficient extraction and support method suitable for silty weak ore body according to claim 7, characterized in that: The grouting pressure of the grouting of the advance pipe shed (2) is determined by the length of the pipe shed.