A method for controlling floor heave in a mining roadway with a transverse beam and longitudinal anchor

Abstract

The application discloses a kind of beam longitudinal anchor type mining roadway floor heave control method, belong to mining roadway management technical field, comprising the following steps: S1, install U-shaped I-beam, during roadway excavation, U-shaped groove is respectively excavated in roadway floor and roadway side, after completion, U-shaped I-beam is respectively embedded in the U-shaped groove of roadway floor and roadway side portion;S2, install anchor rod, respectively install anchor rod to roadway floor and roadway side portion by anchor rod mounting hole on U-shaped steel;S3, excavate longitudinal and transverse intersecting floor groove on roadway floor;S4, use concrete to bottom-pave floor groove, form floor concrete longitudinal and transverse control bottom structure and roadway floor concrete pouring layer.The application is combined by stress release and structure reinforcement, systematically improves the stability of floor surrounding rock, to effectively inhibit the development of floor heave deformation, ensure the safety and reliability of long-term use of roadway.

Description

Technical Field

[0001] This invention belongs to the field of mining roadway management technology, and particularly relates to a method for controlling floor heave in mining roadways using a crossbeam longitudinal anchor type. Background Technology

[0002] Floor heave refers to the phenomenon of the floor rock of a tunnel bulging upwards, which is particularly noticeable in mining-affected tunnels, where the floor can bulge by tens of centimeters or even more than a meter. Firstly, the redistribution of the stress field in the surrounding rock after tunnel excavation is an external factor. When the gravity and tectonic stress of the overlying strata exceed the compressive strength of the floor rock mass, the stress will transfer to deeper layers, creating compressive stress concentration on both sides of the floor, forcing the floor rock strata to undergo plastic flow or shear slip within the tunnel space. Secondly, the properties of the floor rock strata are an internal factor. If the floor is soft rock such as mudstone or shale, or contains expansive clay minerals, it will undergo significant volume expansion under water conditions, further exacerbating floor heave. Furthermore, the infiltration of groundwater or production water not only softens the rock mass and reduces its mechanical strength, but also often combines with geological structures such as high ground stress, mining support pressure, and fault fracture zones, ultimately leading to floor instability and continuous heave.

[0003] Currently, the treatment methods for roadway floor heave include the following two approaches. (1) Reinforcement method: This method controls deformation by increasing the strength of the floor rock mass itself or increasing the support resistance. Specifically, it includes floor anchor bolts (cables), grouting reinforcement, concrete inverted arches, and closed supports. Its advantages are strong initiative, the ability to form a stable load-bearing structure, and long-lasting effects. Its disadvantages are complex construction processes (such as the difficulty of drilling anchor bolts in broken floor slabs), high costs, and the need for repeated reinforcement for severe floor heave. (2) Pressure relief method: This method creates discontinuities in the floor rock mass through methods such as excavation, loosening blasting, or dense drilling, transferring concentrated stress to deeper areas and placing the roadway floor in a stress-reduced zone, thereby releasing deformation energy. Its advantages are relatively direct construction and the ability to quickly relieve floor heave pressure. Its disadvantages are that the pressure relief effect is time-sensitive. As the surrounding rock continues to creep, the stress-reduced zone may gradually recover, and floor heave may recur, requiring regular maintenance or repeated construction.

[0004] Although existing technologies can basically meet the needs of the site, there are still problems such as complex construction and excessive heave. The key is the lack of a powerful method to change the load-bearing structure of the base plate and strengthen the support structure of the base plate, which requires further technological breakthroughs. Summary of the Invention

[0005] The purpose of this invention is to provide a method for controlling floor heave in mining roadways using a crossbeam longitudinal anchor type, in order to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a method for controlling floor heave in mining roadways using a crossbeam longitudinal anchor type, comprising the following steps: S1. Install U-shaped I-beams. During the tunnel excavation along the tunnel face, excavate U-shaped grooves in the tunnel floor and tunnel sidewalls respectively. After completion, embed the U-shaped I-beams into the U-shaped grooves in the tunnel floor and tunnel sidewalls respectively. S2. Install anchor bolts by installing anchor bolts into the tunnel floor and tunnel sidewalls through the anchor bolt installation holes on the U-shaped steel. S3. Excavate crisscrossing trenches on the floor of the tunnel. S4. Use concrete to pave the bottom of the trench, forming the longitudinal and transverse bottom control structure of the bottom concrete and the concrete pouring layer of the roadway bottom.

[0007] Optionally, the U-shaped I-beam is assembled from a base plate I-beam and side I-beams symmetrically arranged on both sides of the base plate I-beam.

[0008] Optionally, the base plate I-beam has 2-10 anchor bolt mounting holes at equal intervals, and the side I-beam has 1-5 anchor bolt mounting holes.

[0009] Optionally, in step S2, after the anchor bolt is installed, the anchor bolt is pre-tightened with a nut.

[0010] Optionally, the spacing between the U-shaped I-beams installed on the roadway floor is 700mm to 2500mm.

[0011] Optionally, the depth of the bottom plate groove is not less than the thickness of the U-shaped I-beam, and the depth of the bottom plate groove is 100mm to 700mm.

[0012] Optionally, the distance between the first bottom plate groove and the adjacent U-shaped I-beam is 100mm to 1000mm.

[0013] Optionally, the spacing between two adjacent bottom plate grooves is 200mm to 1500mm.

[0014] Optionally, the thickness of the concrete pouring layer of the tunnel floor is greater than the exposed length of the anchor bolt located on the I-beam of the floor.

[0015] Optionally, the thickness of the concrete pouring layer of the roadway floor above the roadway floor plane is 100mm to 500mm.

[0016] This invention discloses the following technical effects: During tunnel excavation, U-shaped grooves are first excavated in the tunnel floor and sidewalls, and U-shaped I-beams with pre-drilled holes are embedded in them. To further release the stress accumulated in the surrounding rock of the floor, transverse and longitudinal intersecting floor trenches are excavated in the floor area to form stress release channels. Before pouring the bottom concrete, anchor bolts are driven into the rock strata of the tunnel floor and sidewalls through the pre-drilled holes in the U-shaped steel, so that the anchor bolts form an active load-bearing structure in the floor rock strata, thereby effectively controlling the deformation of the surrounding rock. The bottom paving is then carried out, and the thickness of the bottom paving should be greater than the exposed length of the anchor bolts on the tunnel floor to prevent the anchor bolt ends from affecting the paving quality. After the concrete solidifies, the concrete will naturally form an interwoven "well"-shaped structure in the pre-excavated floor trenches, which can significantly enhance the overall deformation resistance of the floor. The above construction process follows the technical concept of "relieving pressure first and then reinforcing". By organically combining stress release and structural reinforcement, the stability of the surrounding rock of the floor is systematically improved, thereby effectively suppressing the development of floor heave deformation and ensuring the safety and reliability of the roadway for long-term use. 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 structure of the present invention; Figure 2 This is a schematic diagram of the bottom plate groove structure of the present invention; Figure 3 This is a schematic diagram of the structure at the bottom of the tunnel after the foundation is laid according to the present invention; Figure 4 This is a schematic diagram of the U-shaped I-beam structure of the present invention.

[0018] Figure label: 1. Roadway sidewall; 2. U-shaped I-beam; 3. U-shaped channel; 4. Roadway floor concrete pouring layer; 5. Floor concrete longitudinal and transverse control structure; 6. Anchor bolt; 7. Floor trench; 8. Roadway floor; 9. Nut; 10. Roadway; 11. Roadway face; 12. Anchor bolt installation hole; 13. Sidewall I-beam; 14. Floor I-beam. 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 4 As shown, this embodiment provides a method for controlling floor heave in mining roadways using a crossbeam longitudinal anchor system. This method effectively addresses the problem of roadway floor heave caused by high-stress environments during deep mining through systematic construction steps and structural design. Specifically, the method includes the following detailed steps: S1. Installation of U-shaped I-beams 2: During the excavation operation along the tunnel face 11 within tunnel 10, special steel channels for embedding U-shaped I-beams 2 must first be excavated at the tunnel floor 8 and both side walls. The dimensions of these U-shaped channels 3 should match the cross-section of the selected U-shaped I-beams 2 to ensure a stable embedding. After excavation, the pre-processed U-shaped I-beams 2 with pre-drilled anchor bolt installation holes 12 are precisely embedded into the corresponding U-shaped channels 3 in the tunnel floor 8 and tunnel side walls 1, thus providing a structural foundation for subsequent anchoring and concrete pouring.

[0022] S2. Install Anchor Bolts 6: After the U-shaped I-beam 2 is in place, use the pre-drilled anchor bolt installation holes 12 on it to drill holes into the rock strata of the tunnel floor 8 and the surrounding rock of the sidewalls, and install anchor bolts 6. After passing through the reserved holes on the U-shaped steel, the anchor bolts 6 penetrate deep into the rock mass, forming an effective anchor to the surrounding rock. After the anchor bolts 6 are installed, nuts 9 need to be installed on their exposed ends, and appropriate pre-tightening force needs to be applied to ensure that a tight mechanical connection is formed between the anchor bolts 6 and the surrounding rock, thereby constructing an active load-bearing system.

[0023] S3. Excavation of floor slab trenches 7: To further release the surrounding rock stress accumulated in the floor slab area, intersecting trenches 7 are excavated on the surface of the roadway floor slab 8 in both transverse and longitudinal directions in a grid-like pattern. These trenches not only serve as stress release channels but also provide forming space for subsequent concrete pouring, helping to form an integral structure with enhanced resistance to deformation.

[0024] S4. Concrete Base Laying Construction: After completing the trench excavation and anchor bolt 6 installation, concrete is used to lay the base of the trench 7. After the concrete fills the trench, a crisscrossing, grid-like concrete base control structure 5 will naturally form on the surface of the base, simultaneously covering the entire tunnel floor 8 area, forming a continuous and complete tunnel floor concrete pouring layer 4. This pouring layer not only serves a sealing and protective function but also, together with the anchor bolts 6 and U-shaped I-beams 2, constitutes a composite support system.

[0025] During the entire excavation and support process of tunnel 10, U-shaped trenches 3 were first excavated in the tunnel floor 8 and sidewalls, and U-shaped I-beams 2 with pre-drilled holes were embedded in them as a structural framework. To further release the high stress accumulated in the surrounding rock of the floor due to mining, horizontal and vertical trenches 7 were systematically excavated in the floor area to form multi-directional stress release channels, effectively reducing the risk of floor heave. Before laying the concrete, anchor bolts 6 were driven into the rock strata of the floor and sidewalls through the pre-drilled holes on the U-shaped I-beams 2, allowing the anchor bolts 6 to penetrate deep into the surrounding rock to form an active load-bearing structure, thereby significantly improving the overall stability and deformation resistance of the surrounding rock of the floor. Subsequently, the concrete laying operation was carried out. During construction, it was necessary to ensure that the thickness of the concrete pouring layer was greater than the exposed length of the anchor bolts 6 on the I-beams of the floor to avoid the ends of the anchor bolts 6 protruding and affecting the flatness and structural integrity of the concrete layer. After the concrete has fully solidified and hardened, it will naturally form an interwoven "well"-shaped reinforcement structure in the pre-excavated bottom slab trench 7. This structure can effectively distribute the load, suppress local deformation, and greatly improve the overall stiffness and load-bearing capacity of the bottom slab.

[0026] The above-mentioned construction process strictly follows the core design concept of "relieving pressure first and then reinforcing". By scientifically and orderly combining the stress release of the surrounding rock and the structural reinforcement measures, it achieves systematic prevention and control of the deformation of the floor heave, thereby significantly improving the long-term stability of the surrounding rock of the roadway floor 8 and ensuring the safe and reliable operation of the roadway 10 under complex geological conditions.

[0027] To further optimize this technical solution, the key components and parameters can be designed in the following detail: The U-shaped I-beam 2 is assembled from the bottom plate I-beam 14 located in the center of the roadway floor 8 and the side plate I-beams 13 symmetrically arranged on both sides, forming a U-shaped support frame with coordinated overall force; 2 to 10 anchor bolt installation holes 12 are evenly spaced along the length of the bottom plate I-beam 14 to evenly distribute the bottom plate anchor points, while 1 to 5 anchor bolt installation holes 12 are correspondingly set on each side plate I-beam 13 to meet the side plate support requirements.

[0028] In step S2, after the anchor bolt 6 is installed, the matching nut 9 must be installed in a timely manner and a pre-tightening force must be applied to ensure the effectiveness and reliability of the anchoring system. The installation spacing of the U-shaped I-beam 2 on the roadway floor 8 is controlled between 700mm and 2500mm to balance support density and construction efficiency. The excavation depth of the floor trench 7 is not less than the flange thickness of the U-shaped I-beam 2, usually set to 100mm to 700mm, to ensure a good bond between the concrete layer and the steel components.

[0029] The distance between the first bottom plate trench 7 and the edge of the adjacent U-shaped I-beam 2 should be controlled within the range of 100mm to 1000mm to avoid stress concentration; the center distance between two adjacent bottom plate trenches 7 should be set between 200mm and 1500mm to ensure the reasonable distribution and mechanical efficiency of the "well" structure; in addition, the final thickness of the concrete pouring layer 4 of the roadway bottom plate must be greater than the exposed length of the anchor rod 6 on the bottom plate I-beam to prevent the exposed ends of the anchor rod 6 from affecting the paving quality and flatness; considering engineering practice and structural requirements, the recommended thickness of the concrete pouring layer 4 of the roadway bottom plate is 100mm to 500mm, which can meet the structural strength requirements and has good construction operability.

[0030] 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.

[0031] 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 method for controlling floor heave in a mining roadway using a crossbeam longitudinal anchor system, characterized in that, Includes the following steps: S1. Install U-shaped I-beams (2). During the excavation along the tunnel face (11) in the tunnel (10), excavate U-shaped grooves (3) in the tunnel floor (8) and tunnel side (1) respectively. After completion, embed the U-shaped I-beams (2) into the U-shaped grooves (3) in the tunnel floor (8) and tunnel side (1) respectively. S2. Install anchor bolts (6). Install anchor bolts (6) into the roadway floor (8) and roadway sidewall (1) respectively through the anchor bolt installation holes (12) on the U-shaped steel. S3. Excavate crisscrossing trenches (7) on the bottom slab (8) of the tunnel. S4. Use concrete to pave the bottom of the trench (7) to form the bottom concrete longitudinal and transverse control structure (5) and the roadway bottom concrete pouring layer (4).

2. The method for controlling floor heave in mining roadways using a crossbeam longitudinal anchorage system according to claim 1, characterized in that: The U-shaped I-beam (2) is assembled from a base plate I-beam (14) and side I-beams (13) symmetrically arranged on both sides of the base plate I-beam (14).

3. The method for controlling floor heave in mining roadways using a crossbeam longitudinal anchorage as described in claim 2, characterized in that: The bottom plate I-beam (14) is provided with 2-10 anchor bolt mounting holes (12) at equal intervals, and the side I-beam (13) is provided with 1-5 anchor bolt mounting holes (12).

4. The method for controlling floor heave in mining roadways using a crossbeam longitudinal anchorage system according to claim 1, characterized in that: In step S2, after the anchor rod (6) is installed, the nut (9) is used to pre-tighten the anchor rod (6).

5. The method for controlling floor heave in mining roadways using a crossbeam longitudinal anchorage system according to claim 1, characterized in that: The spacing between the U-shaped I-beams (2) installed on the roadway floor plate (8) is 700mm to 2500mm.

6. The method for controlling floor heave in mining roadways using a crossbeam longitudinal anchorage system according to claim 1, characterized in that: The depth of the bottom plate groove (7) is not less than the thickness of the U-shaped I-beam (2), and the depth of the bottom plate groove (7) is 100mm to 700mm.

7. The method for controlling floor heave in mining roadways using a crossbeam longitudinal anchorage system according to claim 1, characterized in that: The distance between the first bottom plate groove (7) and the adjacent U-shaped I-beam (2) is 100mm to 1000mm.

8. The method for controlling floor heave in mining roadways using a crossbeam longitudinal anchorage system according to claim 1, characterized in that: The distance between two adjacent bottom plate grooves (7) is 200mm to 1500mm.

9. The method for controlling floor heave in mining roadways using a crossbeam longitudinal anchorage system according to claim 2, characterized in that: The thickness of the concrete pouring layer (4) of the roadway floor is greater than the exposed length of the anchor bolt (6) located on the I-beam (14) of the floor.

10. The method for controlling floor heave in a mining roadway using a crossbeam longitudinal anchorage as described in claim 1, characterized in that: The thickness of the concrete pouring layer (4) above the plane of the roadway floor slab (8) is 100mm to 500mm.

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