Soft rock roadway bottom plate reinforcing method

Abstract

The invention provides a soft rock roadway bottom plate reinforcing method. The soft rock roadway bottom plate reinforcing method comprises the following steps that S1, a bottom plate of a roadway is trimmed; s2, a reinforcing mesh is laid on the first concrete layer; anchor rods and / or anchor cables are driven to the bottom plate at intervals on the first net layer in the extending direction of the roadway; s3, grouting is conducted in the holes where the anchor rods and / or the anchor cables are located so that anchoring and fixing can be achieved; then, grouting is conducted on the first net layer; s4, a reinforcing mesh is laid on the second concrete layer, then grouting is conducted on the second mesh layer, a third concrete layer is formed through solidification, and the part, facing the second mesh layer, of the third concrete layer is of a downwards-protruding arch structure; by means of the method, the bottom plate of the roadway is stabilized and reinforced, the supporting and reinforcing strength of the bottom plate is higher, the three concrete layers have certain elastic deformation capacity, damage, cracks and failure caused by damage to the surface of the bottom plate of the roadway are avoided, and long-term stable work of the roadway is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel floor reinforcement, and in particular to a soft rock tunnel floor reinforcement method. Background Art

[0002] At present, soft rock geological conditions have a great impact on coal mining. In tunnels such as shafts, connecting tunnels, and production tunnels, soft rock floors are usually deformed due to insufficient strength. In order to reinforce soft rock tunnels, the existing technology usually adopts the method of installing anchor rods on the floor and pouring concrete to support and reinforce the floor. However, although the above method can enhance the strength of the floor, due to the poor elastic deformation capacity of concrete, when the ground stress fluctuates or the mine pressure is obvious, the above floor reinforcement method cannot effectively resist the deformation of the tunnel floor, and then the concrete layer on the surface of the tunnel floor is damaged and cracked. Under long-term action, the floor will be destroyed, seriously affecting the normal use of the tunnel, and seriously affecting the efficiency and safety of material transportation, tunnel ventilation, personnel walking and coal mine safety production. At the same time, the above method requires multiple pouring and reinforcement maintenance of the floor every time the floor is damaged. The repeated maintenance requires a large amount of engineering investment, consumes a lot of manpower and material resources, and has a high cost. Summary of the invention

[0003] The present invention provides a soft rock tunnel floor reinforcement method to solve the problem that the floor reinforcement method of the prior art combining anchor rod driving and concrete pouring cannot effectively resist the deformation of the tunnel floor, requires multiple maintenance, reduces production efficiency and increases maintenance costs.

[0004] In order to solve the above problems, the present invention provides a method for reinforcing the bottom plate of a soft rock tunnel, comprising the following steps: S1, trimming the bottom plate of the tunnel so that the bottom plate becomes a downwardly protruding arch structure, laying a plurality of grouting pipes for grouting on the bottom plate, and then performing grouting so that the concrete material used for grouting covers the bottom plate and solidifies to form a first concrete layer, the first concrete layer being a downwardly protruding arch structure; S2, laying a steel mesh on the first concrete layer so that the steel mesh covers the upper surface of the first concrete layer to form a first mesh layer, after the laying is completed, laying a W-shaped steel belt and a circular steel belt on the first mesh layer, the W-shaped steel belt and the circular steel belt are respectively connected to the first mesh layer to reinforce the first mesh layer; anchor rods and / or anchor cables are driven into the bottom plate at intervals along the extension direction of the tunnel on the first mesh layer, so that the anchor rods and / or anchor cables reinforce the bottom plate and the first concrete layer. Soil layer and the first mesh layer; S3, grouting into the holes where the anchor rods and / or anchor cables are located to achieve anchoring and fixation; then grouting is performed above the first mesh layer, so that the concrete material used for grouting covers the first mesh layer, W-shaped steel belt and circular steel belt, and solidifies to form a second concrete layer, and the second concrete layer is a downwardly protruding arch structure; S4, laying a steel mesh on the second concrete layer, so that the steel mesh covers the upper surface of the second concrete layer to form a second mesh layer. After the laying is completed, the steel mesh in the second mesh layer is fixed on the second concrete layer, and then grouting is performed above the second mesh layer, so that the concrete material used for grouting covers the second mesh layer, and solidifies to form a third concrete layer, and the part of the third concrete layer facing the second mesh layer is a downwardly protruding arch structure; the surface of the third concrete layer facing upward is leveled for passage in the tunnel.

[0005] Furthermore, in step S1, before grouting, the bottom of the tunnel walls on both sides of the tunnel are excavated so that the bottom space of the tunnel walls can expand to both sides respectively; during grouting, the concrete material is controlled to fill the bottom space of the tunnel walls so that the width of the first concrete layer in the horizontal direction is greater than the width of the tunnel in the horizontal direction; the thickness of the first concrete layer is not less than 150 mm.

[0006] Furthermore, in step S2, at the bottom of the tunnel wall, anchor rods and / or anchor cables are driven to both sides of the tunnel wall, and the anchor rods and / or anchor cables are controlled to be connected to at least one of the first mesh layer, the W-shaped steel belt and the circular steel belt to reinforce the bottom of the tunnel wall.

[0007] Furthermore, in step S2, a plurality of anchor beams are fixedly installed at the bottom of the lane wall, and the extension direction of the anchor beams is parallel to the extension direction of the lane; the plurality of anchor beams are arranged at intervals along the extension direction of the lane; when anchor rods and / or anchor cables are driven into both sides of the lane wall, at least a portion of the plurality of anchor rods and / or anchor cables are connected to the anchor beams to anchor and fix the anchor beams and the bottom of the lane wall.

[0008] Furthermore, in step S1, at least a portion of the multiple grouting pipes are arranged to extend downward into the bottom plate, so that the concrete material fills the delamination cracks below the bottom plate to improve the strength of the stratum below the bottom plate.

[0009] Furthermore, in step S2, when driving anchor rods and / or anchor cables, the lengths of the multiple anchor rods and / or multiple anchor cables used are different or the same; the inner diameter of the hole where the anchor rods and / or anchor cables are located changes along its extension direction, so that the fitting relationship between the anchor rods and / or anchor cables and the inner wall of the hole changes along its extension direction, and the fitting relationship includes interference fit, transition fit and clearance fit.

[0010] Further, in step S2, the extension direction of the W-shaped steel belt is set parallel to the extension direction of the tunnel, and multiple W-shaped steel belts are arranged in parallel and spaced apart; the extension direction of the circular steel belt is set perpendicular to the extension direction of the tunnel, and multiple circular steel belts are arranged in parallel and spaced apart; at least a portion of the circular steel belt is cross-arranged with at least a portion of the W-shaped steel belt, and anchor rods and / or anchor cables are installed at the intersection of a circular steel belt and a W-shaped steel belt, so that the steel mesh, the circular steel belt, and the W-shaped steel belt are respectively tensioned into one with the anchor rods and / or anchor cables.

[0011] Furthermore, the thickness of the first concrete layer is not greater than the thickness of the second concrete layer, and the thickness of the second concrete layer is not greater than the thickness of the third concrete layer.

[0012] Further, in step S2, driving the anchor cable or anchor rod includes the following steps: drilling a casing hole on the first concrete layer, and then drilling an anchor hole downward in the casing hole, the hole diameter of the anchor hole is smaller than the casing hole, and installing the anchor cable or anchor rod and resin roll inside the anchor hole, so that the resin roll fixes the anchor cable or anchor rod, and then installing a fixed casing outside the anchor cable or anchor rod, and making at least a part of the fixed casing cooperate with the inner wall of the casing hole; then installing a grouting plug for grouting at the outlet of the casing hole, controlling the concrete material to pass through the grouting plug into the casing hole and the anchor hole for grouting and solidification, so as to fix the anchor cable or anchor rod in the formation.

[0013] Furthermore, in step S2, after the concrete material solidifies in the casing hole and the anchor hole, a pallet is installed on one end of the anchor cable or anchor rod located on the first mesh layer, so that the pallet is located above the W-shaped steel belt and the round steel belt, and is connected to the anchor cable or anchor rod; then a spherical pad and a lock are sequentially mounted on one end of the anchor cable or anchor rod located on the first mesh layer, so that the two ends of the spherical pad are respectively abutted against the lock and the pallet, and the lock locks the spherical pad and the pallet on the anchor cable or anchor rod, and the anchor cable or anchor rod presses the steel mesh, the round steel belt, and the W-shaped steel belt onto the first concrete layer.

[0014] Applying the technical solution of the present invention, the present invention proposes a method for reinforcing the bottom plate of a soft rock tunnel, comprising the following steps: S1, trimming the bottom plate of the tunnel so that the bottom plate becomes a downwardly protruding arch structure, laying a plurality of grouting pipes for grouting on the bottom plate, and then performing grouting so that the concrete material used for grouting covers the bottom plate and solidifies to form a first concrete layer, wherein the first concrete layer is a downwardly protruding arch structure; S2, laying a steel mesh on the first concrete layer so that the steel mesh covers the upper surface of the first concrete layer to form a first mesh layer, and after the laying is completed, laying a W-shaped steel belt and a circular steel belt on the first mesh layer, the W-shaped steel belt and the circular steel belt are respectively connected to the first mesh layer to reinforce the first mesh layer; on the first mesh layer, anchor rods and / or anchor cables are driven into the bottom plate at intervals along the extension direction of the tunnel, so that the anchor rods and / or anchor cables reinforce the bottom plate and the first concrete layer. Soil layer and the first mesh layer; S3, grouting into the holes where the anchor rods and / or anchor cables are located to achieve anchoring and fixation; then grouting is performed above the first mesh layer, so that the concrete material used for grouting covers the first mesh layer, W-shaped steel belt and circular steel belt, and solidifies to form a second concrete layer, and the second concrete layer is a downwardly protruding arch structure; S4, laying a steel mesh on the second concrete layer, so that the steel mesh covers the upper surface of the second concrete layer to form a second mesh layer. After the laying is completed, the steel mesh in the second mesh layer is fixed on the second concrete layer, and then grouting is performed above the second mesh layer, so that the concrete material used for grouting covers the second mesh layer, and solidifies to form a third concrete layer, and the part of the third concrete layer facing the second mesh layer is a downwardly protruding arch structure; the surface of the third concrete layer facing upward is leveled for passage in the tunnel.

[0015] The method of the present invention realizes stable reinforcement of the bottom plate of the tunnel by arranging the first concrete layer, the first mesh layer, the second concrete layer, the second mesh layer and the third concrete layer in sequence, and then combining the design of the arch mechanical structure and adopting W-shaped steel belts, round steels, anchor rods and / or anchor cables, especially suitable for the reinforcement of the bottom plate of soft rock tunnels; compared with the method of the prior art that adopts the method of setting anchor rods on the bottom plate and combining with pouring concrete, the method of the present invention not only has stronger support and reinforcement strength for the bottom plate, but also because the design of the first mesh layer, the second mesh layer, the W-shaped steel belt and the round steel makes the three concrete layers have a certain elastic deformation capacity, when the ground stress fluctuates or the mine pressure becomes obvious, the composite bottom plate reinforcement structure formed by the method of the present invention can effectively resist the deformation of the bottom plate, avoid the damage, cracks and destruction failure of the bottom plate surface of the tunnel, ensure the long-term stable operation of the tunnel, and avoid the influence of ground stress fluctuation on the transportation of materials and the tunnel The method of reinforcing the bottom plate of the soft rock tunnel provided by the present application can significantly enhance the stability of the bottom plate of the soft rock tunnel, effectively control the deformation of the bottom plate, and prevent the occurrence of the bottom drum phenomenon of the tunnel; the bottom plate arch finishing and grouting reinforcement method are adopted to improve the integrity and adhesion of the rock layer below the bottom plate, thereby improving the overall bearing capacity of the rock layer below the bottom plate; the structural strength and deformation resistance of the bottom plate are further enhanced by combining the concrete layer and the deep anchoring; although the initial capital investment of the method of the present invention is relatively high, in the long run, it reduces the high cost of multiple maintenance; the implementation steps of the method of the present invention are simple, which is convenient for overall implementation in the tunnel and suitable for large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A flowchart showing some method steps provided by an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of a part of the structure in a lane in a front view provided by an embodiment of the present invention is shown;

[0019] Figure 3 A schematic diagram showing the coordination of various structures arranged on a steel bar mesh provided by an embodiment of the present invention from a top view is shown;

[0020] Figure 4A schematic diagram of the internal structure of an embodiment of the present invention when an anchor cable is installed at a frontal angle is shown.

[0021] The above drawings include the following reference numerals:

[0022] 10. Bottom plate; 11. Lane side; 12. Delamination cracks;

[0023] 20. Grouting pipe;

[0024] 30. First concrete layer;

[0025] 40. Steel mesh; 41. W-shaped steel belt; 42. Round steel belt; 43. Anchor cable; 44. Anchor beam;

[0026] 50. The first network layer;

[0027] 60. Second concrete layer;

[0028] 70. Second network layer;

[0029] 80. The third concrete layer;

[0030] 90. Casing hole; 91. Anchor hole; 92. Resin roll; 93. Fixed casing; 94. Stop plug; 95. Tray; 96. Spherical pad; 97. Lock. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] like Figures 1 to 4As shown, an embodiment of the present invention provides a method for reinforcing the bottom plate of a soft rock tunnel, comprising the following steps: S1, trimming the bottom plate 10 of the tunnel so that the bottom plate 10 becomes a downwardly protruding arch structure, arranging a plurality of grouting pipes 20 for grouting on the bottom plate 10, and then performing grouting so that the concrete material for grouting covers the bottom plate 10 and solidifies to form a first concrete layer 30, the first concrete layer 30 being a downwardly protruding arch structure; S2, The steel mesh 40 is laid on the surface of the first concrete layer 30 so that the steel mesh 40 covers the upper surface of the first concrete layer 30 to form a first mesh layer 50. After the laying is completed, a W-shaped steel belt 41 and a round steel belt 42 are laid on the first mesh layer 50, and the W-shaped steel belt 41 and the round steel belt 42 are respectively connected to the first mesh layer 50 to reinforce the first mesh layer 50; anchor rods and / or anchor cables 43 are driven toward the bottom plate 10 at intervals along the extension direction of the roadway on the first mesh layer 50, so that the anchor rods and / or anchor cables 43 reinforce the bottom plate 10 and the first concrete layer 30. Soil layer 30 and first mesh layer 50; S3, grouting into the holes where the anchor rods and / or anchor cables 43 are located to achieve anchoring and fixing; then grouting is performed above the first mesh layer 50, so that the concrete material used for grouting covers the first mesh layer 50, the W-shaped steel belt 41 and the circular steel belt 42, and solidifies to form a second concrete layer 60, and the second concrete layer 60 is a downwardly protruding arch structure; S4, laying the steel mesh 40 on the second concrete layer 60, so that the steel mesh 40 covers the upper surface of the second concrete layer 60 to form a second mesh layer 70, after the laying is completed, the steel mesh 40 in the second mesh layer 70 is fixed on the second concrete layer 60, and then grouting is performed above the second mesh layer 70, so that the concrete material used for grouting covers the second mesh layer 70, and solidifies to form a third concrete layer 80, and the portion of the third concrete layer 80 facing the second mesh layer 70 is a downwardly protruding arch structure; the surface of the third concrete layer 80 facing upward is leveled for passage in the tunnel.

[0033] By setting the first concrete layer 30, the first mesh layer 50, the second concrete layer 60, the second mesh layer 70 and the third concrete layer 80 in sequence, and then combining the arch mechanical structure design and using W-shaped steel belts 41, round steel, anchor rods and / or anchor cables 43, a stable reinforcement of the bottom plate 10 of the tunnel is achieved, especially suitable for the reinforcement of the bottom plate 10 of the soft rock tunnel; compared with the method of the prior art that uses anchor rods on the bottom plate 10 and combines it with pouring concrete, the method of the present invention not only has a stronger support and reinforcement strength for the bottom plate 10, but also because the design of the first mesh layer 50, the second mesh layer 70, the W-shaped steel belt 41 and the round steel makes the three layers of concrete have a certain elastic deformation capacity. When the ground stress fluctuates or the mine pressure becomes obvious, the composite bottom plate 10 reinforcement structure formed by the method of the present invention can effectively resist the deformation of the bottom plate 10, avoid damage, cracks and failure on the surface of the bottom plate 10 of the tunnel, ensure the long-term stable operation of the tunnel, and avoid the ground stress fluctuation on the tunnel. The method of reinforcing the bottom plate of the soft rock tunnel provided by the present application can significantly enhance the stability of the bottom plate 10 of the soft rock tunnel, effectively control the deformation of the bottom plate 10, and prevent the occurrence of the bottom drum phenomenon of the tunnel; the arch trimming and grouting reinforcement method of the bottom plate 10 is adopted to improve the integrity and adhesion of the rock layer below the bottom plate 10, thereby improving the overall bearing capacity of the rock layer below the bottom plate 10; the structural strength and deformation resistance of the bottom plate 10 are further enhanced by combining the concrete layer and the deep anchoring; although the initial capital investment of the method of the present invention is relatively high, in the long run, it reduces the high cost of multiple maintenance; the implementation steps of the method of the present invention are simple, which is convenient for overall implementation in the tunnel and suitable for large-scale promotion and use.

[0034] like Figure 2 As shown, in step S1, before grouting, the bottom of the tunnel side 11 on both sides of the tunnel is excavated so that the bottom space of the tunnel side 11 can expand to both sides respectively; during grouting, the concrete material is controlled to fill the bottom space of the tunnel side 11 so that the width of the first concrete layer 30 in the horizontal direction is greater than the width of the tunnel in the horizontal direction; the thickness of the first concrete layer 30 is not less than 150 mm.

[0035] By excavating at the bottom of the tunnel wall and controlling the filling of concrete materials, the horizontal width of the first concrete layer exceeds the width of the tunnel and the thickness is not less than 150mm. This not only increases the supporting force of the tunnel floor on the side walls and prevents the floor from moving laterally, but also increases the thickness of the floor, improving its bearing capacity, which helps to more effectively resist the deformation stress of the tunnel floor.

[0036] like Figure 2As shown, in step S2, at the bottom of the lane wall 11, anchor rods and / or anchor cables 43 are driven to both sides of the lane wall 11 respectively, and the anchor rods and / or anchor cables 43 are controlled to be connected to at least one of the first mesh layer 50, the W-shaped steel belt 41 and the circular steel belt 42 to reinforce the bottom of the lane wall 11.

[0037] By arranging anchor rods and / or anchor cables 43 at the bottom of the tunnel wall, the tunnel wall 11 can be connected to the first mesh layer, the W-shaped steel belt 41 and the circular steel belt 42, thereby further reinforcing the bottom of the tunnel wall 11; at the same time, the connection strength between the tunnel wall 11 and the bottom plate 10 is also increased, ensuring that the tunnel wall 11 is not easily displaced under the action of mine pressure, thereby improving the stability and safety of the overall structure of the tunnel.

[0038] like Figure 2 and Figure 3 As shown, in step S2, a plurality of anchor beams 44 are fixedly installed at the bottom of the lane wall 11, and the extension direction of the anchor beams 44 is parallel to the extension direction of the lane; the plurality of anchor beams 44 are arranged at intervals along the extension direction of the lane; when anchor rods and / or anchor cables 43 are driven into both sides of the lane wall 11, at least a portion of the plurality of anchor rods and / or anchor cables 43 are connected to the anchor beams 44 to anchor and fix the anchor beams 44 and the bottom of the lane wall 11.

[0039] By fixing multiple anchoring beams 44 parallel to the tunnel at the bottom of the tunnel wall, and connecting some anchor rods and / or anchor cables thereto, the bottom of the tunnel wall 11 is anchored and fixed to the bottom plate 10; the use of the anchoring beams 44 can disperse the stress of the tunnel bottom plate 10 and the tunnel wall 11, prevent local damage caused by stress concentration, and ensure the structural integrity of the bottom plate 10 and the tunnel wall 11.

[0040] like Figure 2 As shown, in step S1 , at least a portion of the multiple grouting pipes 20 are extended into the bottom plate 10 and downward, so that the concrete material fills the delamination cracks 12 below the bottom plate 10 to improve the strength of the stratum below the bottom plate 10 .

[0041] By partially extending the grouting pipe 20 under the bottom plate 10, it is ensured that the concrete material can fill the delamination cracks 12 under the bottom plate 10, thereby improving the strength of the lower strata, compensating for the structural defects of the rock layer under the bottom plate 10, enhancing the adhesion between the bottom plate 10 and the lower rock layer, preventing vertical settlement of the bottom plate, and improving the bearing capacity of the tunnel bottom plate 10.

[0042] like Figure 2 As shown, in step S2, when driving anchor rods and / or anchor cables 43, the lengths of the multiple anchor rods and / or multiple anchor cables 43 used are different or the same; the inner diameter of the hole where the anchor rods and / or anchor cables 43 are located changes along its extension direction, so that the matching relationship between the anchor rods and / or anchor cables 43 and the inner wall of the hole changes along its extension direction, and the matching relationship includes interference fit, transition fit and clearance fit.

[0043] By using anchor rods and / or anchor cables 43 of different lengths, as well as changes in the inner diameter of the hole along the extension direction, it is possible to adapt to the deformation of different parts of the base plate 10 and achieve a more precise anchoring effect; this design can ensure the effective anchoring of the anchor cables 43 or anchor rods at various parts of the base plate 10, thereby improving the adaptability and reliability of the support structure.

[0044] like Figure 2 and Figure 3 As shown, in step S2, the extension direction of the W-shaped steel belt 41 is set to be parallel to the extension direction of the tunnel, and multiple W-shaped steel belts 41 are set in parallel and spaced apart; the extension direction of the circular steel belt 42 is set to be perpendicular to the extension direction of the tunnel, and multiple circular steel belts 42 are set in parallel and spaced apart; at least a portion of the circular steel belt 42 is cross-arranged with at least a portion of the W-shaped steel belt 41, and anchor rods and / or anchor cables 43 are installed at the intersection of a circular steel belt 42 and a W-shaped steel belt 41, so that the steel mesh 40, the circular steel belt 42, and the W-shaped steel belt 41 are respectively tensioned into one with the anchor rods and / or anchor cables 43.

[0045] By cross-setting the W-shaped steel belt 41 and the circular steel belt 42 and using them in combination with anchor rods and / or anchor cables 43, a grid-like support structure can be formed to increase the tensile strength and overall rigidity of the base plate; this structure can more effectively disperse stress, prevent local damage to the base plate of the soft rock tunnel, and at the same time improve the stability of the entire base plate.

[0046] like Figure 2 As shown, the thickness of the first concrete layer 30 is not greater than the thickness of the second concrete layer 60 , and the thickness of the second concrete layer 60 is not greater than the thickness of the third concrete layer 80 .

[0047] By increasing the thickness of each layer of concrete successively, the bearing capacity and deformation resistance of the bottom plate can be gradually improved; this design can adapt to the stress changes of the tunnel bottom plate with increasing depth, ensuring that the support structure can maintain good stability in rock strata at different depths.

[0048] like Figure 3 and Figure 4As shown, in step S2, driving the anchor cable 43 or the anchor rod includes the following steps: drilling a casing hole 90 on the first concrete layer 30, and then drilling an anchor hole 91 downward in the casing hole 90, wherein the aperture of the anchor hole 91 is smaller than that of the casing hole 90, and installing the anchor cable 43 or the anchor rod and the resin roll 92 inside the anchor hole 91, so that the resin roll 92 fixes the anchor cable 43 or the anchor rod, and then installing a fixed sleeve 93 outside the anchor cable 43 or the anchor rod, and making at least a portion of the fixed sleeve 93 limitedly cooperate with the inner wall of the casing hole 90; and then installing a grouting stopper 94 for grouting at the outlet of the casing hole 90, and controlling the concrete material to pass through the grouting stopper 94 into the casing hole 90 and the anchor hole 91 for grouting and solidification, so as to fix the anchor cable 43 or the anchor rod in the formation.

[0049] By drilling casing holes 90 and anchor holes 91 on the first concrete layer, installing resin-coated fixed anchor cables 43 or anchor rods, and installing fixed casings 93 and grouting plugs on the outside for grouting, deep anchoring and effective sealing of the anchor cables 43 or anchor rods can be achieved to prevent slurry leakage and ensure the anchoring effect; at the same time, this installation method can significantly improve the firmness of the anchoring structure, reduce subsequent maintenance work, and reduce safety hazards.

[0050] like Figure 3 and Figure 4 As shown, in step S2, after the concrete material solidifies in the casing hole 90 and the anchor hole 91, a tray 95 is installed on one end of the anchor cable 43 or the anchor rod located on the first mesh layer 50, so that the tray 95 is located above the W-shaped steel belt 41 and the round steel belt 42, and is connected to the anchor cable 43 or the anchor rod; then, a spherical pad 96 and a lock 97 are sequentially mounted on one end of the anchor cable 43 or the anchor rod located on the first mesh layer 50, so that the two ends of the spherical pad 96 are respectively abutted against the lock 97 and the tray 95, and the lock 97 locks the spherical pad 96 and the tray 95 on the anchor cable 43 or the anchor rod, and the anchor cable 43 or the anchor rod presses the steel mesh 40, the round steel belt 42, and the W-shaped steel belt 41 onto the first concrete layer 30.

[0051] Installing a tray 95, a spherical pad 96 and a lock 97 on the top of the anchor cable 43 or the anchor rod can ensure that the steel mesh 40, the W-shaped steel belt 41 and the round steel belt 42 are pressed against the concrete layer, and at the same time, these components are locked to the anchor cable 43 or the anchor rod through the lock 97 to form an integral support structure; this design can improve the compactness of the bottom plate support structure, further enhance its bearing capacity and ability to resist deformation, and ensure that the tunnel bottom plate remains stable for a long time.

[0052] In summary, the present invention provides a method for reinforcing the bottom plate of a soft rock tunnel, which is formed in sequence by setting a first concrete layer 30, a first mesh layer 50, a second concrete layer 60, a second mesh layer 70 and a third concrete layer 80, and then combining the arch mechanical structure design and using W-shaped steel belts 41, round steel, anchor rods and / or anchor cables 43 to achieve a stable reinforcement of the bottom plate 10 of the tunnel, especially suitable for reinforcing the bottom plate 10 of the soft rock tunnel; compared with the method of the prior art that uses anchor rods on the bottom plate 10 and combines it with pouring concrete, the method of the present invention not only has a stronger support and reinforcement strength for the bottom plate 10, but also because the design of the first mesh layer 50, the second mesh layer 70, the W-shaped steel belt 41 and the round steel makes the three layers of concrete have a certain elastic deformation capacity. When the ground stress fluctuates or the mine pressure is obvious, the composite bottom plate 10 reinforcement structure formed by the method of the present invention can effectively resist the deformation of the bottom plate 10, avoid damage, cracks and failure on the surface of the bottom plate 10 of the tunnel, and ensure the long-term stable operation of the tunnel. , avoiding the adverse effects of ground stress fluctuations on the efficiency and safety of material transportation, tunnel ventilation, personnel walking and coal mine production safety in the tunnel; at the same time, the method of the present invention does not need to cast and reinforce the bottom plate 10 for many times, nor does it need repeated maintenance, which effectively reduces the amount of engineering and capital investment, saves manpower and material resources, and reduces costs; the soft rock tunnel bottom plate reinforcement method provided by the present application can significantly enhance the stability of the bottom plate 10 of the soft rock tunnel, effectively control the deformation of the bottom plate 10, and prevent the occurrence of tunnel bottom drum phenomenon; the arch trimming and grouting reinforcement method of the bottom plate 10 is adopted to improve the integrity and adhesion of the rock layer below the bottom plate 10, thereby improving the overall bearing capacity of the rock layer below the bottom plate 10; the structural strength and deformation resistance of the bottom plate 10 are further enhanced by combining the concrete layer and deep anchoring; although the initial capital investment of the method of the present invention is relatively high, in the long run, it reduces the high cost of multiple maintenance; the implementation steps of the method of the present invention are simple, which is convenient for overall implementation in the tunnel and is suitable for large-scale promotion and use.

[0053] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0054] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0055] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0056] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0057] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for reinforcing the bottom plate of a soft rock tunnel, characterized in that: The steps include: S1, trimming the bottom plate (10) of the tunnel so that the bottom plate (10) becomes a downwardly protruding arch structure, arranging a plurality of grouting pipes (20) for grouting on the bottom plate (10), and then performing grouting so that the concrete material for grouting covers the bottom plate (10) and solidifies to form a first concrete layer (30), wherein the first concrete layer (30) is a downwardly protruding arch structure; S2, laying a steel mesh (40) on the first concrete layer (30) so that the steel mesh (40) covers the upper surface of the first concrete layer (30) to form a first mesh layer (50); after the laying is completed, laying a W-shaped steel belt (41) and a round steel belt (42) on the first mesh layer (50), wherein the W-shaped steel belt (41) and the round steel belt (42) are respectively connected to the first mesh layer (50) to reinforce the first mesh layer (50); anchor rods and / or anchor cables (43) are driven at intervals along the extension direction of the tunnel toward the bottom plate (10) on the first mesh layer (50), so that the anchor rods and / or the anchor cables (43) reinforce the bottom plate (10), the first concrete layer (30) and the first mesh layer (50); S3, injecting grout into the hole where the anchor rod and / or the anchor cable (43) is located to achieve anchoring and fixing; then injecting grout above the first mesh layer (50), so that the concrete material used for grouting covers the first mesh layer (50), the W-shaped steel belt (41) and the circular steel belt (42), and solidifies to form a second concrete layer (60), wherein the second concrete layer (60) is a downwardly protruding arch structure; S4. Laying a steel mesh (40) on the second concrete layer (60) so that the steel mesh (40) covers the upper surface of the second concrete layer (60) to form a second mesh layer (70). After the laying is completed, the steel mesh (40) in the second mesh layer (70) is fixed on the second concrete layer (60). Then, grouting is performed on the second mesh layer (70) so that the concrete material used for grouting covers the second mesh layer (70) and solidifies to form a third concrete layer (80). The portion of the third concrete layer (80) facing the second mesh layer (70) is a downwardly protruding arch structure. The surface of the third concrete layer (80) facing upward is leveled for passage in the tunnel.

2. The soft rock tunnel floor reinforcement method according to claim 1 is characterized in that: In the step S1, before grouting, the bottom of the tunnel walls (11) on both sides of the tunnel are excavated so that the bottom space of the tunnel walls (11) expands to both sides respectively; during grouting, the concrete material is controlled to fill the bottom space of the tunnel walls (11) so that the width of the first concrete layer (30) in the horizontal direction is greater than the width of the tunnel in the horizontal direction; the thickness of the first concrete layer (30) is not less than 150 mm.

3. The soft rock tunnel floor reinforcement method according to claim 2 is characterized in that: In the step S2, anchor rods and / or anchor cables (43) are driven into the bottom of the lane wall (11) on both sides of the lane wall (11), and the anchor rods and / or anchor cables (43) are controlled to be connected to at least one of the first mesh layer (50), the W-shaped steel belt (41) and the circular steel belt (42) to reinforce the bottom of the lane wall (11).

4. The soft rock tunnel floor reinforcement method according to claim 3 is characterized in that: In step S2, a plurality of anchor beams (44) are fixedly installed at the bottom of the lane wall (11), and the extension direction of the anchor beams (44) is parallel to the extension direction of the lane; the plurality of anchor beams (44) are arranged at intervals along the extension direction of the lane; when anchor rods and / or anchor cables (43) are driven on both sides of the lane wall (11), at least a portion of the plurality of anchor rods and / or anchor cables (43) are connected to the anchor beams (44) to anchor and fix the anchor beams (44) and the bottom of the lane wall (11).

5. The soft rock tunnel floor reinforcement method according to claim 1, characterized in that: In the step S1, at least a portion of the multiple grouting pipes (20) are arranged to extend downward into the base plate (10), so that the concrete material fills the delamination fissures (12) below the base plate (10) to increase the strength of the stratum below the base plate (10).

6. The soft rock tunnel floor reinforcement method according to claim 1, characterized in that: In step S2, when driving anchor rods and / or anchor cables (43), the lengths of the multiple anchor rods and / or multiple anchor cables (43) used are different or the same; the inner diameter of the hole where the anchor rods and / or the anchor cables (43) are located changes along the extension direction thereof, so that the fitting relationship between the anchor rods and / or the anchor cables (43) and the inner wall of the hole changes along the extension direction thereof, and the fitting relationship includes interference fit, transition fit and clearance fit.

7. The soft rock tunnel floor reinforcement method according to claim 1, characterized in that: In the step S2, the W-shaped steel belt (41) is extended in a direction parallel to the extension direction of the tunnel, and a plurality of the W-shaped steel belts (41) are arranged in parallel and spaced apart; the circular steel belt (42) is extended in a direction perpendicular to the extension direction of the tunnel, and a plurality of the circular steel belts (42) are arranged in parallel and spaced apart; at least a portion of the circular steel belt (42) is arranged crosswise with at least a portion of the W-shaped steel belt (41), and anchor rods and / or anchor cables (43) are installed at the intersection of one circular steel belt (42) and one W-shaped steel belt (41), so that the steel mesh (40), the circular steel belt (42), and the W-shaped steel belt (41) are respectively tensioned into one with the anchor rods and / or the anchor cables (43).

8. The soft rock tunnel floor reinforcement method according to claim 1, characterized in that: The thickness of the first concrete layer (30) is not greater than the thickness of the second concrete layer (60), and the thickness of the second concrete layer (60) is not greater than the thickness of the third concrete layer (80).

9. The soft rock tunnel floor reinforcement method according to claim 1, characterized in that: In the step S2, driving the anchor cable (43) or the anchor rod comprises the following steps: drilling a casing hole (90) on the first concrete layer (30), then drilling an anchor hole (91) downward in the casing hole (90), wherein the hole diameter of the anchor hole (91) is smaller than that of the casing hole (90), and installing the anchor cable (43) or the anchor rod and a resin roll (92) inside the anchor hole (91), so that the resin roll (92) fixes the anchor cable (43) or the anchor rod, and then A fixing sleeve (93) is installed outside the anchor cable (43) or the anchor rod, and at least a portion of the fixing sleeve (93) is limitedly matched with the inner wall of the casing hole (90); then a grouting stopper (94) for grouting is installed at the outlet of the casing hole (90), and the concrete material is controlled to pass through the grouting stopper (94) into the casing hole (90) and the anchor hole (91) for grouting and solidification, so as to fix the anchor cable (43) or the anchor rod in the stratum.

10. The soft rock tunnel floor reinforcement method according to claim 9, characterized in that: In the step S2, after the concrete material solidifies in the casing hole (90) and the anchor hole (91), a tray (95) is installed on one end of the anchor cable (43) or the anchor rod located on the first mesh layer (50), so that the tray (95) is located above the W-shaped steel belt (41) and the circular steel belt (42) and is connected to the anchor cable (43) or the anchor rod; then, at one end of the anchor cable (43) or the anchor rod located on the first mesh layer (50), the tray (95) is installed on the first mesh layer (50). The spherical pad (96) and the lock (97) are assembled one by one, so that the two ends of the spherical pad (96) are respectively in contact with the lock (97) and the tray (95), and the lock (97) locks the spherical pad (96) and the tray (95) on the anchor cable (43) or the anchor rod, and the anchor cable (43) or the anchor rod presses the steel mesh (40), the circular steel belt (42), and the W-shaped steel belt (41) onto the first concrete layer (30).

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