Anti-bonding steel pipe concrete supporting system and construction process

Abstract

The application discloses a yielding anti-bonding steel pipe concrete supporting system and a construction process, relates to the technical field of underground engineering supporting, and comprises a steel arch, wherein the steel arch comprises a plurality of special-shaped steel pipes arranged in a ring direction; the special-shaped steel pipe comprises a special-shaped steel pipe body, a yielding pipe and a bag are sequentially arranged on the special-shaped steel pipe body towards a surrounding rock side, the special-shaped steel pipe body is provided with a main body grouting hole, and the main body grouting hole is used for injecting fine solid concrete into the inner chamber of the special-shaped steel pipe body; the yielding pipe is provided with a yielding grouting hole, the yielding pipe and the bag are communicated through a bag grouting hole, and the yielding grouting hole is used for injecting compressible concrete into the yielding pipe and the bag, so that the bag is expanded to form an initial supporting interface. The application combines bag adhesion, concrete filling and dynamic reinforcement, and improves the reliability, adaptability and construction compatibility of the supporting structure.

Description

Technical Field

[0001] This invention relates to the field of underground engineering support technology, and in particular to a steel-concrete composite support system and construction process. Background Technology

[0002] The geological environment faced by tunnel construction is becoming increasingly complex, with ultra-deep soft rock fracture zones constantly emerging. The "yielding" and "resistance" support concepts are important approaches to supporting tunnels in soft rock fracture zones. Steel-concrete composite supports offer the advantage of high support rigidity and are a key choice for supporting soft rock fracture zones. However, the following problems often exist in the process of using steel-concrete composite supports, which restrict their support effectiveness: (1) Steel-concrete composite has high stiffness and low compressive deformation capacity, and requires the use of compressive anchor cables during construction; (2) Due to the influence of concrete filling technology and material shrinkage, steel-concrete composite is prone to problems of incomplete filling, which affects its bearing capacity; (3) Steel-concrete composite has weak adhesion to the surrounding rock and slow welding speed to the steel mesh. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide an anti-bonded steel pipe concrete support system and construction process that improves the reliability, adaptability, and construction compatibility of the support structure through bag bonding, concrete filling, and dynamic reinforcement.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, embodiments of the present invention provide a steel-concrete composite support system, comprising a steel arch frame, the steel arch frame comprising a plurality of irregularly shaped steel pipes arranged sequentially along a circumferential direction; each irregularly shaped steel pipe comprises an irregularly shaped steel pipe body, with a pressure-relief pipe and a bladder arranged sequentially on the side of the irregularly shaped steel pipe body facing the surrounding rock; the irregularly shaped steel pipe body is provided with a main grouting hole for injecting fine concrete into the internal cavity of the irregularly shaped steel pipe body; the pressure-relief pipe is provided with a pressure-relief grouting hole, and the pressure-relief pipe and the bladder are connected through a bladder grouting hole, the pressure-relief grouting hole for injecting compressible concrete into the pressure-relief pipe and the bladder to cause the bladder to expand and form an initial support interface.

[0005] As a further implementation, compensation pipes are symmetrically fixed on both sides of the main body of the irregular steel pipe, and the compensation pipes are provided with compensation grouting holes for injecting compensation grout into the compensation pipes. A one-way valve is installed between the compensation pipe and the internal cavity of the shaped steel pipe body.

[0006] As a further implementation, the main body of the irregular steel pipe, the pressure relief pipe, and the compensation pipe are set at the same height.

[0007] As a further implementation, the main body of the irregularly shaped steel pipe is also provided with an exhaust port.

[0008] As a further implementation, one side surface of the pressure-relief pipe connected to the main body of the irregular steel pipe is a plane, and the other side surface is an arc surface.

[0009] As a further implementation, the pressure relief tube has a concave structure, and the bladder is fixed to the concave side of the pressure relief tube.

[0010] As a further implementation, multiple steel arch frames are provided, and adjacent steel arch frames are connected by longitudinal steel bars.

[0011] As a further implementation, concrete is sprayed onto the outer side of the steel arch frame and the surface of the surrounding rock to form a composite support structure of surrounding rock-concrete-steel arch frame.

[0012] Secondly, embodiments of the present invention also provide a construction process for a steel-concrete composite support system, comprising: Install the steel arch frame and attach the bag to the outside of the irregular steel pipe; Compressible concrete is injected into the pressure relief pipe and the bladder, causing the bladder to expand and fit tightly against the surrounding rock. Fine concrete grout is injected into the main body of the irregularly shaped steel pipe, and concrete curing is carried out. After the concrete has been cured to the design strength, compensating grout is injected into the compensation. The compensating grout enters the main body of the special-shaped steel pipe through a one-way valve for reinforcement. Longitudinal steel bars are welded between adjacent steel arch frames to form a complete support system.

[0013] As a further implementation method, after welding the longitudinal reinforcing bars, spray concrete onto the outside of the steel arch frame and the surface of the surrounding rock.

[0014] The beneficial effects of this invention are as follows: (1) The steel arch frame of the present invention includes a plurality of irregular steel pipes arranged in sequence along the circumference. The irregular steel pipe includes an irregular steel pipe body. The irregular steel pipe body is provided with a pressure relief pipe and a bladder. By injecting compressible concrete into the pressure relief pipe and the bladder, the bladder expands, thereby achieving a tight fit between the irregular steel pipe and the irregular surrounding rock, eliminating interface gaps, avoiding stress concentration, and improving the uniformity of force transmission. Fine concrete is injected into the irregular steel pipe body to enhance the support strength of the irregular steel pipe and improve the reliability of the support structure.

[0015] (2) The present invention provides compensation pipes on both sides of the main body of the irregular steel pipe. The compensation grout is injected into the main body of the irregular steel pipe through the compensation pipe to precisely reinforce the concrete inside the main body of the irregular steel pipe. The compressible concrete pressure layer and the compensation grout work together to achieve active pressure release of the surrounding rock stress and dynamic reinforcement of concrete shrinkage, ensuring long-term synergistic stress of "steel pipe-concrete-surrounding rock", so that the steel arch frame can resist the surrounding rock pressure and prevent structural deformation and collapse. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is a schematic diagram of the overall structure of the support system according to one or more embodiments of the present invention; Figure 2 This is a schematic diagram of the irregular steel pipe structure according to one or more embodiments of the present invention; Figure 3 This is a cross-sectional view of the irregular steel pipe according to one or more embodiments of the present invention; Figure 4 This is a schematic diagram of the arrangement of the outer side of the steel arch frame and the surrounding rock according to one or more embodiments of the present invention.

[0018] Among them, 1. Bag; 2. Bag grouting hole; 3. Shaped steel pipe body; 4. Steel pipe body chamber; 5. Vent hole; 6. Body grouting hole; 7. Compensation pipe; 8. Compensation chamber; 9. Compensation grouting hole; 10. One-way valve; 11. Pressure relief pipe; 12. Pressure relief chamber; 13. Pressure relief grouting hole; 14. Longitudinal reinforcement; 15. Surrounding rock; 16. Steel arch frame; 17. CERF compressible concrete; 18. Fine concrete; 19. Ultrafine epoxy resin compensation liquid. Detailed Implementation

[0019] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] For ease of description, the terms "inner," "outer," "left," and "right" appearing in this invention only indicate that they are consistent with the inner, outer, left, and right directions of the accompanying drawings themselves. They do not limit the structure and are merely for the purpose of facilitating the description of this invention and simplifying the description. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Example 1: This embodiment provides a steel-concrete composite support system with anti-bonding properties, such as... Figures 1-4 As shown, it mainly includes steel arch frames 16, pockets 1 and longitudinal steel bars 14. Multiple steel arch frames 16 are arranged along the length of underground structures such as tunnels and roadways. Adjacent steel arch frames 16 are connected by longitudinal steel bars 14. Concrete is sprayed on the outer side of the steel arch frames 16 and the surface of the surrounding rock 15 to form a composite support structure of surrounding rock-concrete-steel arch frames.

[0022] The steel arch frame 16 includes multiple irregularly shaped steel pipes arranged circumferentially along the surrounding rock 15. Each irregularly shaped steel pipe is equipped with a bladder 1. Grouting into the bladder 1 allows it to expand and form an initial support interface. The irregularly shaped steel pipes also have pressure relief pipes 11. The bladder 1 and the irregularly shaped steel pipes work together to form a support structure of "pressure relief and load bearing".

[0023] Specifically, such as Figure 2 As shown, the shaped steel pipe includes a shaped steel pipe body 3, a pressure relief pipe 11, and a compensation pipe 7. In this embodiment, the cross-section of the shaped steel pipe body 3 is a D-shaped structure, with the side closer to the surrounding rock 15 as the outer side. The outer wall of the shaped steel pipe body 3 is a plane, and the inner wall is an arc surface. The arc surface of the shaped steel pipe body 3 protrudes inward. The D-shaped structure of the shaped steel pipe body 3 can further improve the bending modulus of the cross section and enhance the bending resistance of the structure under high surrounding rock 15 pressure.

[0024] The main body 3 of the irregular steel pipe has a pre-reserved main grouting hole 6 and an exhaust hole 5. The main grouting hole 6 is used to inject high-strength fine concrete 18 into the main body cavity 4 of the steel pipe. The purpose of setting the exhaust hole 5 is to ensure that air in the main body cavity 4 of the steel pipe is discharged during the concrete pouring process, so as to avoid the formation of voids due to residual air bubbles. The setting positions of the main grouting hole 6 and the exhaust hole 5 can be selected according to actual requirements. In this embodiment, the main grouting hole 6 and the exhaust hole 5 are set on the left or right side wall of the main body 3 of the irregular steel pipe, and the exhaust hole 5 is set near the top of the main body 3 of the irregular steel pipe, and the main grouting hole 6 is set near the bottom of the main body 3 of the irregular steel pipe; the diameter of the exhaust hole 5 is smaller than the diameter of the main grouting hole 6. It is understood that in other embodiments, multiple exhaust holes 5 and grouting holes can be set. At the same time, the pipe wall of the main body 3 of the irregular steel pipe also has a reserved assembly interface to provide installation positions for other components.

[0025] like Figures 2-4 As shown, a pressure relief pipe 11 is fixed to the outer wall of the shaped steel pipe body 3. In this embodiment, the pressure relief pipe 11 is at the same height as the shaped steel pipe body 3, and the width of the pressure relief pipe 11 is greater than the width of the shaped steel pipe body 3. In this embodiment, the pressure relief pipe 11 has a concave structure, and its side away from the shaped steel pipe body 3 has a recessed part, which can increase the amount of slurry filling in the bag 1.

[0026] The pressure relief pipe 1 is fixed to the outside of the pressure relief pipe 11. The pipe wall of the pressure relief pipe 11 where the pressure relief pipe 1 is installed has a pressure relief grouting hole 2. At the same time, the side wall of the pressure relief pipe 11 is provided with a pressure relief grouting hole 13, which is located near the bottom of the pressure relief pipe 11. CERF compressible concrete 17 is injected into the pressure relief chamber 12 inside the pressure relief pipe 11 through the pressure relief grouting hole 13. The CERF compressible concrete 17 enters the pressure relief pipe 1 through the pressure relief grouting hole 2, which can release the stress of the surrounding rock 15 to achieve dynamic synergistic force bearing, and also allow the pressure relief pipe 1 to expand to form the initial support interface.

[0027] In this embodiment, the bag 1 is made of polyester fiber reinforced rubber, which has high elasticity, puncture resistance and damage resistance. The bag 1 can expand with the grouting pressure to adapt to the irregular surrounding rock 15.

[0028] like Figures 2-4 As shown, compensation pipes 7 are symmetrically arranged on the left and right sides of the main body 3 of the irregular steel pipe. In order to avoid the connection position of the longitudinal reinforcing bars 14, the compensation pipes 7 are arranged close to the arc surface of the main body 3 of the irregular steel pipe. The compensation pipe 7 has a compensation chamber 8 inside, and there is a communication port between the compensation chamber 8 and the main body chamber 4 of the steel pipe. A one-way valve 10 is installed at the communication port to allow the slurry to be injected into the compensation chamber 8 in one direction without backflow.

[0029] The compensation pipe 7 has a grouting hole 9 near the bottom on its side wall. Ultra-fine epoxy resin grout is injected into the compensation chamber 8 through the grouting hole 9. Under the action of the one-way valve 10, the ultra-fine epoxy resin grout enters the main steel pipe chamber 4, precisely reinforcing the voids caused by concrete shrinkage within the main steel pipe chamber 4. In this embodiment, the compensation pipe 7 is a square pipe of the same height as the shaped steel pipe body 3, enhancing the bonding stability between it and the side wall of the shaped steel pipe body 3. Of course, in other embodiments, the compensation pipe 7 can also be a round pipe or other shapes.

[0030] This embodiment achieves a tight fit between the irregular steel pipe and the irregular surrounding rock 15 through the grouting expansion design of the bladder 1, eliminating interface gaps, avoiding stress concentration, and improving the uniformity of force transmission; it integrates the CERF compressible concrete 17 pressure-relieving layer and the ultra-fine epoxy compensation grout system, which can not only actively relieve the stress of the surrounding rock 15, but also dynamically reinforce the shrinkage of the concrete, ensuring the long-term coordinated stress of "steel pipe-concrete-surrounding rock 15".

[0031] This embodiment can be adapted to various underground projects such as tunnels, roadways, and underground utility tunnels, and is especially suitable for complex geological conditions such as soft rock and high ground stress, with significant support effect.

[0032] Example 2: This embodiment provides a construction process for a reinforced steel-concrete composite support system, based on the support system described in Embodiment 1, including the following steps: Step 1: Tunnel Excavation The tunnel cross-section was excavated in accordance with the underground engineering construction specifications. The surface of the surrounding rock 15 was cleaned of loose debris and dangerous rocks, and the rock wall was repaired to ensure that there were no loose blocks on the surface of the surrounding rock 15.

[0033] Step 2: Install the steel arch frame 16: The segmented irregular steel pipes are assembled by connecting steel plates and high-strength bolts. Temporary support devices are used to fix the steel arch frame 16 in the design position. The elevation, spacing and verticality of the steel arch frame 16 are corrected to ensure that they meet the support design requirements. At the same time, the bag 1 is pasted on the outside of the irregular steel pipe to ensure that the installation is firm and the seal is reliable.

[0034] Step 3: Grouting chamber 12: After the steel arch frame 16 is installed and fixed, CERF compressible concrete 17 is injected into the pressure chamber 12 and the bag 1 through the pressure injection hole 13. The injected grout causes the bag 1 to expand, so that the steel arch frame 16 fits tightly with the surrounding rock 15. At the same time, with the help of the controllable plastic deformation capability of CERF compressible concrete 17, the structure and the surrounding rock 15 can be dynamically and collaboratively stressed.

[0035] Step 4: Grouting of steel pipes: After the pressure chamber 12 is constructed, high-strength fine concrete grout 18 is injected into the main steel pipe chamber 4 through the main grouting hole 6. During the grouting process, air is discharged through the vent hole 5 to ensure that the concrete is filled densely. After the grouting is completed, the concrete is cured in accordance with the specifications to ensure that the concrete strength meets the standards.

[0036] Step 5: Inspection and Reinforcement After the concrete in the main cavity 4 of the steel pipe has cured to the design strength, a comprehensive inspection is carried out on the installation accuracy of the steel arch frame 16, the density of the concrete, the fit of the bladder 1, and the structural sealing. After the inspection is qualified, the corresponding vent hole 5, the main grouting hole 6, and the pressure relief grouting hole 13 of the steel pipe are sealed. Ultra-fine epoxy resin compensation grout is injected into the compensation cavity 8 through the compensation grouting hole 9. Under the action of the one-way valve 10, the voids caused by the shrinkage of the concrete inside the main body 3 of the irregular steel pipe are precisely reinforced. Finally, the compensation grouting hole 9 is sealed.

[0037] If defects are found during inspection, reinforcement measures such as grouting and strengthening should be taken in a timely manner.

[0038] Step 6: Weld longitudinal reinforcing bars 14: After the steel arch frame 16 is inspected and reinforced, longitudinal steel bars 14 are welded between the main limb angle steels of adjacent steel arch frames 16 to form a continuous and complete support system, thereby improving the overall support stiffness and stability.

[0039] Step 7: Shotcrete: Shot concrete is sprayed onto the outer side of the steel arch frame 16 and the surface of the surrounding rock 15, fully covering the steel arch frame 16, the bag 1, and the surrounding rock 15, forming a composite support structure in which the surrounding rock 15, shot concrete, and steel arch frame 16 work together to enhance the integrity and load-bearing capacity of the support system.

[0040] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A steel-concrete composite support system for resisting bonding, characterized in that, The system includes a steel arch frame comprising multiple irregularly shaped steel pipes arranged sequentially along a circumferential direction. Each irregularly shaped steel pipe includes a main body, with a pressure-relief pipe and a grouting bag sequentially arranged on the side of the main body facing the surrounding rock. The main body of the irregularly shaped steel pipe is provided with a main grouting hole for injecting fine concrete into the internal cavity of the main body. The pressure-relief pipe is provided with a pressure-relief grouting hole, and the pressure-relief pipe and the grouting bag are connected through a grouting hole in the grouting bag. The pressure-relief grouting hole is used to inject compressible concrete into the pressure-relief pipe and the grouting bag to cause the grouting bag to expand and form an initial support interface. The main body of the irregular steel pipe is symmetrically fixed with compensation pipes on both sides. The compensation pipes are provided with compensation grouting holes, which are used to inject compensation grout into the compensation pipes. A one-way valve is installed between the compensation pipe and the internal cavity of the shaped steel pipe body; The main body of the irregular steel pipe is connected to the pressure relief pipe. One side of the surface is flat, and the other side is an arc surface; the cross-section of the main body of the irregular steel pipe is a D-shaped structure. Ultra-fine epoxy resin grout is injected into the compensation chamber through the compensation grouting hole. Under the action of the one-way valve, the voids caused by the shrinkage of the concrete inside the irregular steel pipe body are precisely reinforced.

2. The anti-bonding steel-concrete composite support system according to claim 1, characterized in that, The main body of the irregular steel pipe, the pressure relief pipe, and the compensation pipe are set at the same height.

3. The anti-bonding steel-concrete composite support system according to claim 1, characterized in that, The main body of the irregularly shaped steel pipe is also provided with an exhaust port.

4. The anti-bonding steel-concrete composite support system according to claim 1, characterized in that, The pressure relief tube has a concave structure, and the bladder is fixed to the concave side of the pressure relief tube.

5. The anti-bonding steel-concrete composite support system according to claim 1, characterized in that, Multiple steel arch frames are provided, and adjacent steel arch frames are connected by longitudinal steel bars.

6. A steel-concrete composite support system according to claim 5, characterized in that, Concrete is sprayed onto the outer side of the steel arch frame and the surface of the surrounding rock to form a composite support structure of surrounding rock-concrete-steel arch frame.

7. The construction process of a steel-concrete composite support system according to any one of claims 1-6, characterized in that, include: Install the steel arch frame and attach the bag to the outside of the irregular steel pipe; Compressible concrete is injected into the pressure relief pipe and the bladder, causing the bladder to expand and fit tightly against the surrounding rock. Fine concrete grout is injected into the main body of the irregularly shaped steel pipe, and concrete curing is carried out. After the concrete has been cured to the design strength, compensating grout is injected into the compensation. The compensating grout enters the main body of the special-shaped steel pipe through a one-way valve for reinforcement. Longitudinal steel bars are welded between adjacent steel arch frames to form a complete support system.

8. The construction process of a steel-concrete composite support system according to claim 7, characterized in that, After welding the longitudinal reinforcing bars, spray concrete onto the outside of the steel arch frame and the surface of the surrounding rock.

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