Construction method for pressure concrete pouring of secondary lining of tunnel

Abstract

The invention provides a construction method for pressure concrete pouring of a secondary lining of a tunnel. The construction method comprises the following steps that (1) construction preparation is conducted, the center level is measured, a short side wall base top is repaired and chiseled, and a lining trolley track is laid; (2) positioning and erecting a formwork, adjusting the elevation of an arch part and the center line of the arch part by using a hydraulic jack, and adjusting the clearance of a side wall; (3) pouring concrete, pumping the concrete into a mold through front and rear pouring openings for layered pouring, and enabling a concrete conveying pipe to enter the mold from the middle pouring opening of the arch crown to extrude the front and rear ends; and (4) demolding and curing are conducted, specifically, after concrete pouring is completed, timely and timed curing is conducted. The full-hydraulic integral type formwork trolley is adopted for operation, the concrete mixing truck is adopted for transportation of concrete in trackless transportation, the concrete conveying pump pumps the concrete into a formwork, and the construction efficiency can be improved while the construction quality is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, in particular to a construction method of pressure-cast concrete for secondary lining of a tunnel. Background Art

[0002] Secondary lining is cast concrete or reinforced concrete lining applied inside the primary support during tunnel construction, and together with the primary support, it forms a composite lining. Its main functions include strengthening support, optimizing route drainage system, beautifying appearance, and facilitating the installation of communication, lighting, monitoring and other facilities to meet the requirements of modern highway tunnel construction.

[0003] In tunnel construction, secondary lining, as opposed to primary support, refers to the inner lining constructed with materials such as concrete after the tunnel has been primary supported. This design not only improves the safety of the tunnel, but also enhances its functionality and aesthetics.

[0004] A Chinese patent discloses a method for supplementary grouting of a tunnel secondary lining (application number 201910734035.0), which includes the following steps: S1. Prepare the supplementary grouting slurry for the tunnel secondary lining according to the required fluidity and initial and final setting time; S2. Install the grouting pipe at the tunnel vault; S3. Set up the tunnel secondary lining supplementary grouting thickness detection equipment and set its ultrasonic detection device probe on the vault; S4. Perform supplementary grouting of the tunnel secondary lining, monitor the supplementary grouting in real time through the tunnel secondary lining supplementary grouting thickness detection equipment, and adjust the grouting amount in real time according to the monitoring value. However, its construction quality is not high and the construction period is long. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a construction method for pressure-casting concrete for secondary lining of a tunnel, so as to solve the problems raised in the above-mentioned background technology.

[0006] The technical problem solved by the present invention is achieved by adopting the following technical solution: A construction method of pressure-casting concrete for secondary lining of a tunnel, comprising the following steps:

[0007] Step (1). Construction preparation, center level measurement, low side wall foundation top chiseling, lining trolley track laying;

[0008] Step (2). Position the mold and use a hydraulic jack to adjust the arch elevation, arch centerline, and side wall clearance;

[0009] Step (3) pouring concrete, pumping concrete through the front and rear pouring ports into the mold layered pouring, the concrete delivery pipe from the middle of the arch pouring port into the mold to the front and rear ends of the extrusion;

[0010] Step (4). De-moulding and curing: after concrete pouring is completed, timely and regular curing is carried out.

[0011] Furthermore, in step (2), the template should be rust-free and polished before installation. The template surface is required to be flat, the dimensional deviation meets the design requirements, and it has sufficient rigidity, strength, and stability. It is also required to be easy to assemble and disassemble and the joints are tight and leak-proof.

[0012] Furthermore, after the formwork is installed in step (2), the axis and elevation are checked to meet the design requirements and then reinforced to ensure that the formwork does not deform or shift after being subjected to force during the concrete pouring process.

[0013] Furthermore, in the step (2), the mold is clean and free of debris, the assembly is flat and tight, the vertical and flat surfaces of the support structure are firmly installed, and can withstand accidental impact during vibration, the support columns are fixed in two mutually perpendicular directions, and scissor struts are arranged in the vertical and horizontal directions to connect the vertical and horizontal steel pipe supports, the support part of the support is placed on a solid foundation, and after the template is inspected and qualified, a mold release agent is applied.

[0014] Furthermore, in step (2), the formwork should be carefully repaired and leveled, any unevenness should be leveled, the welds should be repaired and polished, and the fasteners should be tightened before pouring concrete.

[0015] Furthermore, in step (3), before pouring, the support, formwork, steel bars and embedded parts are inspected, and the debris, accumulated water in the formwork and dirt on the steel bars are cleaned; the gaps in the formwork are tightly filled and a release agent is applied to the inner surface.

[0016] Furthermore, during the pouring of concrete in step (3), the position of the formwork, steel bars and embedded components and the size of the protective layer should be checked regularly to ensure that they are in the correct position and not deformed. Attention should be paid to the support conditions of the formwork, brackets, etc., and a dedicated person should be assigned to check. If there is any deformation, displacement or sinking, it should be corrected and reinforced immediately.

[0017] Furthermore, in step (3), concrete is mixed centrally by a mixing station, which uses computer automatic metering, and is transported by a concrete truck. The concrete is pumped into the mold by a concrete pump, and two 60m3 / h concrete pumps are used to pour the concrete symmetrically on both sides in layers, with tamping windows reserved, and the concrete is compacted in layers by vibration; tamping is performed by combining a vibrator attached to the template trolley and an inserted vibrator.

[0018] Furthermore, in the step (3), the secondary lining construction sequence is: first lay the base, then cast the wall and the arch, the first invert is cast once, the invert, the side wall foundation and the initial support together form a closed loop, and the side wall and arch concrete are constructed from the opening to the inside.

[0019] Compared with the prior art, the beneficial effects of the present invention are: the present invention adopts a fully hydraulic integral formwork trolley for operation, a trackless transport adopts a concrete mixer truck to transport concrete, and a concrete delivery pump pumps concrete into the mold, which can improve construction efficiency while ensuring construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the method flow of the present invention. DETAILED DESCRIPTION

[0021] In order to make the technical means for realizing the present invention, the creative features, the objectives and effects to be achieved easy to understand, the present invention is further explained below in conjunction with specific diagrams. In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection, or an integral connection can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be internal communication between two elements.

[0022] Example 1

[0023] like Figure 1 As shown, a construction method of pressure-casting concrete for secondary lining of a tunnel comprises the following steps:

[0024] Step (1). Construction preparation, center level measurement, low side wall foundation top chiseling, lining trolley track laying;

[0025] Step (2). Position the mold and use a hydraulic jack to adjust the arch elevation, arch centerline, and side wall clearance;

[0026] Step (3) pouring concrete, pumping concrete through the front and rear pouring ports into the mold layered pouring, the concrete delivery pipe from the middle of the arch pouring port into the mold to the front and rear ends of the extrusion;

[0027] Step (4). De-moulding and curing: after concrete pouring is completed, timely and regular curing is carried out.

[0028] Before the template is installed in step (2), it should be rust-free and polished. The template surface should be flat, the dimensional deviation should meet the design requirements, it should have sufficient rigidity, strength, stability, and be easy to disassemble and assemble, and the joints should be tight and leak-proof. After the template is installed in step (2), check that the axis and elevation meet the design requirements and then reinforce it to ensure that the template does not deform or shift after being stressed during the concrete pouring process. In step (2), the mold is clean and free of debris, the splicing is flat and tight, the vertical and flat surfaces of the support structure are firmly installed, and can withstand accidental impact during vibration. The support columns are fixed in two mutually perpendicular directions, and scissor braces are set in the vertical and horizontal directions to connect the vertical and horizontal steel pipe supports. The support part of the support is placed on a solid foundation. After the template is inspected and qualified, a release agent is applied. In step (2), the template should be carefully repaired and smoothed, unevenness should be tied flat, open welds should be repaired and polished, and fasteners should be tightened before concrete can be poured.

[0029] Example 2

[0030] like Figure 1 As shown, a construction method of pressure-casting concrete for secondary lining of a tunnel comprises the following steps:

[0031] Step (1). Construction preparation, center level measurement, low side wall foundation top chiseling, lining trolley track laying;

[0032] Step (2). Position the mold and use a hydraulic jack to adjust the arch elevation, arch centerline, and side wall clearance;

[0033] Step (3) pouring concrete, pumping concrete through the front and rear pouring ports into the mold layered pouring, the concrete delivery pipe from the middle of the arch pouring port into the mold to the front and rear ends of the extrusion;

[0034] Step (4). De-moulding and curing: after concrete pouring is completed, timely and regular curing is carried out.

[0035] In step (3), before pouring, the bracket, formwork, steel bar and embedded parts are checked, and the sundries, accumulated water and dirt on the steel bar in the formwork are cleaned; the gaps in the formwork are tightly filled, and the inner surface is coated with a release agent. In the process of pouring concrete in step (3), the position of the formwork, steel bar and embedded parts and the size of the protective layer should be checked frequently to ensure that their positions are correct and not deformed, and attention should be paid to the support conditions of the formwork, bracket, etc., and a special person should be assigned to check. If there is deformation, displacement or sinking, it should be corrected and reinforced immediately. In step (3), the concrete is mixed centrally by the mixing station, the mixing station uses computer automatic metering, the concrete is transported by a concrete transport truck, and the concrete is pumped into the mold by a concrete delivery pump. Two 60m3 / h delivery ground pumps are used to pour in layers and symmetrically on both sides, and a tamping window is reserved for layered compaction; tamping is achieved by the combined vibration of the attached vibrator and the inserted vibrator on the formwork trolley. The secondary lining construction sequence in step (3) is as follows: first lay the base, then cast the wall and the arch, first cast the inverted arch once, the inverted arch and the side wall foundation and the initial support together form a closed loop, and the side wall and arch concrete are constructed from the opening to the inside.

[0036] The present invention uses a walking multifunctional trolley as a working platform, manually installs permeable pipes, hangs waterproof boards, and adopts nail-free hanging for waterproof layers. A trestle overhead line is adopted to construct the inverted arch and the bottom in advance. The arch wall lining adopts a fully hydraulic integral formwork trolley, and the trackless transportation adopts a concrete mixer truck to transport concrete, and the concrete delivery pump pumps the concrete into the mold. The arch is constructed according to the capping process, and the intermittent and capping top surfaces should be radial. Grouting holes are reserved in the arch, and the cavities are backfilled and grouting is performed to ensure that the arch concrete is dense; the demolding time of the secondary lining is strictly controlled.

[0037] Composite lining is used in variable cross-section sections. Under normal circumstances, secondary lining should be constructed after the deformation of surrounding rock and initial support is basically stable. The basic stability of deformation should be in line with the obvious slowing trend of displacement speed around the tunnel. The horizontal displacement speed of the arch foot clearance is less than 0.2mm / d, and the sinking speed of the arch crown is less than 0.15mm / d.

[0038] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A construction method for pressure-casting concrete for secondary tunnel lining, characterized in that: The following steps are involved: Step (1). Construction preparation, center level measurement, low side wall foundation top chiseling, lining trolley track laying; Step (2). Position the mold and use a hydraulic jack to adjust the arch elevation, arch centerline, and side wall clearance; Step (3) pouring concrete, pumping concrete through the front and rear pouring ports into the mold layered pouring, the concrete delivery pipe from the middle of the arch pouring port into the mold to the front and rear ends of the extrusion; Step (4). De-moulding and curing: after concrete pouring is completed, timely and regular curing is carried out.

2. The construction method of a tunnel secondary lining pressure pouring concrete according to claim 1, characterized in that: In the step (2), the template should be rust-free and polished before installation. The template surface should be flat, the dimensional deviation should meet the design requirements, it should have sufficient rigidity, strength and stability, and it should be easy to disassemble and assemble, and the joints should be tight and leak-proof.

3. The construction method of pressure-casting concrete for secondary tunnel lining according to claim 1 is characterized by: After the template is installed in step (2), check that the axis and elevation meet the design requirements and then reinforce it to ensure that the template does not deform or shift after being subjected to force during the concrete pouring process.

4. The construction method of pressure-casting concrete for secondary tunnel lining according to claim 1 is characterized by: In the step (2), the mold is clean and free of debris, the assembly is flat and tight, the vertical and flat surfaces of the support structure are firmly installed, and can withstand accidental impact during vibration. The support columns are fixed in two mutually perpendicular directions, and scissor braces are arranged in the vertical and horizontal directions to connect the vertical and horizontal steel pipe supports. The support part of the support is placed on a solid foundation. After the template is inspected and qualified, a mold release agent is applied.

5. The construction method of pressure-casting concrete for secondary tunnel lining according to claim 1 is characterized by: In step (2), the formwork should be carefully repaired and leveled, any unevenness should be leveled, the welds should be repaired and polished, and the fasteners should be tightened before pouring concrete.

6. The construction method of pressure-casting concrete for secondary tunnel lining according to claim 1 is characterized by: In the step (3), before pouring, the support, formwork, steel bars and embedded parts are inspected, and the debris, accumulated water in the formwork and dirt on the steel bars are cleaned; the gaps in the formwork are tightly filled and the inner surface is coated with a release agent.

7. The construction method of pressure-casting concrete for secondary tunnel lining according to claim 1 is characterized by: During the pouring of concrete in step (3), the position of the formwork, steel bars and embedded components and the size of the protective layer should be checked frequently to ensure that they are in the correct position and not deformed. Attention should be paid to the support conditions of the formwork, brackets, etc., and a dedicated person should be assigned to check. If there is any deformation, displacement or sinking, it should be corrected and reinforced immediately.

8. The construction method of pressure-casting concrete for secondary tunnel lining according to claim 1 is characterized by: In the step (3), concrete is mixed centrally by a mixing station, which uses computer automatic metering, and is transported by a concrete truck. The concrete is pumped into the mold by a concrete pump, and two 60m3 / h concrete pumps are used to pour the concrete in layers and symmetrically on both sides, with tamping windows reserved and layered vibration. The tamping is carried out by a vibrator attached to the template trolley and an inserted vibrator.

9. The construction method of pressure-casting concrete for secondary tunnel lining according to claim 1, characterized in that: The secondary lining construction sequence in step (3) is: first lay the base, then pour the wall and arch, first pour the inverted arch once, the inverted arch and the side wall foundation and initial support together form a closed loop, and the side wall and arch concrete are constructed from the opening to the inside.

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