Method for preventing void and pressure relief grouting of top arch of double lining steel form trolley

Abstract

The application discloses a kind of two lining steel mould trolley top arch pouring anti-void and pressure relief grouting method, 1, after top plate frame is set up, the inclined pipe top of pipe orifice on exhaust pipe is contacted with the inner side surface of arch top initial support concrete, then the exhaust pipe below top plate is connected with positioning seat by connecting piece;2, open concrete pouring opening by operating drive mechanism, connect external pump pipe with pouring concrete pipe lower pipe orifice by buckle;3, open concrete delivery pump, and two lining concrete is delivered to two lining concrete pouring area by pouring concrete pipe, when the concrete slurry in exhaust pipe is full pipe and flows out, stop two lining concrete pouring, the lower mouth of exhaust pipe is sealed by sealing plug, and concrete pouring opening is closed by operating drive mechanism, and external pump pipe is removed;4, after two lining concrete solidifies, open connecting piece and pull out exhaust pipe, and grouting is carried out in original hole, until the gap between two lining concrete pouring layer and initial support concrete is filled up.The application avoids the occurrence of void phenomenon.

Description

Technical Field

[0001] This invention relates to the casting of the roof arch of a secondary steel formwork platform, and more particularly to a method for preventing voids and relieving pressure during the casting of the roof arch of a secondary steel formwork platform. Background Technology

[0002] Steel formwork trolleys are widely used in secondary lining concrete pouring during tunnel construction. However, poor venting is a common problem during the construction of the arch section. This issue manifests primarily as poor gas venting, leading to voids in the arch section. After the secondary lining concrete is poured, internal gases fail to escape effectively, creating gaps between the concrete and the formwork. Furthermore, during the final arch sealing stage, the high pressure generated by the concrete pump makes it even more difficult to expel residual gas. This not only exacerbates the void problem but can also cause the arch formwork to deform under excessive pressure, severely impacting the stability and safety of the tunnel structure.

[0003] Besides the ventilation issue, the secondary lining concrete also experiences shrinkage after pouring and solidifying. This shrinkage causes gaps to appear between the outer surface of the secondary lining concrete layer and the inner surface of the primary support concrete. If these gaps are not addressed promptly, they may adversely affect the overall structural strength and durability of the tunnel. The traditional method is to drill grouting holes and then perform secondary grouting to fill these gaps. However, this method is not only time-consuming and labor-intensive but also costly and may cause some damage to the tunnel structure. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preventing voids and relieving pressure during the pouring of the arch of a secondary steel formwork trolley, which effectively solves the problem of voids occurring in the arch and reduces the construction cost of secondary grouting to fill the gaps.

[0005] To achieve the above objectives, the present invention can adopt the following technical solutions:

[0006] The method for preventing voids and relieving pressure during the casting of the roof arch of the secondary steel formwork platform described in this invention employs a special device for grouting construction.

[0007] The special device includes a vertically upward sealed exhaust pipe that penetrates the top formwork, with the upper opening of the exhaust pipe having an inclined opening structure; a concrete pouring port is provided on the top formwork, and a movable cover plate is provided at the concrete pouring port, the movable cover plate being slidably mounted on the surface of the top formwork; a concrete pouring pipe is fixed on the lower surface of the top formwork, located on one side of the exhaust pipe, with the upper opening of the concrete pouring pipe being fixedly connected to the concrete pouring port; a support plate and a positioning seat are fixed on the outer wall of the concrete pouring pipe, the support plate being provided with a drive mechanism for opening / closing the concrete pouring port, and the positioning seat being connected to the exhaust pipe located below the top formwork via a connector;

[0008] The casting method includes the following steps:

[0009] Step 1: After the top formwork is erected, the top of the inclined pipe opening of the exhaust pipe is brought into contact with the inner side of the initial support concrete of the arch. Then, the exhaust pipe under the top formwork is connected to the positioning seat through the connector.

[0010] Step 2: Operate the drive mechanism to open the concrete pouring port, and connect the external pump pipe to the lower pipe opening of the concrete pouring pipe through the buckle;

[0011] Step 3: Start the concrete delivery pump and transport the secondary lining concrete to the secondary lining concrete pouring area through the concrete pouring pipe. At the same time, start the vibrator attached to the lower surface of the top formwork for vibration. As the secondary lining concrete surface gradually rises, the gas in the secondary lining concrete pouring area is discharged from the inclined pipe of the exhaust pipe. When the secondary lining concrete surface rises to the top arch surface, some concrete slurry enters the exhaust pipe through the inclined pipe and flows out from the lower pipe opening. When the concrete slurry in the exhaust pipe is full, stop the secondary lining concrete pouring, seal the lower opening of the exhaust pipe with a sealing plug, operate the drive mechanism to close the concrete pouring port, and remove the external pump pipe.

[0012] Step 4: After the secondary lining concrete has solidified, open the connector, pull out the vent pipe, and grout at the original hole location until the gap between the secondary lining concrete pouring layer and the initial support concrete is filled.

[0013] Alternatively, the drive mechanism includes a rotating shaft hinged to the support plate, the rotating shaft passing vertically upward through the top mold plate and fixedly connected to the movable cover plate, and a handle fixed to the lower end of the rotating shaft.

[0014] Alternatively, the connector is a movable buckle, and the positioning seat is connected to the exhaust pipe located below the top mold plate via the movable buckle.

[0015] Alternatively, a sealing plate is fitted onto the exhaust pipe located below the top mold plate via a sealing ring, with the upper surface of the sealing plate in close contact with the lower surface of the top mold plate.

[0016] Alternatively, to facilitate the removal of the exhaust pipe from the solidified secondary lining concrete, a plastic wrap may be placed over the exhaust pipe.

[0017] This invention adds a vent pipe with an inclined opening to the side of the concrete pouring pipe. Therefore, during the concrete pouring period, gas within the secondary lining concrete pouring area is discharged through the inclined opening of the vent pipe, playing a crucial role in venting and depressurization, preventing voids. Simultaneously, during the arch sealing stage when the secondary lining concrete reaches its top, the full discharge of grout from the vent pipe provides a clear indication that the pouring is complete, thus improving construction efficiency and accuracy. Furthermore, after the secondary concrete has solidified, grouting material can be injected through the vent pipe opening to effectively fill the gap between the secondary lining concrete layer and the initial support concrete, eliminating the need for additional drilling of grouting holes. This not only simplifies the construction process and reduces construction costs but also improves the integrity and durability of the tunnel structure. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the special device structure described in this invention.

[0019] Figure 2 yes Figure 1 A schematic diagram of the AA-direction cross-sectional structure.

[0020] Figure 3 This is a schematic diagram of the concrete pouring port in the open state as described in this invention.

[0021] Figure 4 This is a schematic diagram of the closed state of the concrete pouring port according to the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Furthermore, the meaning of "and / or" throughout the text is to include three parallel solutions. Taking "A and / or B as an example" as an example, it includes solution A, solution B, or a solution that satisfies both A and B. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0026] like Figure 1-4 As shown, the grouting method for preventing voids and relieving pressure during the casting of the roof arch of the secondary steel formwork platform of the present invention uses a special device for grouting construction.

[0027] The special device includes a vent pipe 2 made of PVC material that is vertically sealed and passes through the top formwork 1. The upper opening of the vent pipe 2 is a downward-sloping oblique pipe structure. A concrete pouring port 3 is provided on the top formwork 1. A movable cover plate 4 is provided at the concrete pouring port 3 and is slidably mounted on the upper surface of the top formwork 1. A concrete pouring pipe 5 is welded to the lower surface of the top formwork 1 on one side of the vent pipe 2. The upper opening of the concrete pouring pipe 5 is fixedly connected to the concrete pouring port 3. A support plate 6 and a positioning seat 7 are fixed on the outer wall of the concrete pouring pipe 5. The support plate 6 is provided with a drive mechanism for opening / closing the concrete pouring port. The positioning seat 7 is connected to the vent pipe 2 located below the top formwork 1 through a connector.

[0028] Advantageously or exemplary, the drive mechanism includes a rotating shaft 8 hinged to the support plate 6, the rotating shaft passing vertically upward through the top mold plate 1 and fixedly connected to the movable cover plate 4, and a handle 9 fixed to the lower end of the rotating shaft 8 to facilitate operation of the movable cover plate 4 to open / close the concrete pouring port.

[0029] Advantageously or exemplary, the connector is a movable buckle 10; one end of the movable buckle is screwed to the positioning seat 7 by a bolt, and the other end is connected to the positioning seat 7 by a pin and a cotter pin, so that the exhaust pipe 2 located below the top mold plate 1 and the positioning seat 7 can be detachably connected by the movable buckle 10.

[0030] Ideally or exemplary, a sealing plate 12 is fitted onto the exhaust pipe 2 located below the top formwork 1 via a sealing ring 11. The upper surface of the sealing plate 12 is in close contact with the lower surface of the top formwork 1 to prevent grout from flowing out from the gap between the top formwork 1 and the outer wall of the exhaust pipe 2 during the second-stage concrete pouring process.

[0031] Advantageously or exemplary, the exhaust pipe 2 is covered with plastic wrap, which facilitates the removal of the exhaust pipe 2 from the solidified secondary concrete.

[0032] The grouting method includes the following steps:

[0033] Step 1: After the top formwork 1 is erected, the top of the inclined pipe opening of the exhaust pipe 2 is brought into contact with and pressed against the inner side of the initial support concrete 13 of the arch. Then, the exhaust pipe 2 below the top formwork 1 is connected and positioned to the positioning seat 7 through the movable buckle 10.

[0034] Step 2: Operate the movable cover plate 4 using handle 9 to open the concrete pouring port 3 (e.g., Figure 3 As shown in the figure, the external pump pipe (not shown in the figure) is connected to the lower pipe opening of the concrete pouring pipe 5 by means of a buckle;

[0035] Step 3: Start the concrete pump and deliver the secondary lining concrete to the secondary lining concrete pouring area (the area between the initial support concrete 13 of the arch and the top formwork 1) through the concrete pouring pipe 5. Simultaneously, activate the attached vibrator 14 installed on the lower surface of the top formwork 1 for vibration. As the injected secondary lining concrete surface gradually rises, the gas in the secondary lining concrete pouring area is gradually discharged from the inclined pipe of the vent pipe 2. When the poured secondary lining concrete surface rises to the top arch surface, some concrete slurry enters the vent pipe 2 through the inclined pipe and flows out from the lower pipe opening. When the concrete slurry in the vent pipe 2 overflows, stop the secondary lining concrete pouring, seal the vent pipe 2 opening with the sealing plug 15, and close the concrete pouring port 3 by operating the movable cover plate 4 using the handle 9 (e.g., ...). Figure 4 (As shown), remove the external pump pipe;

[0036] Step 4: After the secondary lining concrete has solidified, open the movable buckle 10 and pull out the exhaust pipe 2, and grout at the original hole position until the gap between the secondary lining concrete pouring layer and the arch initial support concrete 13 is filled, and the grouting construction is completed.

Claims

1. A method for preventing voids and relieving pressure during the casting of the arch of a secondary steel formwork trolley, characterized in that: Grouting was performed using specialized equipment. The special device includes a vertically upward sealed exhaust pipe that penetrates the top formwork, with the upper opening of the exhaust pipe having an inclined opening structure; a concrete pouring port is provided on the top formwork, and a movable cover plate is provided at the concrete pouring port, the movable cover plate being slidably mounted on the surface of the top formwork; a concrete pouring pipe is fixed on the lower surface of the top formwork, located on one side of the exhaust pipe, with the upper opening of the concrete pouring pipe being fixedly connected to the concrete pouring port; a support plate and a positioning seat are fixed on the outer wall of the concrete pouring pipe, the support plate being provided with a drive mechanism for opening / closing the concrete pouring port, and the positioning seat being connected to the exhaust pipe located below the top formwork via a connector; A sealing plate is fitted onto the exhaust pipe located below the top mold plate via a sealing ring, and the upper surface of the sealing plate is in close contact with the lower surface of the top mold plate; the outer surface of the exhaust pipe is covered with plastic wrap. The grouting method includes the following steps: Step 1: After the top formwork is erected, the top of the inclined pipe opening of the exhaust pipe is brought into contact with the inner side of the initial support concrete of the arch. Then, the exhaust pipe under the top formwork is connected to the positioning seat through the connector. Step 2: Operate the drive mechanism to open the concrete pouring port, and connect the external pump pipe to the lower pipe opening of the concrete pouring pipe through the buckle; Step 3: Start the concrete delivery pump and transport the secondary lining concrete to the secondary lining concrete pouring area through the concrete pouring pipe. At the same time, start the vibrator attached to the underside of the top formwork for vibration. As the secondary lining concrete surface gradually rises, the gas in the secondary lining concrete pouring area is discharged from the inclined pipe of the exhaust pipe. When the secondary lining concrete surface rises to the top arch surface, some concrete slurry enters the exhaust pipe through the inclined pipe and flows out from the lower pipe opening. When the exhaust pipe is full of concrete slurry, stop the secondary lining concrete pouring, seal the lower opening of the exhaust pipe with a sealing plug, operate the drive mechanism to close the concrete pouring port, and remove the external pump pipe. Step 4: After the secondary lining concrete has solidified, open the connector, pull out the vent pipe, and grout at the original hole location until the gap between the secondary lining concrete pouring layer and the initial support concrete is filled.

2. The method for preventing voids and relieving pressure during the casting of the arch of the secondary lining steel formwork trolley as described in claim 1, characterized in that: The driving mechanism includes a rotating shaft hinged to the support plate. The rotating shaft passes vertically upward through the top mold plate and is fixedly connected to the movable cover plate. A handle is fixed to the lower end of the rotating shaft.

3. The method for preventing voids and relieving pressure during the casting of the arch of the secondary lining steel formwork trolley as described in claim 1 or 2, characterized in that: The connector is a movable buckle, and the positioning seat is connected to the exhaust pipe located below the top mold plate via the movable buckle.

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