Box girder core mold stripping method

Abstract

The application relates to a box girder core mould stripping method, characterized in that the box girder core mould is designed as a tubular structure capable of being inwardly folded, when stripping, the core mould is first inwardly folded to be separated from the inner surface of the box girder, and then the box girder core mould is pulled out of the box girder. The application aims to provide a box girder core mould stripping method with the core mould being pulled out and labor-saving, and solves the problem that the box girder core mould is labor-consuming when the box girder is prefabricated.

Description

Technical Field

[0001] This invention relates to the field of road and bridge construction technology, and in particular to a method for demolding the core mold of a box girder. Background Technology

[0002] During road construction, bridges are sometimes necessary. One construction method involves building piers and abutments, installing crossbeams on the piers, rapidly prefabricating box girders between the crossbeams, and then casting reinforced concrete onto the box girders. The box girder prefabrication process involves building a steel reinforcement cage inside the outer formwork of the box girder, placing the box girder core mold inside the steel reinforcement cage, pouring concrete, and after the concrete has solidified, removing the side and end formwork of the outer formwork of the box girder for curing. After curing, the core mold is then extracted. Current methods for demolding prefabricated box girders involve directly pulling out the box girder core mold while it is still bonded to the core, making extraction laborious. Summary of the Invention

[0003] The present invention aims to provide a labor-saving method for removing the core mold of a box girder, which solves the problem of laborious removal of the core mold during the prefabrication of box girders.

[0004] The above technical problems are solved by the following technical solution: a method for demolding a box girder core mold, characterized in that the box girder core mold is designed as a tubular structure that can retract inwards. During demolding, the core mold is first retracted inwards to separate from the inner surface of the box girder, and then the box girder core mold is pulled out of the box girder. First, the core mold retracts and detaches from the inner surface of the box girder, and then it is pulled out, making demolding less labor-intensive.

[0005] Preferably, the box girder core mold is formed by a core mold base plate, a core mold top plate, a core mold left side plate, and a core mold right side plate. The core mold base plate includes a left section and a right section, the core mold top plate includes a left section and a right section, the core mold left side plate includes an upper left section and a lower left section, and the core mold right side plate includes an upper right section and a lower right section. The left and right sections of the base plate are connected by several base plate hinges, and the right end face of the left section and the left end face of the right section abut against each other. The base plate hinges are located inside the box girder core mold, and the left and right sections of the top plate can be separated and joined together. The upper and lower sections of the left side plate are connected together by several left side plate hinges. The lower end face of the upper left side plate and the upper end face of the lower left side plate abut together. The left side plate hinges are located inside the box girder core mold. The upper and lower sections of the right side plate are connected together by several right side plate hinges. The lower end face of the upper right side plate and the upper end face of the lower right side plate abut together. The right side plate hinges are located inside the box girder core mold. The left section of the bottom plate is fixedly connected to the lower section of the left side plate. The upper section of the left side plate is fixedly connected to the left section of the top plate. The right section of the top plate is fixedly connected to the upper section of the right side plate. The lower section of the right side plate is fixedly connected to the right section of the bottom plate. The left and right lower sections of the mandrel are fixed together, connected by a lateral telescopic structure. This structure drives the left and right lower sections to rotate about the bottom plate hinge. The bottom and top plates of the mandrel are connected by a vertical telescopic structure, which drives the right top plate to rotate about the right side hinge and the left top plate to rotate about the left side hinge. When the mandrel retracts inward, the movement trajectories of the right and left top plates, the upper and lower left sides of the left and right sides of the bottom plates are all within the box girder. Within the space enclosed by the perimeter; during demolding: first, the vertical telescopic structure contracts, driving the right section of the top plate and the upper section of the right side plate to rotate towards the box girder core mold around the right side plate hinge, thus detaching from the inner surface of the box girder; then, the left section of the top plate and the upper section of the left side plate to rotate towards the box girder interior around the left side plate hinge, thus detaching from the inner surface of the box girder; next, while ensuring the bottom plate of the box girder can rotate, the horizontal telescopic structure contracts, causing the lower section of the left side plate and the left section of the bottom plate to rotate around the bottom plate hinge, thus detaching from the inner surface of the box girder; the lower section of the right side plate and the right section of the bottom plate to rotate around the bottom plate hinge, thus detaching from the inner surface of the box girder; finally, the box girder core mold is pulled out. This technical solution allows the core mold to detach from the box girder first, and then be pulled out, thus saving effort when removing the box girder core mold, and saving effort allows for the fabrication of longer box girders. The method to ensure the bottom template can rotate can be: first, lift the core mold bottom plate, the lower section of the left side plate, and the lower section of the right side plate upwards to a position where the bottom plate of the box girder can rotate and close.

[0006] Preferably, the vertical telescopic structure includes a left vertical cylinder and a right vertical cylinder. The cylinder body of the right vertical cylinder is hinged to the inner surface of the right section of the bottom plate via a right longitudinal lower hinge shaft, and the piston rod of the right vertical cylinder is hinged to the inner surface of the right section of the top plate via a right longitudinal upper hinge shaft. The cylinder body of the left vertical cylinder is hinged to the inner surface of the left section of the bottom plate via a left longitudinal lower hinge shaft, and the piston rod of the left vertical cylinder is hinged to the inner surface of the left section of the top plate via a left longitudinal upper hinge shaft. The lateral telescopic structure includes a lateral cylinder. The left end of the lateral cylinder is hinged to the inner surface of the lower section of the left side plate via a longitudinal left hinge shaft, and the right end is hinged to the inner surface of the lower section of the right side plate via a longitudinal right hinge shaft.

[0007] Preferably, the left end face of the right section of the roof slab and the right end face of the left section of the roof slab are fitted together. This allows for a more convenient and reliable sealing connection between the left and right ends of the roof slab, preventing grout leakage.

[0008] Preferably, a longitudinal groove is also included. Both the inner and outer surfaces of the longitudinal groove are arc surfaces. The centerline of the cylinder containing the inner surface of the longitudinal groove is the axis of the hinge of the base plate. The cylinder containing the inner surface of the longitudinal groove and the cylinder containing the outer surface of the longitudinal groove are coaxial. The left end of the longitudinal groove passes through the lower surface of the left section of the base plate, and the right end passes through the lower surface of the right section of the base plate. This technical solution ensures that the core mold base plate is directly positioned to allow it to rotate. That is, no lifting action is required; the lower left section of the left plate and the left section of the base plate can be driven to rotate around the hinge of the base plate to detach from the box girder, and the lower right section of the right plate and the right section of the base plate can be driven to rotate around the hinge of the base plate to detach from the box girder. This improves the convenience of demolding the box girder core mold.

[0009] Preferably, the left end face of the right section of the base plate and the right end face of the left section of the base plate are fitted together, with the left end face of the right section of the base plate pressing against the right end face of the left section of the base plate. At least one row of supporting balls is provided on the lower surface of the left section of the base plate, with the supporting balls in the same row distributed longitudinally and supported on the inner surface of the longitudinal groove. This design makes pulling out the box girder core mold easier. The longitudinal groove can be removed for reuse or retained on the box girder core mold. The method for removing the longitudinal groove is as follows: with both ends of the longitudinal groove extending beyond the box girder, after the box girder core mold is closed, lift both ends of the longitudinal groove to separate it from the adjacent core mold, then pull out the adjacent core mold, and then pull out the longitudinal groove. This method avoids breakage during the process of lifting the longitudinal groove to separate it from the box girder.

[0010] Preferably, the box girder outer formwork includes a bottom formwork plate, two side formwork plates detachably connected to the transverse ends of the bottom formwork, and two end formwork plates detachably connected to the longitudinal ends of the bottom formwork. When the box girder outer formwork is assembled, the end formwork plates are fitted onto the box girder core mold, and the end formwork plates are sealed against the end faces of the side formwork plates and the upper surfaces of the end formwork plates. A connecting lug is provided on the inner surface of the right section of the top plate, and a connecting lug is provided on the inner surface of the left section of the top plate. A connecting lug is provided on the inner surface of the upper section of the left side plate, and a connecting lug is provided on the inner surface of the lower section of the left side plate. The top plate has a connecting lug on the lower section of the left side plate, and a connecting lug on the inner surface of the upper section of the right side plate. The inner surface of the lower section of the right side plate also has a connecting lug. Several end plate fixing bolts pass through these connecting lugs and are threaded onto the connecting lugs on the right, left, upper, lower, and upper sections of the top plate, respectively, causing the end faces of the end plates on the same side to abut together. This facilitates fixing the end plates and the structure of the end plate fixing mechanism helps to fix the box girder core mold, preventing the box girder core mold from closing. It improves the ability to simultaneously fix end plates on the same side.

[0011] The beneficial effect of this invention is that it saves effort when pulling out adjacent core molds. Attached Figure Description

[0012] Figure 1 This is a side view schematic diagram of the mold for manufacturing the box girder according to the present invention;

[0013] Figure 2 for Figure 1 A magnified view of a portion of point A;

[0014] Figure 3 This is a schematic diagram showing the box girder core mold located inside the box girder.

[0015] Figure 4 for Figure 3 A magnified view of a portion of point G.

[0016] In the diagram: bottom formwork 1, side formwork 2, end formwork 3, bottom plate left section 60, bottom plate right section 61, top plate left section 62, top plate right section 63, left side plate upper section 64, left side plate lower section 65, right side plate upper section 66, right side plate lower section 67, bottom plate hinge 68, left side plate hinge 69, right side plate hinge 70, left vertical cylinder 71, right vertical cylinder 72, longitudinal slide 73, supporting ball 74, top plate right section connecting ear 75, top plate left section connecting ear 76, left side plate upper section connecting ear 77, left side plate lower section connecting ear 78, right side plate upper section connecting ear 79, right side plate lower section connecting ear 80, end formwork connecting ear 81, end formwork fixing bolt 82, box girder 120, box girder core mold 122. Detailed Implementation

[0017] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0018] See Figures 1 to 4A method for demolding a box girder core mold is disclosed. The mold for manufacturing the box girder includes an outer box girder mold and a core mold 122. The outer box girder mold includes a bottom template plate 1, two side templates 2 detachably connected to the transverse ends of the bottom template, and two end templates 3 detachably connected to the longitudinal ends of the bottom template. The bottom template plate, the two side templates, and the two end templates form the box girder cavity. The core mold is used to form the inner cavity of the box girder. When the outer box girder mold is assembled, the end templates are fitted onto the core mold, the end templates are sealed against the end faces of the side templates, and the end templates are sealed against the upper surface of the bottom template. The core mold is a tubular structure formed by a core mold bottom plate, a core mold top plate, a core mold left side plate, and a core mold right side plate. The core mold base plate includes a left section 60 and a right section 61; the core mold top plate includes a left section 62 and a right section 63; the core mold left side plate includes an upper left section 64 and a lower left section 65; and the core mold right side plate includes an upper right section 66 and a lower right section 67. The left and right sections of the base plate are connected by several base plate hinges 68. The left end face of the right section of the base plate and the right end face of the left section of the base plate are engaged and abutted together, with the left end face of the right section of the base plate pressing against the right end face of the left section of the base plate. The base plate hinges are located inside the box girder core mold. The left and right sections of the top plate can be separated and abutted together, with the right end face of the left section of the top plate and the left end face of the right section of the top plate engaged by an inclined surface, and the right end face of the left section of the top plate is located above the left end face of the right section of the top plate. The upper and lower sections of the left side plate are connected by several left side plate hinges 69. The lower end face of the upper left side plate and the upper end face of the lower left side plate abut together. The left side plate hinges are located inside the box girder core mold. The upper and lower sections of the right side plate are connected by several right side plate hinges 70. The lower end face of the upper right side plate and the upper end face of the lower right side plate abut together. The right side plate hinges are located inside the box girder core mold. The left section of the bottom plate is fixedly connected to the lower section of the left side plate. The upper left side plate is fixedly connected to the left section of the top plate. The right section of the top plate is fixedly connected to the upper right side plate. The lower right side plate is fixedly connected to the right section of the bottom plate. The lower sections of the left and right sides plate are connected by a lateral telescopic structure, which drives the lower sections of the left and right sides plate to rotate about the bottom plate hinge. The bottom plate and top plate are connected by a vertical telescopic structure. This structure drives the right section of the top plate to rotate around the right side plate hinge and the left section of the top plate to rotate around the left side plate hinge. When the box girder core mold retracts inward, the movement trajectories of the right and left sections of the top plate, the upper and lower sections of the left and right sides of the left and right sides of the bottom plate, as well as the left and right sections of the bottom plate, are all within the space enclosed by the inner circumference of the box girder. The vertical telescopic structure includes a left vertical cylinder 71 and a right vertical cylinder 72. The cylinder body of the right vertical cylinder is hinged to the inner surface of the right section of the bottom plate via a right longitudinal downward hinge shaft, and the piston rod of the right vertical cylinder is hinged to the inner surface of the right section of the top plate via a right longitudinal upward hinge shaft. Similarly, the cylinder body of the left vertical cylinder is hinged to the inner surface of the left section of the bottom plate via a left longitudinal downward hinge shaft, and the piston rod of the left vertical cylinder is hinged to the inner surface of the left section of the top plate via a left longitudinal upward hinge shaft.When closing the box girder core mold, the right vertical cylinder contracts first, followed by the left vertical cylinder. The lateral telescopic structure is a lateral cylinder, with its left end hinged to the inner surface of the lower section of the left side plate via a longitudinal left hinge shaft, and its right end hinged to the inner surface of the lower section of the right side plate via a longitudinal right hinge shaft. The box girder core mold also includes a longitudinal slide groove 73, the inner and outer surfaces of which are both arc surfaces. The centerline of the cylinder containing the inner surface of the longitudinal slide groove is the axis of the hinge of the bottom plate. The cylinder containing the inner surface of the longitudinal slide groove and the cylinder containing the outer surface of the longitudinal slide groove are coaxial. The left end of the longitudinal slide groove passes through the lower surface of the left section of the bottom plate, and the right end passes through the lower surface of the right section of the bottom plate. At least one row of support balls is provided on the lower surface of the left section of the bottom plate. The support balls 74 in the same row are distributed longitudinally and supported on the inner surface of the longitudinal slide groove. The inner surface of the right section of the top plate is provided with a connecting ear 75 for the right section of the top plate, the inner surface of the left section of the top plate is provided with a connecting ear 76 for the left section of the top plate, the inner surface of the upper section of the left side plate is provided with a connecting ear 77 for the upper section of the left side plate, the inner surface of the lower section of the left side plate is provided with a connecting ear 78 for the lower section of the left side plate, the inner surface of the upper section of the right side plate is provided with a connecting ear 79 for the upper section of the right side plate, and the inner surface of the lower section of the right side plate is provided with a connecting ear 80 for the lower section of the right side plate. The end template is provided with a number of end template connecting ears 81. A number of end template fixing bolts 82 pass through the end template connecting ears one by one and are threaded onto the connecting ears of the right section of the top plate, the connecting ears of the left section of the top plate, the connecting ears of the upper section of the left side plate, the connecting ears of the lower section of the left side plate, the connecting ears of the upper section of the right side plate, and the connecting ears of the lower section of the right side plate, so that the end faces of the end template and the side template abut together.

[0019] The demolding process for the box girder core mold is as follows: The right vertical cylinder retracts, driving the right end of the top plate to rotate inwards about the right side plate hinge, thus detaching the right section of the top plate and the upper section of the right side plate from the box girder; the left vertical cylinder retracts, driving the left end of the top plate to rotate inwards about the left side plate hinge, thus detaching the left section of the top plate and the upper section of the left side plate from the box girder; the transverse cylinder retracts, driving the lower sections of the left and right sides plate to rotate inwards about the bottom plate hinge, thus detaching the box girder core mold. The lower sections of the left side plate, the left section of the bottom plate, the lower section of the right side plate, and the right section of the bottom plate are all separated from the box girder; the transverse cylinder extends and resets, lifting the longitudinal slide rail to separate it from the box girder (this method avoids deformation and breakage of the longitudinal slide rail during lifting, preventing it from being separated and reused, because the longitudinal slide rail is still pressed down by the box girder core mold at three points along the transverse direction); the transverse cylinder retracts to a set length; the box girder core mold is pulled longitudinally to pull the adjacent core mold out of the box girder; the longitudinal slide rail is then pulled out.

Claims

1. A method for demolding the core mold of a box girder, characterized in that, The box girder core mold is designed as a tubular structure that can retract inwards. During demolding, the core mold is first retracted inwards to separate from the inner surface of the box girder, and then the box girder core mold is pulled out of the box girder. The box girder core mold is formed by a core mold bottom plate, a core mold top plate, a core mold left side plate, and a core mold right side plate. The core mold bottom plate includes a left section and a right section, the core mold top plate includes a left section and a right section, the core mold left side plate includes an upper section and a lower section, and the core mold right side plate includes an upper section and a lower section. The left and right sections of the bottom plate are connected together by several bottom plate hinges, and the right end face of the left section and the left end face of the right section abut against each other. Together, the bottom plate hinge is located inside the box girder core mold. The left and right sections of the top plate can be separated and abutted together. The upper and lower sections of the left side plate are connected together by several left side plate hinges. The lower end face of the upper section of the left side plate abuts with the upper end face of the lower section of the left side plate. The left side plate hinge is located inside the box girder core mold. The upper and lower sections of the right side plate are connected together by several right side plate hinges. The lower end face of the upper section of the right side plate abuts with the upper end face of the lower section of the right side plate. The right side plate hinge is located inside the box girder core mold. The left section of the bottom plate is fixedly connected to the lower section of the left side plate. The upper section of the left side plate is fixedly connected to the left section of the top plate. The right section of the top plate and... The upper section of the right side plate is fixed together, and the lower section of the right side plate is fixed together with the right section of the bottom plate. The lower sections of the left and right sides plate are connected by a lateral telescopic structure, which drives the lower sections of the left and right sides plate to rotate about the hinge of the bottom plate. The bottom plate and top plate of the mandrel are connected by a vertical telescopic structure, which drives the right section of the top plate to rotate about the hinge of the right side plate and the left section of the top plate to rotate about the hinge of the left side plate. When the box girder mandrel retracts inward, the right section of the top plate, the left section of the top plate, the upper section of the left side plate, the lower section of the left side plate, the upper section of the right side plate, the lower section of the right side plate, the left section of the bottom plate, and the right section of the bottom plate... The movement trajectory is all within the space enclosed by the inner circumference of the box girder. During demolding: first, the vertical telescopic structure contracts, driving the right section of the top plate and the upper section of the right side plate to rotate towards the box girder core mold around the right side plate hinge, thus separating from the inner surface of the box girder; then, the left section of the top plate and the upper section of the left side plate to rotate towards the box girder interior around the left side plate hinge, thus separating from the inner surface of the box girder; next, while ensuring that the core mold bottom plate can rotate, the horizontal telescopic structure contracts, causing the lower section of the left side plate and the left section of the bottom plate to rotate around the bottom plate hinge, thus separating from the inner surface of the box girder; the lower section of the right side plate and the right section of the bottom plate to rotate around the bottom plate hinge, thus separating from the inner surface of the box girder; finally, the box girder core mold is pulled out.

2. The method for demolding a box girder core mold according to claim 1, characterized in that, The vertical telescopic structure includes a left vertical cylinder and a right vertical cylinder. The cylinder body of the right vertical cylinder is hinged to the inner surface of the right section of the base plate via a right longitudinal lower hinge shaft, and the piston rod of the right vertical cylinder is hinged to the inner surface of the right section of the top plate via a right longitudinal upper hinge shaft. The cylinder body of the left vertical cylinder is hinged to the inner surface of the left section of the base plate via a left longitudinal lower hinge shaft, and the piston rod of the left vertical cylinder is hinged to the inner surface of the left section of the top plate via a left longitudinal upper hinge shaft. The lateral telescopic structure includes a lateral cylinder. The left end of the lateral cylinder is hinged to the inner surface of the lower section of the left side plate via a longitudinal left hinge shaft, and the right end is hinged to the inner surface of the lower section of the right side plate via a longitudinal right hinge shaft.

3. The method for demolding a box girder core mold according to claim 2, characterized in that, The left end face of the right section of the top plate and the right end face of the left section of the top plate are fitted together.

4. A method for demolding a box girder core mold according to claim 1, 2, 3, or 3, characterized in that, It also includes a longitudinal slide, the inner and outer surfaces of which are both arc surfaces. The center line of the cylinder on which the inner surface of the longitudinal slide is located is the axis of the hinge of the base plate. The cylinder on which the inner surface of the longitudinal slide is located and the cylinder on which the outer surface of the longitudinal slide are located are coaxial. The left end of the longitudinal slide passes through the lower surface of the left section of the base plate and the right end passes through the lower surface of the right section of the base plate.

5. A method for demolding a box girder core mold according to claim 4, characterized in that, The left end face of the right section of the base plate and the right end face of the left section of the base plate are engaged and abutted together. The left end face of the right section of the base plate presses on the right end face of the left section of the base plate. At least one row of support balls is provided on the lower surface of the left section of the base plate. The support balls in the same row of support balls are distributed longitudinally. The support balls are supported on the inner surface of the longitudinal groove.

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