A prefabricated concrete form for cast-in-situ pipe gallery side wall applied to narrow space and a construction method thereof

Abstract

A kind of application in narrow space cast-in-place pipe gallery side wall prefabricated concrete formwork and its construction method, corresponding left and right two cast-in-place pipe gallery side walls are provided with a group of prefabricated concrete formwork;Prefabricated concrete formwork includes outside fixed reinforcement, inside fixed reinforcement, multiple template units arranged in front and back along the length direction of cast-in-place pipe gallery;Template unit encloses the pouring space of cast-in-place pipe gallery side wall, and remains with cast-in-place pipe gallery side wall;Template unit includes two side plates, inside surrounding prefabricated concrete formwork located at inside and peripheral prefabricated concrete formwork located at outside, adjacent side plates are spliced by protruding part and recessed part;Inside fixed reinforcement is arranged between the inside bottom plate of cast-in-place pipe gallery side wall and inside surrounding prefabricated concrete formwork, outside fixed reinforcement is arranged between the outside steel sheet pile of cast-in-place pipe gallery side wall and peripheral prefabricated concrete formwork, to temporarily fix template unit, and is removed after pouring cast-in-place pipe gallery side wall.The present application can be operated in narrow space, improve construction efficiency, belong to the field of building construction technology.

Description

Technical Field

[0001] This invention relates to building construction technology, specifically to a precast concrete formwork for the side wall of a cast-in-place pipe gallery in a narrow space and its construction method. Background Technology

[0002] With the development of construction technology and the social economy, cast-in-place pipe galleries, as an application of urban underground structures, are being used more and more widely in the construction field, and the corresponding construction technology requirements are also becoming increasingly higher. In traditional construction processes, when using wooden formwork to enclose the pouring area of ​​the side walls of cast-in-place pipe galleries, the wooden formwork lacks sufficient strength and rigidity, and the manual control technology is highly demanding. When the support system is not erected properly, phenomena such as formwork bursting often occur, which often leads to honeycomb-like pitting or unevenness at the formwork joints after the side wall formwork of the cast-in-place pipe galleries is removed. This results in common quality problems such as poor waterproofing and appearance that do not meet the requirements for use.

[0003] Current construction techniques using wooden formwork require manual installation of tie rods, steel pipes, and timber on both the inner and outer sides of the cast-in-place pipe gallery sidewalls. This manual installation involves numerous components and can only begin after the reinforcement of the pipe gallery sidewalls is completed. This not only necessitates reserving sufficient working space on both sides of the pipe gallery but also impacts the efficiency of formwork installation and demolding. Furthermore, during urban foundation pit excavation, the presence of surrounding buildings and pipelines often prevents the provision of sufficient working space on the outer side of the cast-in-place pipe gallery.

[0004] The narrow space referred to in this invention refers to a space in urban construction where, due to the influence of surrounding buildings and pipelines, there is not enough working surface to be reserved on the outside of the cast-in-place pipe gallery. Generally, a space less than 50 centimeters can be considered a narrow space, in which case it is difficult for construction workers to enter. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the purpose of this invention is to provide a precast concrete formwork for the side walls of cast-in-place pipe gallery in narrow spaces and its construction method, which allows for operation in narrow spaces and improves construction efficiency. This solves the problem that in the prior art, due to the influence of surrounding buildings and pipelines during the excavation process, sufficient working space cannot be reserved on the outside of the cast-in-place pipe gallery, thus affecting the low efficiency of traditional wooden formwork installation and demolding in narrow spaces.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A precast concrete formwork for the side walls of a cast-in-place pipe gallery in a narrow space is provided, with a set of precast concrete formwork for each of the left and right side walls of the cast-in-place pipe gallery. Each set of precast concrete formwork includes outer fixing reinforcement, inner fixing reinforcement, and multiple formwork units arranged front to back along the length of the cast-in-place pipe gallery. The precast formwork units enclose the pouring space of the side wall of the cast-in-place pipe gallery and are retained with the side wall. Each formwork unit includes two side plates, namely an inner precast concrete formwork located on the inner side and an outer precast concrete formwork located on the outer side. In the front-back direction, one side of the side plate has a precast protrusion and the other side has a precast recess, so that adjacent side plates are joined together by the protrusion and the recess. The inner fixing reinforcement is set between the inner bottom plate of the side wall of the cast-in-place pipe gallery and the inner precast concrete formwork, and the outer fixing reinforcement is set between the outer steel sheet pile of the side wall of the cast-in-place pipe gallery and the outer precast concrete formwork to temporarily fix the formwork unit, and is removed after the side wall of the cast-in-place pipe gallery is poured.

[0008] As a preferred embodiment, the protruding part is located at the center of left and right on one side of the side plate, and is set along the entire height direction of the side plate. The cross-section of the protruding part is an isosceles trapezoid. The recessed part is located at the center of left and right on the other side of the side plate, and is set along the entire height direction of the side plate. The cross-section of the recessed part is an isosceles trapezoid.

[0009] As a preferred embodiment, two sponge strips are provided on one side of the side panel, with the sponge strips extending along the entire height of the side panel and located on the left and right sides of the protruding part; the sponge strips are bonded to one side of the side panel with epoxy resin adhesive.

[0010] As a preferred embodiment, multiple holes are provided in the side panel, and the multiple holes are arranged sequentially along the front-to-back direction, with each hole penetrating the side panel vertically.

[0011] As a preferred option, the outer precast concrete formwork measures 600mm in length, 50mm in width, and 3000mm in height; the inner precast concrete formwork measures 600mm in length, 50mm in width, and 2500mm in height; and 7 slots are reserved for each side panel. Holes.

[0012] As a preferred embodiment, the outer fixing reinforcement includes multiple bent bars; the bent bars include a straight section and a bent section with one end of the straight section bent into a hook shape; the other end of the straight section is welded to the steel sheet pile, and the connection between one end of the straight section and the bent section rests on the outer precast concrete formwork.

[0013] As a preferred option, each outer precast concrete formwork is provided with two rows of upper and lower bent bars; two upper and lower bent bars are provided in the same vertical direction, the height of the outer precast concrete formwork is h, the distance from the upper bent bar to the bottom of the outer precast concrete formwork is not less than 2h / 3, and the distance from the lower bent bar to the bottom of the outer precast concrete formwork is 1000mm; in the same row of bent bars, the spacing between adjacent bent bars is 250mm.

[0014] As a preferred embodiment, the inner fixed reinforcement includes multiple vertical reinforcements, multiple diagonal reinforcements, and multiple transverse reinforcements. The vertical reinforcements include a vertical section and a bent section at a 90-degree angle to the vertical section. The bent section is welded and fixed to the lower layer of reinforcement in the base slab, and the vertical section is attached to the side wall of the inner precast concrete formwork. The diagonal reinforcements include an inclined section and bent sections at both ends of the inclined section at a 135-degree angle to the inclined section. The lower bent section is welded and fixed to the lower layer of reinforcement in the base slab, and the upper bent section is welded and fixed to the vertical section of the vertical reinforcement. The transverse reinforcements spanning multiple vertical reinforcements are welded to the vertical sections, and two transverse reinforcements are provided for each vertical reinforcement.

[0015] A construction method for precast concrete formwork for cast-in-place pipe gallery sidewalls in narrow spaces involves precasting formwork units in a factory and transporting them to the construction site. The formwork units form the pouring area for the cast-in-place pipe gallery sidewalls in the narrow space. The formwork units are spliced ​​together using protruding and recessed parts. The inner precast concrete formwork is temporarily fixed by inner fixing steel bars, and the outer precast concrete formwork is temporarily fixed by outer fixing steel bars. After pouring, the outer and inner fixing steel bars are removed, and the formwork units do not need to be dismantled.

[0016] As a preferred option, before splicing the template units, on the side panel with protrusions, the sponge strip is bonded and fixed along the height line using epoxy resin adhesive to ensure that the joints between adjacent side panels are tight and leak-proof; adjacent template units are connected using a dry joint method.

[0017] The principle of this invention is:

[0018] For cast-in-place pipe gallery side walls in narrow spaces, formwork units are used to form the pouring area. The two side plates of the formwork unit are pre-processed with protruding and recessed parts. The formwork units are processed according to uniform specifications and dimensions. During the assembly of adjacent side plates, the side plate with the protruding part is bonded with a sponge strip using epoxy resin adhesive. Adjacent side plates are connected by a dry joint method through the protruding and recessed parts. The steel sheet piles on the outer side of the side wall are welded with bent bars as temporary fixing devices for the outer precast concrete formwork. Vertical and diagonal steel bars are reserved on the bottom plate on the inner side of the side wall. Horizontal steel bars are set on the vertical steel bars to fix the inner precast concrete formwork, ensuring the integrity and stability of the formwork unit splicing. The pouring area formed within the formwork unit effectively improves the efficiency of formwork installation and demolding in narrow spaces, and increases the strength and rigidity of the formwork installation.

[0019] The present invention has the following advantages:

[0020] 1. Design spliced ​​formwork units, with the pouring area forming the side wall within each unit, allowing operation even in narrow spaces.

[0021] 2. Using prefabricated template units, which are prefabricated in the factory, greatly improves construction efficiency and reduces construction difficulty.

[0022] 3. Using concrete formwork units, the formwork units are integrated with the side walls after the side walls are poured, eliminating the need for formwork removal and improving work efficiency.

[0023] 4. To cope with narrow spaces, a simple bent-rib structure is adopted, which not only ensures the stability of the formwork unit and prevents it from shifting under external forces and its own weight, but also facilitates assembly and disassembly and construction.

[0024] 5. The internal fixed reinforcement structure composed of vertical, diagonal, and horizontal reinforcement not only ensures the stability of the formwork unit and prevents displacement under external forces and its own weight, but also facilitates assembly and disassembly, and makes construction easier.

[0025] 6. The splicing structure uses a combination of raised and recessed parts, and sponge strips are preferred to ensure that the joints are tight and leak-proof.

[0026] 7. Multiple holes are provided in the side panels to reduce the amount of concrete used in the formwork. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of precast concrete formwork applied to the side walls of cast-in-place pipe gallery in narrow spaces.

[0028] Figure 2 This is a magnified view of a portion of the precast concrete formwork used for the side walls of cast-in-place pipe gallery in narrow spaces.

[0029] Figure 3 It is a 3D view of the inner precast concrete formwork.

[0030] Figure 4 It is a 3D diagram of a bent bar.

[0031] Figure 5 It is a 3D diagram of the vertical reinforcing bars.

[0032] Figure 6 It is a 3D diagram of the inclined reinforcing bars.

[0033] Figure 7 It is a 3D diagram of the horizontal reinforcing bars.

[0034] Among them, 1 is the inner precast concrete formwork, 2 is the outer precast concrete formwork, 3-1 is the protruding part, 3-2 is the recessed part, 4 is the sponge strip, 5 is the bent bar, 6 is the vertical bar, 7 is the diagonal bar, 8 is the horizontal bar, and 9 is the steel sheet pile. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to specific embodiments.

[0036] A precast concrete formwork for the side walls of a cast-in-place pipe gallery in a narrow space is provided, with a set of precast concrete formwork for each of the left and right side walls of the cast-in-place pipe gallery. Each set of precast concrete formwork includes outer fixing reinforcement, inner fixing reinforcement, and multiple formwork units arranged front to back along the length of the cast-in-place pipe gallery. The precast formwork units enclose the pouring space of the side wall of the cast-in-place pipe gallery and are retained with the side wall. Each formwork unit includes two side plates, namely an inner precast concrete formwork located on the inner side and an outer precast concrete formwork located on the outer side. In the front-back direction, one side of the side plate has a precast protrusion and the other side has a precast recess, so that adjacent side plates are joined together by the protrusion and the recess. The inner fixing reinforcement is set between the inner bottom plate of the side wall of the cast-in-place pipe gallery and the inner precast concrete formwork, and the outer fixing reinforcement is set between the outer steel sheet pile of the side wall of the cast-in-place pipe gallery and the outer precast concrete formwork to temporarily fix the formwork unit, and is removed after the side wall of the cast-in-place pipe gallery is poured.

[0037] The protruding part is located at the center of left and right on one side of the side panel, and is set along the entire height direction of the side panel. The cross-section of the protruding part is an isosceles trapezoid. The recessed part is located at the center of left and right on the other side of the side panel, and is set along the entire height direction of the side panel. The cross-section of the recessed part is an isosceles trapezoid.

[0038] Two sponge strips are installed on one side of the side panel, and the sponge strips are installed along the entire height of the side panel. The two sponge strips are located on the left and right sides of the protruding part; the sponge strips are glued to one side of the side panel with epoxy resin adhesive.

[0039] Multiple holes are provided inside the side panel, and the holes are arranged sequentially along the front-to-back direction. Each hole penetrates the side panel from top to bottom.

[0040] The outer precast concrete formwork measures 600mm in length, 50mm in width, and 3000mm in height; the inner precast concrete formwork measures 600mm in length, 50mm in width, and 2500mm in height; 7 slots are reserved for each side panel. Holes.

[0041] The outer fixing reinforcement includes multiple bent bars; each bent bar consists of a straight section and a bent section with one end of the straight section bent into a hook shape; the other end of the straight section is welded to the sheet pile, and the connection between the straight section and the bent section rests against the outer precast concrete formwork. The bent bars are made of HRB400 steel bars with a diameter of 12mm. The length of the straight section is the distance from the sheet pile to the outer precast concrete formwork, the bending angle is 135°, forming the bent section, and the hook increases the length by 5d, where d is the diameter of the bent bar.

[0042] Each outer precast concrete formwork is equipped with two rows of upper and lower bent bars; two upper and lower bent bars are set in the same vertical direction. The height of the outer precast concrete formwork is h. The distance from the upper bent bar to the bottom of the outer precast concrete formwork is not less than 2h / 3. The distance from the lower bent bar to the bottom of the outer precast concrete formwork is 1000mm. In the same row of bent bars, the spacing between adjacent bent bars is 250mm.

[0043] The inner fixed reinforcement includes multiple vertical reinforcement bars, multiple diagonal reinforcement bars, and multiple transverse reinforcement bars. The vertical reinforcement bars include a vertical section and a bent section at a 90-degree angle to the vertical section. The bent section is welded and fixed to the lower layer of reinforcement bars in the base slab, and the vertical section is attached to the side wall of the inner precast concrete formwork. The diagonal reinforcement bars include an inclined section and a bent section at both ends of the inclined section at a 135-degree angle to the inclined section. The lower bent section is welded and fixed to the lower layer of reinforcement bars in the base slab, and the upper bent section is welded and fixed to the vertical section of the vertical reinforcement bars. The transverse reinforcement bars that span multiple vertical reinforcement bars are welded to the vertical sections, and two transverse reinforcement bars are set for each vertical reinforcement bar.

[0044] Vertical reinforcement: Reserved during the binding process of the bottom slab reinforcement. @500mm vertical reinforcement, one end of the vertical reinforcement is processed into a 10d bend with a bending angle of 90°. The bend is fixed to the bottom layer reinforcement of the base plate by single-sided welding. The exposed vertical section of the vertical reinforcement is 2500mm long, where d is the diameter of the vertical reinforcement.

[0045] Diagonal reinforcement: During the binding process of the bottom slab reinforcement, φ22mm@500mm diagonal reinforcement is reserved. The two ends of the diagonal reinforcement are processed into 10d bends with a bending angle of 135°. One end of the bend is fixed to the bottom layer reinforcement of the bottom slab by single-sided welding, and the other end is fixed to the exposed vertical reinforcement by single-sided welding to ensure that the vertical reinforcement does not shift. Here, d is the diameter of the diagonal reinforcement.

[0046] Horizontal reinforcement: Two layers of φ22mm horizontal reinforcement are set along the front and back direction. The distance between the upper horizontal reinforcement and the bottom of the inner precast concrete formwork is not less than 2 / 3 of the height. The lower horizontal reinforcement is set 1000mm from the bottom of the inner precast concrete formwork.

[0047] A construction method for precast concrete formwork for cast-in-place pipe gallery sidewalls in narrow spaces involves precasting formwork units in a factory and transporting them to the construction site. The formwork units form the pouring area for the cast-in-place pipe gallery sidewalls in the narrow space. The formwork units are spliced ​​together using protruding and recessed parts. The inner precast concrete formwork is temporarily fixed by inner fixing steel bars, and the outer precast concrete formwork is temporarily fixed by outer fixing steel bars. After pouring, the outer and inner fixing steel bars are removed, and the formwork units do not need to be dismantled.

[0048] Before splicing the template units, on the side panel with protrusions, use epoxy resin adhesive to bond and fix the sponge strip along the height line to ensure that the joints of adjacent side panels are tight and leak-proof; adjacent template units are connected by dry jointing.

[0049] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A precast concrete formwork for the side walls of cast-in-place pipe gallery in narrow spaces, characterized in that: A set of precast concrete formwork is set for each of the left and right side walls of the cast-in-place pipe gallery. Each set of precast concrete formwork includes outer fixing reinforcement, inner fixing reinforcement, and multiple formwork units arranged back and forth along the length of the cast-in-place pipe gallery. The precast formwork units enclose the pouring space of the cast-in-place pipe gallery side wall and are retained with the cast-in-place pipe gallery side wall. Each formwork unit includes two side plates, namely the inner precast concrete formwork located on the inner side and the outer precast concrete formwork located on the outer side. In the front-back direction, one side of the side plate has a precast protrusion and the other side has a precast recess, so that adjacent side plates are joined together by the protrusion and the recess. The inner fixing reinforcement is set between the inner bottom plate of the cast-in-place pipe gallery side wall and the inner precast concrete formwork, and the outer fixing reinforcement is set between the outer steel sheet pile of the cast-in-place pipe gallery side wall and the outer precast concrete formwork to temporarily fix the formwork unit and is removed after the cast-in-place pipe gallery side wall is poured. The outer fixing reinforcement includes multiple bent bars; the bent bars include a straight section and a bent section with one end of the straight section bent into a hook shape; the other end of the straight section is welded to the steel sheet pile, and the connection between the straight section and the bent section rests on the outer precast concrete formwork. The inner fixed reinforcement includes multiple vertical bars, multiple diagonal bars, and multiple transverse bars. The vertical bars include a vertical section and a bent section at a 90-degree angle to the vertical section. The bent section is welded and fixed to the lower layer of reinforcement in the base slab, and the vertical section is attached to the side wall of the inner precast concrete formwork. The diagonal bars include an inclined section and bent sections at both ends of the inclined section at a 135-degree angle to the inclined section. The lower bent section is welded and fixed to the lower layer of reinforcement in the base slab, and the upper bent section is welded and fixed to the vertical section of the vertical bars. The transverse bars that span multiple vertical bars are welded to the vertical sections, and two transverse bars are set for each vertical bar. The narrow space refers to the fact that there is not enough working surface to be reserved on the outside of the cast-in-place pipe gallery, which is less than 50 cm.

2. A precast concrete formwork for the side wall of a cast-in-place pipe gallery in a narrow space, as described in claim 1, is characterized in that: The protruding part is located at the center of left and right on one side of the side panel, and is set along the entire height direction of the side panel. The cross-section of the protruding part is an isosceles trapezoid. The recessed part is located at the center of left and right on the other side of the side panel, and is set along the entire height direction of the side panel. The cross-section of the recessed part is an isosceles trapezoid.

3. A precast concrete formwork for the side wall of a cast-in-place pipe gallery in a narrow space, as described in claim 2, is characterized in that: Two sponge strips are installed on one side of the side panel, and the sponge strips are installed along the entire height of the side panel. The two sponge strips are located on the left and right sides of the protruding part; the sponge strips are glued to one side of the side panel with epoxy resin adhesive.

4. A precast concrete formwork for the side wall of a cast-in-place pipe gallery in a narrow space, as described in claim 1, is characterized in that: Multiple holes are provided inside the side panel, and the holes are arranged sequentially along the front-to-back direction. Each hole penetrates the side panel from top to bottom.

5. A precast concrete formwork for the side wall of a cast-in-place pipe gallery in a narrow space, as described in claim 4, is characterized in that: The outer precast concrete formwork measures 600mm in length, 50mm in width, and 3000mm in height; the inner precast concrete formwork measures 600mm in length, 50mm in width, and 2500mm in height; each side panel has 7 φ40mm holes.

6. A precast concrete formwork for the side wall of a cast-in-place pipe gallery in a narrow space, as described in claim 1, is characterized in that: Each outer precast concrete formwork is equipped with two rows of upper and lower bent bars; two upper and lower bent bars are set in the same vertical direction. The height of the outer precast concrete formwork is h. The distance from the upper bent bar to the bottom of the outer precast concrete formwork is not less than 2h / 3. The distance from the lower bent bar to the bottom of the outer precast concrete formwork is 1000mm. In the same row of bent bars, the spacing between adjacent bent bars is 250mm.

7. A construction method for precast concrete formwork for the side walls of cast-in-place pipe gallery in narrow spaces, according to any one of claims 1 to 6, characterized in that: Prefabricated formwork units are manufactured in the factory and transported to the construction site. For the side walls of the cast-in-place pipe gallery in narrow spaces, formwork units are used to form the pouring area. The formwork units are spliced ​​together by protruding and recessed parts. The inner prefabricated concrete formwork is temporarily fixed by the inner fixing steel bars, and the outer prefabricated concrete formwork is temporarily fixed by the outer fixing steel bars. After pouring, the outer fixing steel bars and the inner fixing steel bars are removed, and the formwork units do not need to be removed.

8. A construction method for precast concrete formwork for the side walls of a cast-in-place pipe gallery in a narrow space, as described in claim 7, characterized in that: Before splicing the template units, on the side panel with protrusions, use epoxy resin adhesive to bond and fix the sponge strip along the height line to ensure that the joints of adjacent side panels are tight and leak-proof; adjacent template units are connected by dry jointing.

Images