A method for constructing a thin-walled hollow pier

Abstract

The application discloses a construction method of a thin-wall hollow bridge pier and belongs to the technical field of bridge construction. The method constructs the thin-wall hollow bridge pier through processes such as erecting an outer mold, erecting an inner mold and pouring the bridge pier. The outer mold is fixed by being embraced by a diagonal pull rod, and the fixing is realized without the inner support rod in the traditional process. The inner mold is connected with two inner mold frame sections through the middle section of the inner mold, and the inner mold is quickly disassembled in cooperation with the inner support rod.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and more specifically to a method for constructing thin-walled hollow bridge piers. Background Technology

[0002] Among existing technologies, prefabricated bridge structures offer significant socio-economic benefits due to their ability to accelerate construction, reduce environmental and traffic impacts, and minimize hazardous operations.

[0003] In practical applications, prefabricated bridge structures are subject to limitations in on-site hoisting equipment and transportation capacity, making it imperative to use lightweight prefabricated piers to expand the application scope of prefabricated piers.

[0004] Using hollow precast piers can reduce the weight of precast structures and has good application prospects. The connection between hollow precast piers and the abutment or cap beam structure can adopt the conventional reinforcement arrangement, with longitudinal reinforcement arranged both inside and outside. The longitudinal reinforcement of the column and the longitudinal reinforcement between the abutment and cap beam are all connected by grouting sleeves.

[0005] However, during the bridge construction process, the difficulty in disassembling and assembling the inner and outer formwork, and the inability to reuse them, greatly reduced construction efficiency, were also detrimental to environmental protection, and brought many inconveniences to the construction process. Summary of the Invention

[0006] To address the shortcomings of the aforementioned technical solutions, the present invention aims to provide a method for constructing thin-walled hollow bridge piers.

[0007] The objective of this invention is achieved through the following technical solution.

[0008] A method for constructing a thin-walled hollow bridge pier includes the following steps:

[0009] Step 1: Construct the first set of outer formwork and install trusses on its outer side, then pour the solid section at the bottom of the pier; each set of outer formwork is divided into three layers of sub-outer formwork from bottom to top, and each layer of sub-outer formwork includes four sub-outer formwork connected end to end by diagonal tie rods.

[0010] Step 2: Hoist the first set of inner templates to the top of the bottom solid section. The first set of inner templates is divided into one layer of first variable diameter inner template and two layers of equal diameter inner templates from bottom to top. The first variable diameter inner template and each layer of equal diameter inner template includes two inner template frame segments and a wedge-shaped inner template middle section set between the two inner template frame segments.

[0011] Step 3: Cast the first hollow pier between the first set of outer formwork and the first set of inner formwork. After solidification, remove the two layers of sub-outer formwork at the bottom of the first set of outer formwork, as well as the first layer of variable-diameter sub-inner formwork and the first layer of equal-diameter sub-inner formwork at the bottom of the first set of inner formwork. Then, lift the two removed layers of outer formwork upwards and build them on the remaining layer of outer formwork to form the second set of outer formwork. The bottom of the second set of outer formwork is supported by a base support. Then, lift the removed layer of equal-diameter sub-inner formwork upwards and build it on the remaining layer of equal-diameter sub-inner formwork. Then, build another layer of equal-diameter sub-inner formwork to form the second set of inner formwork. The bottom of the second set of inner formwork is supported by a base support.

[0012] Step 4: Cast the second hollow pier between the second set of outer formwork and the second set of inner formwork. After solidification, continue to build and cast the pier upwards in sequence as in Step 3 until the hollow pier reaches the casting height, and then cover it with the pier cap beam.

[0013] In the above technical solution, in step 4, when building the third set of inner templates up to the penultimate set of inner templates, the two equal-diameter sub-inner templates located at the bottom of the previous set of inner templates are flipped upwards. When building the last set of inner templates, only one equal-diameter sub-inner template needs to be flipped upwards, and the second variable-diameter sub-inner template is built on the equal-diameter sub-inner template. The diameter of the second variable-diameter sub-inner template gradually decreases from bottom to top.

[0014] In the above technical solution, during the pouring of each hollow pier section, multiple base supports are pre-embedded horizontally at intervals on the outer and inner sides of each hollow pier section, and the base supports support the remaining outer formwork or equal-diameter inner formwork.

[0015] In the above technical solution, each truss includes two oppositely arranged polygonal truss segments and two oppositely arranged straight truss segments. The two polygonal truss segments and the two straight truss segments enclose a hexagonal truss, which is arranged around the upper part of each sub-sub-formwork.

[0016] In the above technical solution, a ladder opening is provided on the outer side of the connection between the broken truss segment and the straight truss segment, and a straight ladder is slidably installed between the ladder openings of two adjacent trusses for workers to go up and down.

[0017] In the above technical solution, each set of outer templates has vertical ribs installed on its outer side and back bars installed horizontally.

[0018] In the above technical solution, the four connected sub-outer templates are a first sub-outer template arranged symmetrically front to back and a second sub-outer template arranged symmetrically left to right. The second sub-outer template includes a straight connecting part and a bend at both ends of the straight connecting part. A first diagonal tie rod mounting seat is welded to the outer side of each end of the straight connecting part near the bend. A second diagonal tie rod mounting seat is installed on the outer side of each end of the first sub-outer template. Diagonal tie rods are installed on adjacent first and second diagonal tie rod mounting seats.

[0019] In the above technical solution, the outer template is connected to the truss through a plurality of spaced telescopic limiting connectors. The limiting connectors include connecting hooks and pads. The hook end of the connecting hook is hooked onto the outer template, and the other end is provided with external threads. The truss is limited by nuts and pads.

[0020] In the above technical solution, the middle section of the inner template is slidably installed between the ends of the two inner template frame sections, and the two inner template middle sections are connected by a transverse inner support rod. Multiple transverse inner support rods are arranged in parallel inside each inner template frame section.

[0021] In the above technical solution, each inner template frame segment includes two rotatably connected “7”-shaped templates; when installing the inner template, the two “7”-shaped templates are brought together by adjusting the transverse inner support rod to form the inner template frame segment.

[0022] The advantages and beneficial effects of this invention are as follows:

[0023] 1. This invention achieves enclosure and fixation of the outer template through trusses and diagonal braces, eliminating the need for internal support rods in traditional processes;

[0024] 2. The inner template of the present invention includes a detachable middle section of the inner template. By quickly assembling and disassembling the middle section of the inner template, and in conjunction with the transverse inner support rod, the quick assembly and disassembly of the inner template can be achieved.

[0025] 3. This invention achieves template reuse and improves resource utilization by flipping the outer and inner templates upward. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating steps 1-2 of the construction method of the present invention.

[0027] Figure 2 This is a flowchart illustrating step 3 of the construction method of the present invention.

[0028] Figure 3 This is a flowchart illustrating step 4 of the construction method of the present invention.

[0029] Figure 4This is a top view of the overall structure of the thin-walled hollow bridge pier of the present invention (with the pier cap beam removed).

[0030] Figure 5 This is a partial structural schematic diagram of the outer template of the present invention.

[0031] Figure 6 This is a top view of the inner template of the present invention.

[0032] Figure 7 for Figure 4 A magnified view of a portion at point A.

[0033] Figure 8 for Figure 5 A magnified view of a portion of point B.

[0034] Figure 9 This is a schematic diagram of the inner template structure of the first variable diameter sub-sub ...

[0035] Figure 10 This is a magnified view of a portion of the base.

[0036] Wherein, 1: First group of outer formwork, 1.1: Sub-outer formwork, 1.11: Second sub-outer formwork, 1.111: Straight connection section, 1.112: Corner section, 1.12: First sub-outer formwork, 1.2: Transition formwork, 1.3: First diagonal tie rod mounting base, 1.4: Second diagonal tie rod mounting base, 2: Truss, 2.1: Broken line honed segment, 2.2: Straight honed segment, 3: First group of inner formwork, 3.1: First variable diameter sub-inner formwork, 3.11: Upper equal diameter section, 3.12: Lower variable diameter section, 3.2: Equal diameter sub-inner formwork, 4: Second group of outer formwork. 5: Second set of inner formwork, 6: Solid section at the bottom of the pier, 7: Second variable diameter inner formwork, 8: Pier cap beam, 9: First hollow pier section, 10: Ladder opening, 11: Horizontal inner strut, 12: Diagonal tie rod, 13: Platform column, 14: Platform support, 15: Back brace, 16: Inner formwork frame section, 16.1: "7" shaped formwork, 17: Middle section of inner formwork, 18: Pad plate, 19: Limiting connector, 19.1: Connecting hook, 19.2: Pad block, 20: Second hollow pier section, 21: Reinforcing rib, 22: Frustum-shaped nut, 23: Bottom support rod. Detailed Implementation

[0037] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0038] Example 1

[0039] like Figures 1-4 As shown, a method for constructing a thin-walled hollow bridge pier includes the following steps:

[0040] like Figure 1As shown, in step 1, the first set of outer templates 1 is erected and the truss 2 is installed on the outside of the first set of outer templates. Then, the solid section 6 at the bottom of the pier is poured. The truss 2 serves as an operating platform for workers. Each set of outer templates 1 is divided into three layers of sub-outer templates 1.1 from bottom to top. The upper part of each layer of sub-outer templates 1.1 is surrounded by a truss 2. Each layer of sub-outer templates 1.1 includes four sub-outer templates connected end to end by a tie rod 12.

[0041] Step 2: Hoist the first set of inner templates 3 onto the top of the solid section 6 at the bottom of the pier. The first set of inner templates 3, from bottom to top, includes one layer of first variable-diameter inner template 3.1 and two layers of equal-diameter inner templates 3.2. The first variable-diameter inner template 3.1 and each layer of equal-diameter inner template 3.2 include two inner template frame segments 16 and a wedge-shaped inner template middle section 17 set between the two inner template frame segments. The first variable-diameter inner template 3.1 is divided into an upper equal-diameter section 3.11 and a lower variable-diameter section 3.12. The diameter of the lower variable-diameter section 3.12 gradually increases from bottom to top, while the diameter of the upper equal-diameter section 3.11 remains unchanged (e.g., ...). Figure 9 (As shown). Preferably, a transition template 1.2 is overlapped between the first layer of sub-outer template 1.1 and the second layer of sub-outer template 1.1 from bottom to top in the first group of outer templates 1, so that the height of the solid section 6 at the bottom of the pier plus the height of the first variable diameter inner template 3.1 is equal to the height of the transition template 1.2 plus the height of one layer of sub-outer template 1.1.

[0042] Step 3: After the first set of inner formwork 3 is hoisted, the first hollow pier 9 is poured between the first set of outer formwork 1 and the first set of inner formwork 3, i.e., at the top of the solid section 6 at the bottom of the pier. When the strength of the solid section 6 at the bottom of the pier and the first hollow pier 9 reaches the construction requirements, the two layers of sub-outer formwork 1.1 at the bottom of the first set of outer formwork 1, and the first layer of first variable diameter sub-inner formwork 3.1 and the first layer of equal diameter sub-inner formwork 3.2 at the bottom of the first set of inner formwork 3 are removed. The two layers of sub-outer formwork 1.1 that have been removed are then lifted up and erected on the remaining layer of sub-outer formwork 1.1 to form the second set of outer formwork 4. The bottom of the second set of outer formwork 4 is supported by a base support. The removed layer of equal diameter sub-inner formwork 3.2 is then lifted up and erected on the remaining layer of equal diameter sub-inner formwork 3.2. Then another layer of equal diameter sub-inner formwork 3.2 is erected to form the second set of inner formwork 5. The bottom of the second set of inner formwork 5 is supported by a base support.

[0043] like Figures 2-3As shown, in step 4, the second hollow pier 20 is poured between the second set of outer formwork 4 and the second set of inner formwork 5. When the poured pier reaches the construction strength, the third set of outer formwork and the third set of inner formwork are raised upwards according to the process in step 3 (when building the third set of inner formwork, the two layers of equal-diameter inner formwork 3.2 located at the bottom of the second set of inner formwork 5 are raised upwards). The upward raising and pouring continues until the hollow pier reaches the pouring height and the pier cap beam 8 is placed on top. At the same time, preferably, when building the last set of inner formwork, only one layer of equal-diameter inner formwork 3.2 needs to be raised upwards. The second variable-diameter inner formwork 7 is built on the equal-diameter inner formwork 3.2, and the diameter of the second variable-diameter inner formwork 7 gradually decreases from bottom to top.

[0044] Regarding the base:

[0045] like Figure 10 As shown, further, during the casting of hollow bridge piers, multiple base supports are pre-embedded laterally at intervals on the inner and outer sides of each hollow bridge pier section. The base supports on the outer side support a layer of sub-outer template 1.1, and the base supports on the inner side support a layer of equal-diameter sub-inner template 3.2. Preferably, the base supports include a frustum-shaped nut 22 and a base support rod 23. The front part of the base support rod 23 is threaded, and the lateral diameter of the base support rod 23 gradually increases. The front part is screwed into the frustum-shaped nut 22 pre-embedded in the hollow bridge pier, and the rear part is used to support the layer of sub-outer template 1.1 or equal-diameter sub-inner template 3.2.

[0046] For truss 2:

[0047] like Figure 4 As shown, each of the trusses 2 further includes two oppositely arranged zigzag segments 2.1 and two oppositely arranged straight zigzag segments 2.2. The two zigzag segments 2.1 and the two straight zigzag segments 2.2 enclose a hexagonal truss 2, which is arranged around the outer template. A ladder opening 10 is provided on the outside of the connection between the zigzag segment 2.1 and the straight zigzag segment 2.2. A straight ladder is slidably installed between the ladder openings 10 of two adjacent trusses 2 for workers to go up and down.

[0048] like Figure 3 As shown, preferably, platform columns 13 are installed on the outer edge of the truss 2 to ensure construction safety. The bottom of the truss 2 is connected to the outer formwork through a platform bracket 14, which provides support for the truss 2.

[0049] For external templates:

[0050] Each set of outer templates has vertical ribs installed on the outside and horizontal back bars 15 installed to strengthen the outer template and prevent deformation.

[0051] like Figure 5 , Figures 7-8 As shown, furthermore, the cross-section of each set of outer templates is hexagonal. The four sub-outer templates include two second sub-outer templates 1.11 arranged symmetrically from left to right and two first sub-outer templates 1.12 arranged symmetrically from front to back. The two second sub-outer templates 1.11 and the first sub-outer templates 1.12 are connected end to end to form a sub-outer template 1.1 with a hexagonal cross-section. Each second sub-outer template 1.11 includes a straight connecting part 1.111 and bends 1.112 at both ends of the straight connecting part 1.111. A first diagonal brace mounting seat 1.3 is welded to the outer sides of both ends of the connecting part 1.111 near the bend 1.112. A second diagonal brace mounting seat 1.4 is installed on the outer sides of both ends of the first sub-outer formwork 1.12. Diagonal braces 12 are threaded through the adjacent first diagonal brace mounting seats 1.3 and second diagonal brace mounting seats 1.4. The diagonal braces 12 are locked by clamping components, thereby clamping the adjacent second sub-outer formwork 1.11 and first sub-outer formwork 1.12 tightly. The outer formwork is tightly secured by the four diagonal braces 12. When disassembling each layer of sub-outer formwork 1.1, it is only necessary to first remove the truss 2 on the outside of the sub-outer formwork 1.1 and remove the four diagonal braces 12. This allows each layer of sub-outer formwork 1.1 to be separated into two second sub-outer formwork 1.11 and two first sub-outer formwork 1.12, achieving quick assembly and disassembly of the outer formwork.

[0052] Preferably, the first tie rod mounting base 1.3 and the second tie rod mounting base 1.4 are both mounted on the corresponding parts (outside the bend 1.112 or outside the first sub-outer template 1.12) by a pad 18.

[0053] Preferably, the outer template is connected to the truss 2 via multiple spaced retractable limiting connectors 19. Each limiting connector 19 includes a connecting hook 19.1 and a pad 19.2. The hook end of the connecting hook 19.1 is hooked onto the outer template, and the other end is provided with an external thread. The nut and the pad 19.2 limit it to the truss 2, thereby achieving a fixed connection between the truss 2 and the outer template. When dismantling the connection between the truss 2 and the outer template, it is only necessary to unscrew the nut and remove the pad 19.2 to disconnect the connection between the truss 2 and the outer template. The connecting hook 19.1 remains on the outer template to await the next installation of the outer template.

[0054] For internal templates:

[0055] like Figure 4 and Figure 6 As shown, furthermore, the cross-section of each set of inner templates is hexagonal.

[0056] Furthermore, each layer of sub-inner template (including equal-diameter sub-inner template 3.2, first variable-diameter sub-inner template 3.1, and second variable-diameter sub-inner template 7) has a hexagonal cross-section and is formed by two detachably connected inner template frame segments 16. The two ends of one inner template frame segment 16 are respectively connected to the two ends of the other inner template frame segment 16 through an inner template middle section 17. Each inner template middle section 17 is slidably installed between the ends of the two inner template frame segments 16. The two inner template middle sections 17 are connected by a transverse inner support rod 11 (the two ends of the transverse inner support rod 11 are respectively hinged to an inner template middle section 17). Multiple transverse inner support rods 11 are arranged parallel inside each inner template frame segment 16 (the two ends of the transverse inner support rod 11 are respectively hinged to the inner template frame segment 16). The transverse inner support rods 11 are telescopic. Preferably, each of the inner template frame segments 16 includes two rotatably connected "7"-shaped templates 16.1. When installing the inner template, the two "7"-shaped templates 16.1 are brought together by adjusting the transverse inner support rod 11 to form an inner template frame segment 16. The two inner template frame segments 16 are connected by an inner template middle section 17 to form a sub-inner template. At the same time, the two inner template middle sections 17 can be tightened by the transverse inner support rod 11. When it is necessary to remove the sub-inner template, it is only necessary to slide the two inner template middle sections 17 out of the two inner template frame segments 16 to remove it, thereby realizing quick assembly and disassembly of the inner template.

[0057] Furthermore, each layer of the inner template (including the equal-diameter inner template 3.2, the first variable-diameter inner template 3.1, and the second variable-diameter inner template 7) is equipped with reinforcing ribs 21, and the transverse inner support rods 11 are set inside the inner templates through the reinforcing ribs 21. At the same time, an operating platform is installed on the inner side of each layer of the inner template for workers to use.

[0058] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A method of constructing a thin-walled hollow pier, characterized by, The method comprises the following steps: Step 1, erecting a first set of outer formworks and installing trusses outside the outer formworks, and then pouring a solid section of a bridge pier bottom; each set of outer formworks is divided into three layers of sub-outer formworks from bottom to top, and each layer of the sub-outer formworks comprises four first and last connected sub-outer formworks which are installed by embracing through diagonal rods; Step 2, hoisting a first set of inner formworks on the top of the solid section of the bridge pier bottom, the first set of inner formworks is divided into one layer of first variable-diameter sub-inner formworks and two layers of equal-diameter sub-inner formworks from bottom to top, and each layer of the first variable-diameter sub-inner formworks and the equal-diameter sub-inner formworks comprises two inner formwork frame sections and a wedge-shaped inner formwork middle section arranged between the two inner formwork frame sections; Step 3, pouring a first section of hollow bridge piers between the first set of outer formworks and the first set of inner formworks, after solidification, removing two layers of sub-outer formworks at the lower part of the first set of outer formworks and one layer of first variable-diameter sub-inner formworks and one layer of equal-diameter sub-inner formworks at the lower part of the first set of inner formworks, and then successively lifting and erecting the removed two layers of sub-outer formworks on the remaining one layer of sub-outer formworks to form a second set of outer formworks, the bottom of the second set of outer formworks being supported by a bottom support, and lifting and erecting the removed one layer of equal-diameter sub-inner formworks on the remaining one layer of equal-diameter sub-inner formworks, and then erecting one layer of equal-diameter sub-inner formworks to form a second set of inner formworks, the bottom of the second set of inner formworks being supported by a bottom support; Step 4, pouring a second section of hollow bridge piers between the second set of outer formworks and the second set of inner formworks, after solidification, successively lifting and erecting and pouring according to step 3 until the hollow pier reaches the pouring height, and covering the pier cap beam; The inner formwork middle section is slidingly installed between the end portions of the two inner formwork frame sections, the two inner formwork middle sections are connected by transverse inner support rods, and a plurality of transverse inner support rods are arranged in parallel inside each inner formwork frame section; Each inner formwork frame section comprises two "7" type formworks connected by rotation, and the two "7" type formworks are closed by adjusting the transverse inner support rods when the inner formwork is installed.

2. The construction method of claim 1, wherein, In step 4, when the third set of inner formworks is erected until the penultimate set of inner formworks, the two layers of equal-diameter sub-inner formworks at the lower part of the previous set of inner formworks are lifted upwards, and when the last set of inner formworks is erected, only one layer of equal-diameter sub-inner formworks needs to be lifted upwards, and a second variable-diameter sub-inner formwork is erected on the equal-diameter sub-inner formwork, the diameter of the second variable-diameter sub-inner formwork gradually decreasing from bottom to top.

3. The construction method of claim 1, wherein, In the process of pouring each section of hollow bridge piers, a plurality of bottom supports are pre-embedded on the outer side and the inner side of each section of hollow bridge piers, respectively, and the remaining one layer of sub-outer formworks or equal-diameter sub-inner formworks are supported by the bottom supports.

4. The construction method of claim 1, wherein, Each truss comprises two oppositely arranged broken-line truss segments and two oppositely arranged straight-line truss segments, and the two broken-line truss segments and the two straight-line truss segments form a hexagonal truss around the upper part of each layer of sub-outer formworks.

5. The construction method according to claim 4, characterized in that, A ladder opening is arranged outside the connection between the broken-line truss segment and the straight-line truss segment, and a straight ladder is slidingly installed between the ladder openings of two adjacent trusses for workers to go up and down.

6. The construction method of claim 1, wherein, Vertical ribs are vertically arranged outside each set of outer formworks, and back bars are transversely arranged.

7. The construction method of claim 1, wherein, Four first sub-outer templates and four second sub-outer templates are arranged in a front-back symmetry and a left-right symmetry, respectively, the second sub-outer template comprises a straight connecting part and a bent corner part arranged at both ends of the straight connecting part, first inclined rod mounting seats are welded at both ends of the straight connecting part near the bent corner parts, respectively, second inclined rod mounting seats are arranged at both ends of the first sub-outer template, respectively, and inclined rods are arranged on the adjacent first and second inclined rod mounting seats.

8. The construction method of claim 1, wherein, The outer template is connected with the truss through a plurality of spaced apart and telescopic limiting connecting pieces, the limiting connecting piece comprises a connecting hook and a pad, the hook end of the connecting hook is hooked on the outer template, and the other end is provided with external threads, and the limiting connecting piece is limited on the truss through a nut and a pad.

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