Prestressed cantilever support structure and construction method of large cantilever cap beam

Abstract

A prestressed cantilever support structure for a large cantilever cap beam, comprising a bridge pier, a cap beam and a pedestal, wherein the bridge pier is located between the cap beam and the pedestal; the bridge pier is characterized in that the bridge piers are symmetrically arranged at both ends of the pedestal, and symmetrically arranged support columns are arranged on the sides of the bridge piers; the bottom of the support column is supported on the pedestal, and a support crossbeam is arranged above the support column, and a slope adjustment truss is arranged on the support crossbeam, which is against the bottom of the cap beam; the support crossbeam is provided with a support prestressed cable and a prestressed anchoring device matched with the support prestressed cable; compared with the prior art, a large cantilever structural system of the support is realized by tensioning the prestressed cable of the cap beam support, which can avoid interfering with driving by setting the support columns on the ground road lane, ensure smooth passage of vehicles below the cantilever position of the cap beam, and realize internal force control and displacement control of the support crossbeam by tensioning the support prestressed cable, which is convenient to construct, simple in structure, effective and feasible.

Description

Technical Field

[0001] The invention belongs to the technical field of road and bridge construction engineering structures, and in particular relates to a prestressed cantilever bracket structure of a large cantilever cap beam and a construction method. Background Art

[0002] At present, the support form of the large cantilever cap beam mainly adopts a multi-column continuous beam system, that is, multiple columns are set as the crossbeam support of the cap beam support to meet the force requirements of the support crossbeam. However, the multi-column continuous beam system interferes with the maintenance of the ground road under the bridge. Moving vehicles must avoid the support columns, and the lanes of the ground road under the bridge must be reduced, increasing the traffic pressure on the ground. Therefore, it is necessary to develop a new type of large cantilever cap beam support form to avoid the support columns occupying the ground road lanes, so as to solve the problem of conflict between the support columns and the ground road maintenance.

[0003] Chinese patent number CN110820561A discloses a large cantilever prestressed cap beam support device and construction method, which is characterized in that it includes a middle support column supported at the root of the cap beam cantilever, the middle support column is symmetrically arranged on both sides of the cap beam pier, and the bottom of the middle support column is supported on the pedestal where the cap beam pier is located; it also includes an end support column supported at the end of the cap beam cantilever, the bottom end of the end support column is supported on the ground by reinforced concrete, the upper ends of the middle support column and the end support column support the load-bearing beam, the load-bearing beam supports the slope-adjusting truss beam, and the slope-adjusting truss beam supports the cap beam bottom formwork.

[0004] The above-disclosed cap beam support device and construction method have steel pipe support columns of different heights arranged on both sides of the cap beam, and the steel pipe support columns extend along the bottom of the cap beam to the ground. This causes the steel pipe support columns to interfere with the ground road below the cap beam, affecting the lane setting of the ground road below the cap beam and increasing the traffic pressure on the ground. Summary of the invention

[0005] The present invention aims to overcome the defects in the above-mentioned prior art and to provide a prestressed cantilever support structure and construction method for a large cantilever cap beam which is simple in structure, safe and reliable, easy to construct and can effectively avoid the conflict between the cap beam column and the ground road maintenance.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is: a prestressed cantilever support structure of a large cantilever cap beam, including bridge piers, a cap beam and a pedestal, the bridge piers are located between the cap beam and the pedestal; it is characterized in that the bridge piers are symmetrically arranged at both ends of the pedestal, and symmetrically arranged support columns are provided on the sides of the piers; the bottom of the support column is supported on the pedestal, and a support cross beam is provided above the support column, and a slope adjustment truss is provided on the support cross beam to abut the bottom of the cap beam; the support cross beam is provided with a support prestressed cable and a prestressed anchoring device compatible with the support prestressed cable, and the support prestressed cable is arranged along the length direction of the support cross beam.

[0007] As a preferred solution of the present invention, support column parallel connections and support column diagonal braces are provided between the support columns on the same side of the oppositely arranged piers.

[0008] As a preferred solution of the present invention, the support column is a spiral steel pipe structure, and the support column is composed of a support column standard part and a plurality of support column heightening parts. The support column standard part and the support column heightening parts are connected by flanges, and adjacent support column heightening parts are also connected by flanges.

[0009] As a preferred solution of the present invention, a load-relief device is provided on the top of the support column, and the load-relief device is connected to the support crossbeam.

[0010] As a preferred solution of the present invention, the support cross beams are located on the support columns on the same side, and the support columns that are oppositely arranged are provided with support cross beams that are oppositely arranged.

[0011] As a preferred solution of the present invention, a horizontal connecting beam is provided between the relatively arranged support beams, a support distribution beam is provided on the relatively arranged support beams, and the slope adjustment truss is located on the support distribution beam.

[0012] As a preferred solution of the present invention, a support prestressed shock absorber is provided on the support cross beam, and the support prestressed cable passes through the support prestressed shock absorber.

[0013] As a preferred solution of the present invention, a protective structure is provided outside the pier.

[0014] A construction method for a prestressed cantilever support structure of a large cantilever cap beam, characterized in that it comprises the following steps:

[0015] Step A: Preset a cap in the ground, embed the pressure-bearing steel plate and anchor bolts on the cap, cast the bridge pier on the cap, and set up a protective structure between the bridge pier and the ground roadway;

[0016] Step B: erecting support columns on the cap, the support columns are arranged on both sides of the pier, and the bottom of the support columns are connected to the anchor bolt flanges. The erection of the support columns includes erecting support column heightening parts and support column standard parts. The number of support column heightening parts is set according to actual needs. The support column heightening parts and the support column standard parts are connected by flanges, and adjacent support column heightening parts are also connected by flanges.

[0017] Step C: Install support column parallel joints and support column diagonal braces between adjacent support columns, and install unloading devices on top of the support columns;

[0018] Step D: Install the support beam on the unloading device, install horizontal connecting braces between the support beams to strengthen the lateral stability of the support beams, lay the support distribution beam on the beam, and install the slope adjustment truss on the distribution beam.

[0019] Step E: installing a prestressed anchor device and a support prestressed shock absorber on the support crossbeam, the support prestressed cable passes through the support prestressed shock absorber, and the support prestressed cable is installed between the support prestressed anchor devices on both sides;

[0020] Step F: Install the cap beam bottom formwork, cap beam reinforcement skeleton and cap beam side formwork on the slope adjustment truss, and pour concrete for the cap beam. During the concrete pouring process, the prestressed cables of the support are tensioned in stages at the support prestressed anchoring device;

[0021] Step G: Curing the poured cap beam concrete and tensioning the cap beam steel strands. During the tensioning process of the cap beam steel strands, the support prestressed cables are released in stages at the support prestressed anchoring device.

[0022] Step H: dismantle the cap beam bottom formwork, cap beam reinforcement skeleton and cap beam side formwork; as a preferred embodiment of the present invention, the described.

[0023] As a preferred solution of the present invention, the unloading device is a tension bolt or a sand cylinder structure.

[0024] The beneficial effects of the present invention are as follows: compared with the prior art, a large cantilever structural system of the support is realized by tensioning the prestressed cables of the cap beam support, which can avoid interfering with driving by setting support columns on the ground road lane, ensure smooth passage of vehicles under the cantilever position of the cap beam, and realize internal force control and displacement control of the support crossbeam by tensioning the prestressed cables of the support. The construction is convenient, the structure is simple, and it is effective and feasible.

[0025] At the same time, the support columns are connected by splicing between the support column standard parts and the support column heightening parts, so that the height of the support columns can be set according to actual needs, which is convenient for the erection and construction of the support columns. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a cross-sectional schematic diagram of the present invention;

[0027] Figure 2 It is a side schematic diagram of the present invention;

[0028] Figure 3 It is a plan view schematic diagram of the present invention;

[0029] The reference numerals in the figure are: pier 101, cap beam 102, abutment 103, enclosure structure 104, ground road carriageway 105, support column 201, support column standard parts 202, support column heightening parts 203, support column parallel connection 204, support column diagonal brace 205, unloading device 206, support cross beam 301, support distribution beam 302, slope adjustment truss 303, cross beam horizontal connecting brace 304, support prestressed anchoring device 401, support prestressed cable 402, support prestressed shock absorber 403. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] like Figure 1-3 As shown, a prestressed cantilever support structure of a large cantilever cap beam comprises a pier 101, a cap beam 102 and a pedestal 103, wherein the pier 101 is located between the cap beam 102 and the pedestal 103; the piers 101 are symmetrically arranged at both ends of the pedestal 103, and symmetrically arranged support columns 201 are arranged on the sides of the piers 101; the bottom of the support column 201 is supported on the pedestal 103, and a support cross beam 301 is arranged above the support column 201, and a slope adjustment truss 303 abutting against the bottom of the cap beam 102 is arranged on the support cross beam 301; a support prestressed cable 402 and a support prestressed anchoring device 401 matched with the support prestressed cable 402 are arranged on the support cross beam 301, and the support prestressed cable 402 is arranged along the length direction of the support cross beam 301.

[0032] The pedestal 103 is arranged under the ground, the bottoms of the piers 101 and the support columns 201 are arranged on the pedestal 103, the pedestal 103 is provided with embedded pressure-bearing steel plates and anchor bolts, two piers 101 of the same size are arranged on the pedestal 103, two support columns 201 are arranged on both sides of a pier 101, and four support columns 201 are arranged on the pedestal 103, the four support columns 201 are arranged at the four corners of the pedestal 103, and the four support columns 201 are arranged in an array.

[0033] The top of the support column 201 is against the support beam 301, one support beam 301 corresponds to two support columns 201, and two parallel support beams 301 are provided above the pedestal 103. The size of the slope-adjusting truss 303 is set according to the size of the bottom of the cap beam 102. The slope-adjusting truss 303 is set along the length direction of the cap beam 102, and the top of the slope-adjusting truss 303 is against the entire bottom of the cap beam 102.

[0034] A support column parallel connection 204 and a support column diagonal brace 205 are provided between the support columns 201 on the same side of the relatively arranged piers 101. The support columns 201 on the same side include two support column parallel connections 204 of different heights and a plurality of support column diagonal braces 205. The support column diagonal brace 205 is obliquely arranged between the two support column parallel connections 204. The plurality of support column diagonal braces 205 are connected in sequence. The plurality of support column diagonal braces 205 are fixedly connected by welding, and the support column parallel connection 204 and the support column diagonal brace 205 are also fixedly connected by welding, and the support column parallel connection 204 and the support column diagonal brace 205 are also fixedly connected to the support column 201 by welding.

[0035] The support column 201 is a spiral steel pipe structure, and the support column 201 is composed of a support column standard part 202 and a plurality of support column heightening parts 203. The support column standard part 202 and the support column heightening parts 203 are connected by flanges, and adjacent support column heightening parts 203 are also connected by flanges.

[0036] The number of the support column heightening members 203 is set according to actual needs, and the number of the support column heightening members 203 is set according to the required height of the support column 201 and the height of the cap beam 102 .

[0037] A unloading device 206 is provided on the top of the support column 201 , and the unloading device 206 is connected to the support beam 301 . The unloading device 206 can adopt a tension bolt or a sand cylinder structure. The unloading device 206 is fixedly connected to the top of the support column 201 , and the top of the unloading device 206 is against the support beam 301 .

[0038] The support cross beam 301 is located on the support column 201 on the same side, and the support column 201 that is arranged oppositely is provided with a support cross beam 301 that is arranged oppositely, and a horizontal connecting beam 304 is provided between the support cross beams 301 that are arranged oppositely to strengthen the lateral stability of the support cross beam, and the support cross beams 301 that are arranged oppositely are provided with a support distribution beam 302, and the slope adjustment truss 303 is located on the support distribution beam 302, and a support prestressed shock absorber 403 is provided on the support cross beam 301, and the support prestressed cable 402 passes through the support prestressed shock absorber 403.

[0039] The support prestressed cable 402 may be made of steel strands, precision-rolled threaded steel bars, parallel steel wires and other structures. The support prestressed cable 402 is arranged within a suitable length range according to the stress behavior of the support cross beam 301 to ensure the safety of the support cross beam stress. The support prestressed shock absorber 403 is installed at a suitable position on the support cross beam 301, and the support prestressed cable 402 passes through the support prestressed shock absorber 403 to ensure the linear smoothness of the support prestressed cable 402. The support prestressed shock absorber 403 is installed at a suitable position on the support cross beam 301, and the support prestressed cable 402 passes through the support prestressed shock absorber 403 to ensure the linear smoothness of the support prestressed cable 402.

[0040] A protective structure 104 is provided outside the bridge pier 101 , and the protective structure 104 is provided between the outside of the bridge pier 101 and the ground roadway 105 to ensure that the construction area and the ground roadway 105 area do not interfere with each other.

[0041] The actual production process includes the following steps:

[0042] Step A: a cap 103 is preset in the ground, and a pressure-bearing steel plate and anchor bolts are embedded on the cap 103, a bridge pier 101 is cast on the cap 103, and a retaining structure 104 is set between the bridge pier 101 and the ground road lane 105 to ensure that the construction area and the ground road lane 105 area do not interfere with each other.

[0043] Step B: erect support columns 201 on the pedestal 103. The support columns 201 are arranged on both sides of the pier 101, and the bottoms of the support columns 201 are flange-connected with the anchor bolts. The erection of the support columns 201 includes erecting support column heightening components 203 and support column standard components 202. The number of support column heightening components 203 is set according to actual needs. The support column heightening components 203 and the support column standard components 202 are connected by flanges, and adjacent support column heightening components 203 are also connected by flanges. The height of the support column 201 is less than the height of the pier 101.

[0044] Step C: Install support column parallel joints 204 and support column diagonal braces 205 between adjacent support columns 201, and install unloading devices 206 on the tops of the support columns. The support columns 201 on the same side include two support column parallel joints 204 and multiple support column diagonal braces 205 of different heights. The support column diagonal braces 205 are tilted between the two support column parallel joints 204. The multiple support column diagonal braces 205 are connected in sequence. The multiple support column diagonal braces 205 are fixedly connected by welding, and the support column parallel joints 204 and the support column diagonal braces 205 are also fixedly connected by welding. The support column parallel joints 204 and the support column diagonal braces 205 are also fixedly connected to the support columns 201 by welding. The unloading device 206 is a tension bolt or a sand cylinder structure.

[0045] Step D: Install the support beam 301 on the unloading device 206, install horizontal beam connecting braces 304 between the support beams 301 to enhance the lateral stability of the support beams 301, lay the support distribution beam 302 on the beam, and install the slope adjustment truss 303 on the distribution beam.

[0046] Step E: Install the support prestressed anchor device 401 and the support prestressed shock absorber 403 on the support cross beam 301 , the support prestressed cable 402 passes through the support prestressed shock absorber 403 , and the support prestressed cable 402 is installed between the support prestressed anchor devices 401 on both sides.

[0047] The support prestressed cable 402 may be made of steel strands, precision-rolled threaded steel bars, parallel steel wires and other structures. The support prestressed cable 402 is arranged within a suitable length range according to the stress behavior of the support cross beam 301 to ensure the safety of the support cross beam stress. The support prestressed shock absorber 403 is installed at a suitable position on the support cross beam 301, and the support prestressed cable 402 passes through the prestressed shock absorber 403 to ensure that the line of the support prestressed cable 402 is smooth. The support prestressed shock absorber 403 is installed at a suitable position on the support cross beam 301, and the support prestressed cable 402 passes through the prestressed shock absorber 403 to ensure that the line of the support prestressed cable 402 is smooth.

[0048] Step F: Install the cap beam bottom formwork, cap beam reinforcement skeleton and cap beam side formwork on the slope adjustment truss 303, and pour concrete for the cap beam 102. During the concrete pouring process, the support prestressed cable 402 is tensioned in stages at the support prestressed anchor device 401;

[0049] Step G: Curing the poured cap beam 102 concrete and tensioning the cap beam 102 steel bundles, that is, tensioning the support prestressed cables 402. During the tensioning of the cap beam 102 steel bundles, the support prestressed cables 402 are released in stages at the support prestressed anchoring device 401.

[0050] Step H: Remove the cap beam bottom formwork, cap beam reinforcement frame and cap beam side formwork.

[0051] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention; therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0052] Although this article makes use of the following figures more frequently: pier 101, cap beam 102, abutment 103, enclosure structure 104, ground road carriageway 105, support column 201, support column standard part 202, support column heightening part 203, support column parallel joint 204, support column diagonal brace 205, unloading device 206, support cross beam 301, support distribution beam 302, slope adjustment truss 303, cross beam horizontal connecting brace 304, support prestressed anchor device 401, support prestressed cable 402, support prestressed shock absorber 403 and other terms, the possibility of using other terms is not excluded; these terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. A construction method for a prestressed cantilever support structure of a large cantilever cap beam, characterized in that: The invention comprises a bridge pier (101), a cap beam (102) and a cap platform (103), wherein the bridge pier (101) is located between the cap beam (102) and the cap platform (103); the bridge pier (101) is symmetrically arranged at both ends of the cap platform (103), and symmetrically arranged support columns (201) are arranged on the side of the bridge pier (101); the bottom of the support column (201) is supported on the cap platform (103), and a support cross beam (301) is arranged above the support column (201), and a slope adjustment truss (303) is arranged on the support cross beam (301) and is against the bottom of the cap beam (102); the support cross beam (301) A support prestressed cable (402) and a support prestressed anchoring device (401) matched with the support prestressed cable (402) are provided on the support, the support prestressed cable (402) is arranged along the length direction of the support cross beam (301), the support prestressed cable (402) is arranged in a suitable length range according to the stress behavior of the support cross beam (301), so as to ensure the safety of the support cross beam stress, a prestressed shock absorber (403) is installed at a suitable position on the support cross beam (301), the support prestressed cable (402) passes through the prestressed shock absorber (403), so as to ensure the linear smoothness of the support prestressed cable (402), and the steps are included: Step A: a cap (103) is preset in the ground, and a pressure-bearing steel plate and anchor bolts are pre-embedded on the cap (103), a bridge pier (101) is cast on the cap (103), and a protective structure (104) is set between the bridge pier (101) and a ground roadway (105); Step B: erecting support columns (201) on the pedestal (103), the support columns (201) being arranged on both sides of the pier (101), and the bottom of the support columns (201) being connected to the anchor bolt flanges, the erection of the support columns (201) comprising erecting support column heightening components (203) and support column standard components (202), the number of support column heightening components (203) being set according to actual needs, the support column heightening components (203) and the support column standard components (202) being connected via flanges, and adjacent support column heightening components (203) being connected via flanges; Step C: installing support column parallel joints (204) and support column diagonal braces (205) between adjacent support columns (201), and installing unloading devices (206) on the tops of the support columns; Step D: Installing a support beam (301) on the unloading device (206), installing a horizontal beam connecting brace (304) between the support beams (301) to strengthen the lateral stability of the support beams (301), laying a support distribution beam (302) on the beam, and installing a slope adjustment truss (303) on the distribution beam; Step E: installing a support prestressed anchor device (401) and a support prestressed shock absorber (403) on the support cross beam (301), the support prestressed cable (402) passes through the support prestressed shock absorber (403), and the support prestressed cable (402) is installed between the support prestressed anchor devices (401) on both sides; Step F: installing a cap beam bottom formwork, a cap beam reinforcement frame and a cap beam side formwork on the slope adjustment truss (303), and pouring concrete for the cap beam (102). During the concrete pouring process, the support prestressed cable (402) is tensioned in stages at the support prestressed anchoring device (401); Step G: curing the cast cap beam (102) concrete and tensioning the cap beam (102) steel strands. During the tensioning process of the cap beam (102) steel strands, the support prestressed anchoring device (401) releases the support prestressed cable (402) in stages. Step H: Remove the cap beam bottom formwork, cap beam reinforcement frame and cap beam side formwork.

2. The construction method of a prestressed cantilever support structure of a large cantilever cap beam according to claim 1 is characterized in that: The unloading device (206) is a tension bolt or a sand cylinder structure.

3. The construction method of a prestressed cantilever support structure of a large cantilever cap beam according to claim 1 is characterized in that: A support column parallel connection (204) and a support column diagonal brace (205) are provided between the support columns (201) on the same side of the bridge piers (101) arranged opposite to each other.

4. The construction method of a prestressed cantilever support structure of a large cantilever cap beam according to claim 1, characterized in that: The support column (201) is a spiral steel pipe structure, and the support column (201) is composed of a support column standard part (202) and a plurality of support column heightening parts (203). The support column standard part (202) and the support column heightening parts (203) are connected by flanges, and adjacent support column heightening parts (203) are also connected by flanges.

5. The construction method of a prestressed cantilever support structure of a large cantilever cap beam according to claim 4, characterized in that: A load-relief device (206) is provided on the top of the support column (201), and the load-relief device (206) is connected to the support crossbeam (301).

6. The construction method of a prestressed cantilever support structure of a large cantilever cap beam according to claim 1, characterized in that: The support cross beam (301) is located on the support column (201) on the same side, and the support columns (201) arranged opposite to each other are provided with support cross beams (301) arranged opposite to each other.

7. The construction method of a prestressed cantilever support structure of a large cantilever cap beam according to claim 6, characterized in that: A horizontal beam connecting brace (304) is provided between the support beams (301) arranged opposite to each other, a support distribution beam (302) is provided on the support beams (301) arranged opposite to each other, and a slope adjustment truss (303) is located on the support distribution beam (302).

8. The construction method of a prestressed cantilever support structure of a large cantilever cap beam according to claim 1, characterized in that: A protective structure (104) is provided outside the bridge pier (101).

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