Cast-in-cantilever construction method for enabling left side and right side of continuous beam to cross existing road in single-line mode

Abstract

The invention discloses a cantilever casting construction method for single-line crossing of the left side and the right side of a continuous beam on an existing road. The construction method comprises the steps of construction of lower structures of main piers and side piers on a left line, construction of pier tops, construction of continuous beam standard sections, cast-in-place construction of side span closure sections, construction of box girders of middle span closure sections, construction on a hanging bracket and dismantling of construction loads; on the right line, foundation treatment, support position paying-off, erecting, checking and adjusting, longitudinal and transverse square timber laying, support, bottom formwork and side formwork mounting, bottom formwork leveling, bottom plate and side plate steel bar binding, corrugated pipe, inner formwork and end formwork mounting, top plate steel bar binding and concrete pouring are conducted; and maintaining, removing a bottom template and a bracket, paving a waterproof layer and a protective layer on a bridge floor of a first falling beam, and mounting a bridge floor system. Cast-in-place construction is conducted on the two sides through hanging basket cantilever casting and a support method, and the problems that the span is large and construction is difficult are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cantilever casting construction, and more particularly to a cantilever casting construction method in which left and right sides of a continuous beam respectively span an existing highway in a single line. Background Art

[0002] The cantilever casting method refers to a construction method in which a working platform is set up on both sides of the bridge pier, cement concrete beams are cantilevered and cast in a balanced manner towards the mid-span in sections, and prestressing is applied section by section.

[0003] At present, the existing cantilever casting construction method needs to consider the construction conditions on both sides of the cantilever casting. When the left and right sides of the continuous beam need to cross the existing highway respectively, the cantilever casting method is used, the span is large and the construction is more difficult.

[0004] Therefore, how to provide a cantilever casting construction method with high safety and feasibility and low construction difficulty, in which a continuous beam with single lines on both sides crosses an existing highway, is an urgent problem that technicians in this field need to solve. Summary of the Invention

[0005] In view of this, the present invention provides a cantilever casting construction method for a continuous beam with single lines on both sides crossing an existing highway, aiming to solve one of the problems in the above-mentioned background technology, with high safety and feasibility and low construction difficulty.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A cantilever casting construction method for a continuous beam with single lines on both sides crossing an existing highway comprises:

[0008] The left line adopts cantilever casting construction with hanging basket, which includes the following steps:

[0009] Step 1: Construction of the main pier and side pier substructures, completion of pier foundation and pier body construction, installation of the main pier side supports, and use of cantilever brackets according to the height of the main pier;

[0010] Step 2: The pier top 0# block is constructed using the scaffolding method. The box girder 0 segment formwork is erected on the scaffolding next to the main pier. Rebars are tied, prestressed pipes are installed, and concrete for the box girder 0 segment is poured. The longitudinal, transverse, and vertical prestressed steel strands are symmetrically tensioned, and a cantilever construction basket is installed.

[0011] Step 3: The standard segment of the continuous beam is constructed by cantilever casting using a diamond-shaped hanging basket. The construction of box beam segment No. 1 is carried out on the diamond-shaped hanging basket. Formwork is erected, steel bars are tied, prestressed pipes are installed, and concrete for box beam segment No. 1 is poured. The longitudinal, transverse, and vertical prestressed steel tendons are symmetrically tensioned. The diamond-shaped hanging basket is moved and box beam segments 2# to N# are poured in sequence according to the above steps.

[0012] Step 4: The side span closure section is cast in situ using the Bailey beam support method. The diamond-shaped construction basket is removed, and the side pier supports are installed. The supports are preloaded, and the side span box girder segments are cast in situ on the supports. Formwork is erected, steel bars are tied, prestressed pipes are installed, and the box girder segments are cast in situ.

[0013] Step 5: The box girder of the middle span closure section is constructed using the hanger method. The box girder side span closure section is constructed on the bracket. The reinforcement skeleton is installed, the formwork is erected, the steel bars are tied, the prestressed steel tendons are installed, and the concrete of the box girder of the side span closure section is poured. The temporary restraints of the side piers are released, the prestressed steel tendons of the side span closure section are symmetrically tensioned, the bracket is removed, and the support is officially loaded.

[0014] Step 6: Construct the mid-span closure section on the hanger, install the rigid frame, erect the formwork, tie the steel bars, install the prestressed pipes, pour the concrete, and symmetrically tension the longitudinal tendons of the mid-span closure;

[0015] Step 7: Remove the entire bridge construction load and proceed with the construction of the bridge deck system and ancillary facilities;

[0016] The right line adopts the cast-in-place construction method of bracket, which includes the following steps:

[0017] Construction preparation, foundation treatment → Strut position marking → Strut erection → Strut calibration and adjustment → Laying of vertical and horizontal timbers → Installation of supports → Installation of bottom formwork and side formwork → Leveling of bottom formwork → Binding of bottom plate and side plate reinforcement → Installation of corrugated pipe, inner formwork and end formwork → Binding of top plate reinforcement → Concrete pouring → Concrete curing → Removal of side formwork and inner formwork → Prestressing → Grouting and sealing of ends → Curing → Removal of bottom formwork and Struts, Dropping of beams → Installation of waterproof layer and protective layer on bridge deck → Installation of bridge deck system.

[0018] Furthermore, two flow working surfaces are set for each continuous beam of the continuous beam superstructure constructed by the hanging basket cantilever casting, and two hanging baskets are set for symmetrical construction on each main pier. The cast-in-place of a "T" joint plus the side span joint section is a flow working surface, and each flow working surface operates in parallel.

[0019] Furthermore, each of the continuous beams in the cantilever casting construction of the hanging basket is operated in parallel by an independent construction unit, and the lower structure of the continuous beam adopts parallel operation on a flow working surface.

[0020] Furthermore, when the hanging basket cantilever casting construction is carried out for the closure, the process is carried out from the side span closure section to the middle span closure section. The side span closure section is cast in situ using a bracket, and the middle span closure section is constructed using a hanger method.

[0021] Furthermore, the scaffolding foundation of the cast-in-place construction by the scaffolding method is made of concrete, the columns are spiral pipe piles, I40b steel is used as the horizontal distribution beam above the columns, the longitudinal beam is made of shell beam, I25b steel is laid on it to form a construction platform, and a safety net is hung.

[0022] Furthermore, the inner formwork of the beam body in the cast-in-place construction using the support method adopts a hydraulic steel formwork, and the outer formwork of the beam body adopts a large steel formwork.

[0023] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a cantilever casting construction method for a continuous beam with a single line on the left and right sides respectively crossing an existing highway. By adopting hanging basket cantilever casting and bracket method cast-in-place construction on the left and right sides respectively of the continuous beam, the problem of construction difficulty caused by a large span can be solved, and the construction safety and feasibility are high, and the construction difficulty is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0025] Figure 1 A flow chart of the cantilever casting construction process provided by the present invention;

[0026] Figure 2 This is a flowchart of the cast-in-place construction process using the bracket method provided by the present invention;

[0027] Figure 3A —3G is a schematic diagram of the cantilever casting construction provided by the present invention.

[0028] Among them: 1 is the main pier; 2 is the side pier; 3 is the side span joint section; 4 is the middle span joint section. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] See also Figure 1-3G The embodiment of the present invention discloses a cantilever casting construction method for a continuous beam with single lines on both sides crossing an existing highway, comprising:

[0031] The left line adopts cantilever casting construction with hanging basket, which includes the following steps:

[0032] Step 1: Construction of the lower structure of the main pier 1 and side pier 2, completion of the pier foundation and pier body construction, installation of the pier side support of the main pier 1, using a cantilever bracket according to the height of the main pier 1;

[0033] Step 2: The pier top 0# block is constructed using the scaffolding method. The box girder 0 segment formwork is erected on the scaffolding next to the main pier 1. Rebars are tied, prestressed pipes are installed, and concrete for the box girder 0 segment is poured. The longitudinal, transverse, and vertical prestressed steel strands are symmetrically tensioned, and a cantilever construction basket is installed.

[0034] Step 3: The standard segment of the continuous beam is constructed by cantilever casting using a diamond-shaped hanging basket. The construction of box beam segment No. 1 is carried out on the diamond-shaped hanging basket. Formwork is erected, steel bars are tied, prestressed pipes are installed, and concrete for box beam segment No. 1 is poured. The longitudinal, transverse, and vertical prestressed steel tendons are symmetrically tensioned. The diamond-shaped hanging basket is moved and box beam segments 2# to N# are poured in sequence according to the above steps.

[0035] Step 4: The side span closure section 3 is cast in situ using the Bailey beam support method. The diamond-shaped construction basket is removed, and the pier-side supports of side pier 2 are installed. The supports are preloaded, and the cast-in-situ section of the side span box girder is constructed on the supports. Formwork is erected, steel bars are tied, prestressed pipes are installed, and the cast-in-situ concrete of the box girder section is poured.

[0036] Step 5: The box girder of the middle span closure section 4 is constructed using the hanger method. The box girder of the side span closure section 3 is constructed on the support. The reinforcement skeleton is installed, the formwork is erected, the steel bars are tied, the prestressed steel tendons are installed, and the concrete of the box girder of the side span closure section 3 is poured. The temporary restraint of the side pier 2 is released, the prestressed steel tendons of the side span closure section 3 are symmetrically tensioned, the support is removed, and the support is officially loaded.

[0037] Step 6: Construct the mid-span closure section 4 on the hanger, install the rigid frame, erect the formwork, tie the steel bars, install the prestressed pipes, pour the concrete, and symmetrically tension the longitudinal tendons of the mid-span closure;

[0038] Step 7: Remove the entire bridge construction load and proceed with the construction of the bridge deck system and ancillary facilities;

[0039] The right line adopts the cast-in-place construction method of bracket, which includes the following steps:

[0040] Construction preparation, foundation treatment → Strut position marking → Strut erection → Strut calibration and adjustment → Laying of vertical and horizontal timbers → Installation of supports → Installation of bottom formwork and side formwork → Leveling of bottom formwork → Binding of bottom plate and side plate reinforcement → Installation of corrugated pipe, inner formwork and end formwork → Binding of top plate reinforcement → Concrete pouring → Concrete curing → Removal of side formwork and inner formwork → Prestressing → Grouting and sealing of ends → Curing → Removal of bottom formwork and Struts, Dropping of beams → Installation of waterproof layer and protective layer on bridge deck → Installation of bridge deck system.

[0041] In this embodiment, two flow working surfaces are set for each continuous beam of the continuous beam superstructure constructed by cantilever casting of continuous beam hanging baskets, and two hanging baskets are set for symmetrical construction on each continuous beam main pier 1. The cast-in-place of a "T" joint plus the side span joint section 3 is a flow working surface, and each flow working surface operates in parallel.

[0042] In this embodiment, each continuous beam in the cantilever casting construction of the continuous beam hanging basket is operated in parallel by an independent construction unit, and the lower structure of the continuous beam adopts parallel operation on a flow working surface.

[0043] In this embodiment, when the continuous beam hanging basket cantilever casting construction is carried out for closure, the process is carried out from the side span closure section 3 to the middle span closure section 4. The side span closure section 3 is cast in situ using a bracket, and the middle span closure section 4 is constructed using a hanger method.

[0044] In this embodiment, the falsework foundation of the continuous beam support method cast-in-place construction is made of concrete, the columns are spiral pipe piles, I40b steel is used as the horizontal distribution beam above the columns, the longitudinal beam is made of shell beam, and I25b steel is laid on it to form a construction platform, and a safety net is hung.

[0045] In this embodiment, the inner formwork of the beam body in the cast-in-place construction using the continuous beam support method adopts a hydraulic steel formwork, and the outer formwork of the beam body adopts a large steel formwork.

[0046] In addition, in this embodiment, the main beam 0# block of the continuous beam is cast in one go using a mass concrete process. Based on the height of the main pier 1 column, safety protection requirements, and on-site geological conditions, the support method is selected for construction.

[0047] After the support is erected, pour the 0# section after pre-compression. Install a diamond hanging basket on the 0# section and pre-compress it. Then, pour other standard beam sections symmetrically on both sides using the diamond hanging basket.

[0048] During construction, attention should be paid to the adjustment of the beam line shape and construction safety protection. Small machinery, formwork, steel bars, prestressed steel strands and other materials should be transported by lifting machinery, and modular scaffolding should be used for the up and down passages for construction personnel.

[0049] Concrete is mixed centrally, transported to the site by tank trucks, and poured using pump trucks.

[0050] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0051] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily 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 is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cantilever casting construction method for a continuous beam with single lines on both sides crossing an existing highway, characterized in that: include: The left line adopts cantilever casting construction with hanging basket, which includes the following steps: Step 1: Construction of the main pier and side pier substructures, completion of pier foundation and pier body construction, installation of the main pier side supports, and use of cantilever brackets according to the height of the main pier; Step 2: The pier top 0# block is constructed using the scaffolding method. The box girder 0 segment formwork is erected on the scaffolding next to the main pier. Rebars are tied, prestressed pipes are installed, and concrete for the box girder 0 segment is poured. The longitudinal, transverse, and vertical prestressed steel strands are symmetrically tensioned, and a cantilever construction basket is installed. Step 3: The standard segment of the continuous beam is constructed by cantilever casting using a diamond-shaped hanging basket. The construction of box beam segment No. 1 is carried out on the diamond-shaped hanging basket. Formwork is erected, steel bars are tied, prestressed pipes are installed, and concrete for box beam segment No. 1 is poured. The longitudinal, transverse, and vertical prestressed steel tendons are symmetrically tensioned. The diamond-shaped hanging basket is moved and box beam segments 2# to N# are poured in sequence according to the above steps. Step 4: The side span closure section is cast in situ using the Bailey beam support method. The diamond-shaped construction basket is removed, and the side pier supports are installed. The supports are preloaded, and the side span box girder segments are cast in situ on the supports. Formwork is erected, steel bars are tied, prestressed pipes are installed, and the box girder segments are cast in situ. Step 5: The box girder of the middle span closure section is constructed using the hanger method. The box girder side span closure section is constructed on the bracket. The reinforcement skeleton is installed, the formwork is erected, the steel bars are tied, the prestressed steel tendons are installed, and the concrete of the box girder of the side span closure section is poured. The temporary restraints of the side piers are released, the prestressed steel tendons of the side span closure section are symmetrically tensioned, the bracket is removed, and the support is officially loaded. Step 6: Construct the mid-span closure section on the hanger, install the rigid frame, erect the formwork, tie the steel bars, install the prestressed pipes, pour the concrete, and symmetrically tension the longitudinal tendons of the mid-span closure; Step 7: Remove the entire bridge construction load and proceed with the construction of the bridge deck system and ancillary facilities; The right line adopts the cast-in-place construction method of bracket, which includes the following steps: Construction preparation, foundation treatment → Strut position marking → Strut erection → Strut calibration and adjustment → Laying of vertical and horizontal timbers → Installation of supports → Installation of bottom formwork and side formwork → Leveling of bottom formwork → Binding of bottom plate and side plate reinforcement → Installation of corrugated pipe, inner formwork and end formwork → Binding of top plate reinforcement → Concrete pouring → Concrete curing → Removal of side formwork and inner formwork → Prestressing → Grouting and sealing of ends → Curing → Removal of bottom formwork and Struts, Dropping of beams → Installation of waterproof layer and protective layer on bridge deck → Installation of bridge deck system.

2. The cantilever casting construction method for a continuous beam with single lines on both sides crossing an existing highway according to claim 1, characterized in that: Two flow working surfaces are set for each continuous beam of the continuous beam superstructure constructed by the hanging basket cantilever casting, and two hanging baskets are set for symmetrical construction on each main pier. The cast-in-place of a "T" joint plus the side span joint section is a flow working surface, and each flow working surface operates in parallel.

3. The cantilever casting construction method for a continuous beam with single lines on both sides crossing an existing highway according to claim 1, characterized in that: Each of the continuous beams in the cantilever casting construction of the hanging basket is operated in parallel by an independent construction unit, and the lower structure of the continuous beam adopts parallel operation on a flow working surface.

4. The cantilever casting construction method for a continuous beam with single lines on both sides crossing an existing highway according to claim 1, characterized in that: When the hanging basket cantilever casting construction is carried out for closure, the process is carried out from the side span closure section to the middle span closure section. The side span closure section is cast in situ using a bracket, and the middle span closure section is constructed using a hanger method.

5. The cantilever casting construction method for a continuous beam with single lines on both sides crossing an existing highway according to claim 1, characterized in that: The scaffolding foundation of the cast-in-place construction method is made of concrete, the columns are spiral pipe piles, I40b steel is used as the horizontal distribution beam above the columns, the longitudinal beam is made of shell beam, I25b steel is laid on it to form a construction platform, and a safety net is hung.

6. The cantilever casting construction method for a continuous beam with single lines on both sides crossing an existing highway according to claim 1, characterized in that: The inner formwork of the beam body in the cast-in-situ construction using the support method adopts a hydraulic steel formwork, and the outer formwork of the beam body adopts a large steel formwork.

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