Construction method of deepwater large-span straining beam

Abstract

The invention discloses a construction method of a deepwater large-span straining beam, which comprises the following steps of: firstly constructing a straining beam section in a cofferdam in a bearing platform cofferdam, synchronously prefabricating a middle straining beam cavity prefabricated section, and after a pier body is out of water, cutting off a conflict part between a steel pipe pile of the bearing platform cofferdam and the straining beam in the range of the straining beam; the straining beam cavity prefabricated section is integrally hoisted to the top of the cut cofferdam steel pipe pile, water is pumped in the cofferdam, closure section cast-in-place hanging brackets between the two ends of the straining beam cavity prefabricated section and the poured straining beam section in the cofferdam are installed, concrete of the straining beam closure section and a cavity in the straining beam cavity prefabricated section is poured, and after the concrete reaches the design strength, the straining beam cavity prefabricated section is cut off. And dismantling the closure section cast-in-place hanging bracket and the bearing platform cofferdam to obtain the deepwater large-span straining beam. The construction method is easy to operate and short in construction period, equipment and a large amount of material investment are reduced, and construction cost and risks are greatly reduced.

Description

Technical Field

[0001] The invention relates to the field of bridge construction, and in particular to a construction method for a deep-water large-span tie beam. Background Art

[0002] With the rapid development of my country's economy, the construction of transportation infrastructure has also been vigorously carried out, and the number of bridges built on rivers and lakes has increased. The bridge engineering tie beam is a structure connecting two or more piles and piers, which increases the overall stiffness and improves the stress of the pile and pier structure.

[0003] The conventional construction methods for deep-water large-span tie beams mainly include the integral pedestal cofferdam method and the deep-water tie beam hanging box cofferdam method. Both methods are characterized by large equipment and material investment, long construction period and high safety risks. Summary of the invention

[0004] The purpose of the present invention is to propose a construction method for deep-water large-span tie beams, which is simple to operate, has a short construction period, reduces the investment in equipment and a large amount of materials, greatly reduces construction costs and risks, and effectively solves the problem that existing deep-water tie beams need to be re-set with tie beam hanging box cofferdams or integral pedestal cofferdams for construction.

[0005] The object of the present invention is to realize: A construction method for a deepwater large-span tie beam, characterized in that the specific construction steps are as follows: A. Construct two cap cofferdams at the same pier location, and cast the cap and pier body in each cap cofferdam; B. Construct a cofferdam inner tie beam section on each of the upper inner walls of the two piers; C. Synchronously prefabricate the tie beam cavity prefabricated sections on an open space outside the site; D. After the pier body is out of water, the steel pipe piles of the cap cofferdam within the range of the tie beam are cut underwater to the bottom elevation of the tie beam to obtain the steel pipe piles of the cofferdam after cutting; E. Integrally hoist the prefabricated hollow section of the tie beam to the top of the steel pipe pile of the cofferdam after cutting, between the two cast inner tie beam sections of the cofferdam, pump out water in the cap cofferdam, and stop the water; F. Install cast-in-place hangers for the joint sections at the joint range between the two ends of the prefabricated tie beam cavity prefabricated section and the cast cofferdam inner tie beam section; G. Pour the concrete of the tie beam closure section on the cast-in-place hanger of the closure section; H. pouring concrete in the cavity of the precast section of the tie beam cavity; I. When the concrete in the cavity of the tie beam joint section and the precast section of the tie beam cavity reaches the designed strength, remove the cast-in-place hangers and the pedestal cofferdam of the joint section to obtain the deep-water large-span tie beam.

[0006] The present invention adopts the method of constructing the tie beam section inside the cofferdam first, and prefabricating the middle tie beam cavity prefabricated section simultaneously, after the pier body is out of water, cutting off the conflicting part between the cofferdam steel pipe pile of the cofferdam and the tie beam within the range of the tie beam, and then hoisting the tie beam cavity prefabricated section as a whole to the top of the cofferdam steel pipe pile after the cutting off, pumping water inside the cofferdam, installing cast-in-place hangers for the joint section between the two ends of the tie beam cavity prefabricated section and the cast tie beam section inside the cofferdam, pouring concrete for the joint section of the tie beam and the cavity inside the tie beam cavity prefabricated section, and after the concrete reaches the designed strength, dismantling the cast-in-place hangers for the joint section and the cofferdam of the cofferdam to obtain a deep-water large-span tie beam.

[0007] Therefore, the present invention has the following advantages: 1. It is only necessary to design and construct a single small cap cofferdam according to the size of the cap, without setting up a large-sized overall cap cofferdam to surround all the caps, which greatly saves cofferdam structural materials, bottom sealing concrete, construction costs and construction period; 2. Only cast-in-place hangers are set up for the joint section, and there is no need to set up a large-scale cast-in-place support structure for the entire system beam; 3. The tie beam section and the tie beam cavity prefabricated section in the cofferdam can be constructed simultaneously with the pier structure, which does not occupy the construction period and effectively saves the construction period; 4. The use of prefabricated hollow sections in the middle of the tie beam can effectively reduce the lifting weight of the large-span tie beam and reduce the investment in large-scale lifting equipment; 5. Simple operation, short construction period, reduced equipment and large material investment, greatly reducing construction costs and risks.

[0008] The invention effectively solves the problem that the existing deep-water tie beams need to be re-installed with tie beam hanging box cofferdams or integral bearing platform cofferdams for construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is an elevation drawing of the deepwater long-span tie beam construction; Figure 2 Plans for the construction of long-span tie beams in deep water; In the figure: 1 is the cap; 2 is the pier body; 3 is the cap cofferdam; 4 is the tie beam section inside the cofferdam; 5 is the prefabricated section of the tie beam cavity; 6 is the cast-in-place hanger of the joint section; 7 is the joint section of the tie beam; 8 is the cofferdam steel pipe pile after cutting. DETAILED DESCRIPTION

[0010] The present invention will be further described in detail below in conjunction with the embodiments and with reference to the accompanying drawings.

[0011] A construction method for a deepwater large-span tie beam, the specific construction steps are as follows: A. Construct two cap cofferdams 3 at the same pier position, and cast the cap 1 and the pier body 2 in each cap cofferdam 3; B. constructing a cofferdam inner tie beam section 4 on each of the upper inner walls of the two pier bodies 2; C. Synchronously prefabricate the tie beam cavity prefabricated section 5 on an open space outside the site; D. After the pier body 2 is out of water, the steel pipe piles of the cap cofferdam within the range of the tie beam are cut underwater to the bottom elevation of the tie beam to obtain the cofferdam steel pipe piles 8 after cutting; E. Integrally hoist the prefabricated cavity section 5 of the tie beam to the top of the steel pipe pile 8 of the cofferdam after cutting, between the two cast inner tie beam sections 4 of the cofferdam, pump out water in the cap cofferdam 3, and stop the water; F. Install the cast-in-place hanger 6 for the joint section at the joint range between the two ends of the prefabricated tie beam cavity prefabricated section 5 and the cast cofferdam inner tie beam section 4; G. Casting concrete of the tie beam closure section 7 on the cast-in-place hanger 6 of the closure section; H. pouring concrete in the cavity of the tie beam cavity precast section 5; I. When the concrete in the cavity of the tie beam joint section 7 and the tie beam cavity prefabricated section 5 reaches the designed strength, the cast-in-place hanger 6 of the joint section and the cap cofferdam 3 are removed to obtain a deep-water large-span tie beam.

[0012] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to the present invention are within the scope of protection.

[0013] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A construction method for a deepwater large-span tie beam, characterized in that: The specific construction steps are as follows: A. Construct two cap cofferdams at the same pier location, and cast the cap and pier body in each cap cofferdam; B. Construct a cofferdam inner tie beam section on each of the upper inner walls of the two piers; C. Synchronously prefabricate the tie beam cavity prefabricated sections on an open space outside the site; D. After the pier body is out of water, the steel pipe piles of the cap cofferdam within the range of the tie beam are cut underwater to the bottom elevation of the tie beam to obtain the steel pipe piles of the cofferdam after cutting; E. Integrally hoist the prefabricated hollow section of the tie beam to the top of the steel pipe pile of the cofferdam after cutting, between the two cast inner tie beam sections of the cofferdam, pump out water in the cap cofferdam, and stop the water; F. Install cast-in-place hangers for the joint sections at the joint range between the two ends of the prefabricated tie beam cavity prefabricated section and the cast cofferdam inner tie beam section; G. Pour the concrete of the tie beam closure section on the cast-in-place hanger of the closure section; H. pouring concrete in the cavity of the precast section of the tie beam cavity; I. When the concrete in the cavity of the tie beam joint section and the precast section of the tie beam cavity reaches the designed strength, remove the cast-in-place hangers and the pedestal cofferdam of the joint section to obtain the deep-water large-span tie beam.

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