Construction method of multi-curved-surface arched cable-stayed bridge high tower

Abstract

The invention provides a multi-curved-surface arched cable-stayed bridge high tower construction method which comprises the following steps: (1) stiff skeleton construction, (2) steel bar construction: adopting a small-diameter vibrating rod to cooperate with vibration to ensure the concrete pouring quality of a main tower; (3) protection layer control: setting out steel bar positions in the middle and at the bottom of the main tower structural framework, welding stirrups, and controlling the steel bar positions in advance to ensure that steel bar protection layers in the middle and top opening positions of steel bars meet standard requirements; (4) template construction; (5) bracket construction and prestress construction; (6) cableway pipe construction; and (7) main tower crane arrangement. The adjustable construction platform is adopted, and cyclic utilization of the formwork and the platform is guaranteed; a deep-buried anchor construction technology is adopted, and an adjustable tension extension sleeve is combined for auxiliary construction.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and particularly to a construction method for a high tower of a multi-curved arch cable-stayed bridge. Background Art

[0002] China's construction technology has also been developing rapidly, and the corresponding high tower technology of bridges has also been continuously improving. Novel and unique high tower cable-stayed bridges not only meet people's aesthetic requirements but also help to save construction costs and achieve sustainable utilization. This patent application combines the current status of the construction of high tower cable-stayed bridges in China, finds out the difficulties and problems in construction, and further proposes effective improvement countermeasures to ensure the construction quality of high tower cable-stayed bridges, reduce unnecessary economic losses, and lay a solid foundation for the further development of engineering construction. Summary of the Invention

[0003] The technical problem solved by the present invention is to provide a construction method for a high tower of a multi-curved arch cable-stayed bridge to solve the problems raised in the above background art.

[0004] The technical problem solved by the present invention is achieved by adopting the following technical solutions: A construction method for a high tower of a multi-curved arch cable-stayed bridge, comprising the following steps:

[0005] Step (1). Construction of the stiffening skeleton. The skeleton is the top priority for controlling the alignment of the arched high tower. All cable ducts and steel bars are positioned relying on the skeleton. Prefabrication is carried out at the backfield and installation is carried out on-site. Based on the cross-section of the tower column, the outline of the skeleton is designed, the positioning of the steel bars is optimized, and the outline of the steel bars is made according to the outline of the skeleton to ensure the thickness of the steel bar protection layer.

[0006] Step (2). Steel bar construction. A small-diameter vibrating rod is used for vibration to ensure the quality of the main tower concrete pouring.

[0007] Step (3). Protection layer control. The positions of the steel bars are lofted at the middle and bottom of the main tower structure skeleton, stirrups are welded, and the positions of the steel bars are controlled in advance to ensure that the steel bar protection layers at the middle and top of the steel bars meet the specification requirements.

[0008] Step (4). Formwork construction. An adjustable construction platform is used for the outer construction platform, and laminated formwork is used for the inner formwork. The plane formwork is made into standard block formwork, and the external curve formwork is processed in sections.

[0009] Step (5). Support construction and prestress construction.

[0010] Step (6). During the construction of the cableway pipe, the skeleton construction positioning points are selected and remembered, and the relative position size is calculated according to the design data; the relative position of the cable pipe is laid out on the skeleton, and the rigid skeleton is marked; the cableway pipe is installed by a crane, and the surveying personnel use a steel tape measure and a distance meter to repeatedly check until the design position is met and then fix it with angle steel; the rigid skeleton cableway pipe is numbered and stacked in the middle span, side span and segment, and deformation of the rigid skeleton should be avoided during stacking;

[0011] Step (7). Arrangement of the main tower crane: two tower cranes are installed on the main tower, respectively on the upstream and downstream sides of the pedestal. The maximum lifting weight on the upstream side is 8t, and the boom length is 65m. The maximum lifting weight on the downstream side is 8t, and the boom length is 40m. The maximum lifting force at the boom end is 2.98t, and the maximum effective lifting height of the tower crane is 115m. The tower crane foundation is located outside the pedestal, and the tower body is attached to the side wall of the tower column.

[0012] Furthermore, in the step (3), a movable Ф8 steel mesh is arranged outside the main reinforcement and fixed to the main reinforcement with iron wire, and a C50 pad is tied to the mesh to ensure the thickness of the protective layer of the reinforcement.

[0013] Furthermore, in the construction of the support, four transverse supports are set up for the main tower, which are arranged at 42m, 59m, 74m and 87m from the bottom of the tower respectively. The transverse support is composed of 2 Ф820×10mm steel pipes, and the vertical support adopts Ф820×10mm steel pipe. A total of 6 vertical supports are set up, with a spacing of 4.5m in the transverse direction of the bridge and 5m in the longitudinal direction of the bridge. A Ⅰ36b I-beam combined base is set at the contact position between the vertical support and the steel box girder, and the base is welded to the steel box girder panel. The scissors support is made of [20 channel steel.

[0014] Furthermore, during the construction of the support, a 100×100×1.6cm steel plate is embedded inside the main tower at the cross brace position and welded to the cross brace steel pipe, and a reinforcing plate is welded between the steel pipe and the embedded plate; the cross brace is divided into sections at the vertical support position, and a reinforcing plate is set to connect the steel pipes.

[0015] Furthermore, the prestressed construction includes vertical prestressing, annular prestressing and beam prestressing. The vertical prestressing is constructed in sections and connected by connectors in the middle.

[0016] Furthermore, when sealing the anchor in the prestressed construction, a grouting joint pipe is first installed, and a layer of PVC pipe is placed on the outer sleeve of the grouting joint pipe to facilitate the disassembly of the grouting pipe. Then, concrete is directly used for anchor sealing in one step. After the grouting is completed, the joint pipe can be removed without the need for secondary anchor sealing.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention adopts an adjustable construction platform to ensure the recyclability of the formwork and the platform; adopts the deep-buried anchor construction technology and combines it with an adjustable tensioning extension sleeve to assist in construction. The self-anchored tower crane foundation reduces the construction of the tower crane foundation in water and reduces construction risks; the balanced bracing technology ensures the safety of the tower column during construction and reduces the self-stress of the tower column; uses steel plates to replace the cut-off steel bars and reserves construction space, which not only does not affect the construction period but also ensures the project quality; constructs vertical prestress in segments to reduce the impact on concrete construction due to too long prestressed segments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic flow chart of the method of the present invention.

[0019] Figure 2 It is a schematic cross-sectional view of the tower column of the present invention.

[0020] Figure 3 It is a schematic diagram of the steel bar arrangement of the present invention.

[0021] Figure 4 It is a schematic diagram of the construction formwork of the present invention.

[0022] Figure 5 It is a schematic diagram of the construction support of the present invention.

[0023] Figure 6 It is a schematic diagram of the main tower tower crane arrangement of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] In order to make the implementation means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below with reference to specific drawings. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two components.

[0025] As Figures 1 to 6 shown, a high tower construction method for a multi-curved arch cable-stayed bridge includes the following steps:

[0026] Step (1). Rigid frame construction. The rigid frame is the top priority for controlling the alignment of the arched high tower. All the cable ducts and steel bars are positioned relying on the rigid frame. The rigid frame is prefabricated at the back field and installed on site. Based on the cross-section of the tower column, the outline of the rigid frame is designed, and the positioning of the steel bars is optimized. Using the outline of the rigid frame as the positioning outline of the steel bars to ensure the thickness of the steel bar protection layer;

[0027] Step (2). During the steel bar construction, a small diameter vibrator is used to ensure the quality of the main tower concrete pouring. A movable Ф8 steel mesh is arranged on the outside of the main reinforcement and fixed to the main reinforcement with iron wire. At the same time, a C50 pad is tied to the mesh to ensure the thickness of the steel bar protection layer.

[0028] Step (3). Protective layer control: Locate the steel bar positions in the middle and bottom of the main tower structure frame, weld the stirrups, control the steel bar positions in advance, and ensure that the steel bar protective layer in the middle and top of the steel bar meets the specification requirements;

[0029] Step (4) template construction, the outer construction platform uses an adjustable construction platform, the inner template uses a laminated template, the flat template is made into a standard block template, and the external curve template is processed in sections;

[0030] Step (5). Support construction and prestressing construction; the prestressing construction includes vertical prestressing, annular prestressing and beam prestressing. The vertical prestressing is constructed by segmentation and connected by connectors. When sealing the anchor in the prestressing construction, the grouting joint pipe is first installed. A layer of PVC pipe is placed on the outer sleeve of the grouting joint pipe to facilitate the removal of the grouting pipe. Then, concrete is directly used for anchor sealing in one step. After the grouting is completed, the joint pipe can be removed without secondary anchor sealing. In the support construction, four transverse supports of the main tower are set, which are arranged at 42m, 59m, 74m and 87m from the bottom of the tower respectively. The transverse support is composed of 2 Ф820×10mm steel pipes. The vertical support adopts Ф820×10mm steel pipes. A total of 6 vertical supports are set, with a spacing of 4.5m in the transverse direction and 5m in the longitudinal direction. A Ⅰ36b I-beam combined base is set at the contact position between the vertical support and the steel box beam. The base is welded to the steel box beam panel, and the scissors support is made of [20 channel steel. During the support construction, a 100×100×1.6㎝ steel plate is embedded inside the main tower at the cross brace position and welded to the cross brace steel pipe. A reinforcing plate is welded between the steel pipe and the embedded plate. The cross brace is divided into sections at the vertical support position, and a reinforcing plate is installed at the steel pipe connection.

[0031] Step (6). During the construction of the cableway pipe, the skeleton construction positioning points are selected and remembered, and the relative position size is calculated according to the design data; the relative position of the cable pipe is laid out on the skeleton, and the rigid skeleton is marked; the cableway pipe is installed by a crane, and the surveying personnel use a steel tape measure and a distance meter to repeatedly check until the design position is met and then fix it with angle steel; the rigid skeleton cableway pipe is numbered and stacked in the middle span, side span and segment, and deformation of the rigid skeleton should be avoided during stacking;

[0032] Step (7). Tower crane layout for the main tower: Two tower cranes are installed on the upstream and downstream sides of the main tower on the pile cap respectively. The maximum lifting weight on the upstream side is 8t, the boom length is 65m, the maximum lifting weight on the downstream side is 8t, the boom length is 40m, the maximum lifting force at the boom tip is 2.98t, and the maximum effective lifting height of the tower crane is 115m. The tower crane foundation is located outside the pile cap, and the tower body is attached to the side wall of the tower column.

[0033] Establish a self-inspection, monitoring and supervision system to conduct all-round and whole-process monitoring of the on-site quality.

[0034] Strengthen the construction of its own quality assurance system, establish and improve the quality management organization and system, strengthen the quality awareness education of construction personnel, allocate sufficient and competent quality inspection personnel and test personnel, establish and enrich the testing instruments and equipment in the laboratory, clarify the quality responsibilities of personnel in each position, and implement the post responsibility system. For any specific process, assign specific personnel to specific positions with clear responsibilities, and establish a reward and punishment system for quality effects, and conduct rewards and punishments level by level according to responsibilities.

[0035] Organize technical personnel to carefully familiarize with and check the design drawings, and submit the discovered errors to the supervisor and the owner. Be familiar with and master the design intention, carefully organize the construction plan and organize the technical disclosure work before construction.

[0036] Maintain close contact with the supervisor, earnestly listen to their guiding opinions, obey the supervisor's decision, and avoid errors and accident losses.

[0037] Strengthen the quality awareness education, often organize learning of construction technical specifications and professional training, learn new experiences and new technologies in supervision management and operation, and continuously improve the professional qualities of quality inspection personnel.

[0038] Construct strictly in accordance with the relevant national laws, regulations, technical standards and technical specifications for highway engineering construction, and strictly perform the contract.

[0039] Strictly control the quality inspection of raw materials. Seriously do a good job in the bidding and procurement of materials, give full play to the testing function of the laboratory, and prevent unqualified materials from entering the construction site.

[0040] The above has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A construction method for the high tower of a multi-curved arch cable-stayed bridge, characterized in that: The following steps are involved: Step (1). Construction of rigid skeleton. The skeleton is the most important part of the linear control of the arched tower. All the cables, tubes and steel bars are positioned by the skeleton. The skeleton is prefabricated and installed on site. The skeleton profile is designed based on the cross section of the tower column. The steel bar positioning is optimized. The skeleton profile is used as the steel bar positioning profile to ensure the thickness of the steel bar protective layer. Step (2) steel bar construction, using a small diameter vibrator to ensure the quality of the main tower concrete pouring; Step (3). Protective layer control: Locate the steel bar positions in the middle and bottom of the main tower structure frame, weld the stirrups, control the steel bar positions in advance, and ensure that the steel bar protective layer in the middle and top of the steel bar meets the specification requirements; Step (4) template construction, the outer construction platform uses an adjustable construction platform, the inner template uses a laminated template, the flat template is made into a standard block template, and the external curve template is processed in sections; Step (5). Support construction and prestressing construction; Step (6). During the construction of the cableway pipe, the skeleton construction positioning points are selected and remembered, and the relative position size is calculated according to the design data; the relative position of the cable pipe is laid out on the skeleton, and the rigid skeleton is marked; the cableway pipe is installed by a crane, and the surveying personnel use a steel tape measure and a distance meter to repeatedly check until the design position is met and then fix it with angle steel; the rigid skeleton cableway pipe is numbered and stacked in the middle span, side span and segment, and deformation of the rigid skeleton should be avoided during stacking; Step (7). Arrangement of the main tower crane: two tower cranes are installed on the main tower, respectively on the upstream and downstream sides of the pedestal. The maximum lifting weight on the upstream side is 8t, and the boom length is 65m. The maximum lifting weight on the downstream side is 8t, and the boom length is 40m. The maximum lifting force at the boom end is 2.98t, and the maximum effective lifting height of the tower crane is 115m. The tower crane foundation is located outside the pedestal, and the tower body is attached to the side wall of the tower column.

2. The construction method of the high tower of a multi-curved arch cable-stayed bridge according to claim 1, characterized in that: In the step (3), a movable Ф8 steel mesh is arranged outside the main reinforcement and fixed to the main reinforcement with iron wire. At the same time, a C50 pad is tied to the mesh to ensure the thickness of the protective layer of the reinforcement.

3. The construction method for the high tower of a multi-curved arch cable-stayed bridge according to claim 1, wherein: During the support construction, four transverse supports are set up for the main tower, which are arranged at 42m, 59m, 74m and 87m from the bottom of the tower respectively. The transverse support is composed of 2 Ф820×10mm steel pipes. The vertical support adopts Ф820×10mm steel pipe. A total of 6 vertical supports are set up, with a spacing of 4.5m in the transverse direction and 5m in the longitudinal direction. A Ⅰ36b I-beam combined base is set at the contact position between the vertical support and the steel box girder. The base is welded to the steel box girder panel, and the scissors support is made of [20 channel steel.

4. The construction method for the high tower of a multi-curved arch cable-stayed bridge according to claim 3, characterized in that: During the construction of the support, a 100×100×1.6㎝ steel plate is embedded inside the main tower at the cross brace position and welded to the cross brace steel pipe, and a reinforcing plate is welded between the steel pipe and the embedded plate; the cross brace is divided into sections at the vertical support position, and a reinforcing plate is set at the steel pipe connection.

5. The construction method for the high tower of a multi-curved arch cable-stayed bridge according to claim 1, characterized in that: The prestressed construction includes vertical prestressing, annular prestressing and beam prestressing. The vertical prestressing is constructed in sections and connected by connectors in the middle.

6. The construction method for the high tower of a multi-curved arch cable-stayed bridge according to claim 1, characterized in that: During the prestressing construction, when sealing the anchor, first install the grouting joint pipe. A layer of PVC pipe is sleeved outside the grouting joint pipe to facilitate the disassembly of the grouting pipeline. Then directly use concrete to seal the anchor in one step. After the grouting is completed, the joint pipe can be removed, and there is no need for secondary sealing of the anchor.

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