Construction method for bridging and crossing expansion joint of large-span reticulated shell structure

Abstract

The invention relates to a construction method for bridging and crossing an expansion joint of a large-span reticulated shell structure. The construction method comprises the steps of installation of the large-span reticulated shell structure and installation of the expansion joint. The large-span reticulated shell structure comprises a left reticulated shell structure and a right reticulated shell structure which are adjacent to each other, and the expansion joint is arranged between the left reticulated shell structure and the right reticulated shell structure; each of the left reticulated shell structure and the right reticulated shell structure comprises a reticulated shell unit structure formed by connecting an upper chord member, a lower chord member and a web member through a bolt ball; the construction method has the advantages of being reasonable in structural design, convenient to operate and use, safe, reliable and the like, the construction step that a starting frame needs to be hoisted for multiple times for a latticed shell structure is omitted by adopting the unique construction process that temporary rod pieces are adopted for bridging transition at the expansion joints, construction safety, efficiency and economical efficiency are improved, and the construction cost is reduced. The starting frame can be suitable for building or structure construction projects of a large-span reticulated shell structure which needs to be hoisted for multiple times.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a construction method for bridging a large-span lattice shell structure across an expansion joint. Background Art

[0002] With the acceleration of urbanization and the rapid development of the construction industry, the requirements for construction technology are becoming higher and higher. Especially in the grid shell structure project, the span and longitudinal length of the grid are gradually increasing. Because of the existence of thermal expansion and contraction, when the length of a single-section grid reaches the specification, the continuous grid rods must be disconnected and expansion joints must be set to deal with the temperature effect. For the construction of the grid shell structure, we usually adopt a combination of large assembly of the starting frame and small assembly of small components at high altitude. Then, each expansion joint means a large assembly of the starting frame. When facing a long and deep large-span grid shell structure, there will be multiple starting hoisting construction processes. This process is the process of splicing the frame from movable components into a stable spatial structure, which has a great construction safety risk. It is necessary not only to verify the internal force distribution after the completion of the starting frame, but also to verify the internal force of the grid during the construction process. At the same time, it is necessary to coordinate the cooperation between large machinery. Specifically, the existing gridshell structure construction technology: conventionally adopts the method of large assembly of the starting frame + small assembly of small components at high altitude (the starting frame usually refers to: the rods within the span range of the three continuous longitudinal axes of the building are connected to form a stable spatial structure), and the detailed process flow is: construction preparation → laying out and positioning → setting up temporary supports → placing adjustable supports and lower chord balls → adjusting the elevation of the lower chord balls → assembling the lower chord → assembling the upper chord and tightening the web bars → correcting the small unit grid → hoisting the starting grid → correction → welding of the support → intermediate acceptance → bulk assembly of most grids at high altitude → tightening → correction of small unit grids → welding of supports → intermediate acceptance → touch-up painting → final acceptance. Because of the existence of expansion joints, each section of the grid needs to be constructed according to the above process. Due to the aforementioned reasons, large assembly of the starting frame is a process with great safety hazards, and ways should be found to reduce this process. In the actual construction process, when the span of the grid is greater than 60m, it falls within the scope of "sub-projects exceeding a certain scale with greater risks" as stipulated in Document No. 31 of the Ministry of Housing and Urban-Rural Development, and experts should be invited to demonstrate the feasibility of the construction plan. Therefore, the research and development and application of more advanced, efficient, safe and reliable construction technologies have become an important direction for the development of the industry. The construction technology of large-span grid shell structure bridges across expansion joints came into being under such a background, but the existing large-span grid shell structure expansion joint construction still has room for improvement, such as unreasonable structural design and cumbersome operation. The present invention is proposed based on the above research background, and aims to provide a construction method of large-span grid shell structure bridges across expansion joints, so as to solve the above technical problems and meet the actual use needs. Summary of the invention

[0003] In view of the above background technology, the purpose of the present invention is to provide a construction method for building a bridge for a large-span lattice shell structure to cross an expansion joint, which has the advantages of reasonable structural design, easy operation and use, safety and reliability, etc. By adopting a unique construction process of using temporary rods to build a bridge transition at the expansion joint, the construction steps of the lattice shell structure that require multiple hoisting of the starting frame are solved, and the safety, efficiency and economy of the construction are improved. The present invention can be applied to building or structural construction projects in which a large-span lattice shell structure requires multiple hoisting of the starting frame.

[0004] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0005] A construction method for a large-span lattice shell structure to bridge across an expansion joint, the construction method comprising the steps of installing the large-span lattice shell structure and installing the expansion joint; wherein:

[0006] The large-span lattice shell structure comprises two adjacent left lattice shell structures and a right lattice shell structure, and the expansion joint is arranged between the left lattice shell structure and the right lattice shell structure; the left lattice shell structure and the right lattice shell structure each comprise a lattice shell unit structure formed by connecting an upper chord, a lower chord and a web member through a bolt ball;

[0007] The installation steps of the left lattice shell structure and the right lattice shell structure are the same, and both include the following steps:

[0008] 11) On both sides of the ground, the starting space structure is formed by laying down and assembling the starting grid shell modules. When the length of the grid shell is such that one end is on the support and the other end falls naturally, the next step can be entered;

[0009] 12) Use a 50-ton truck crane to lift the left and right starting space lattice shell structures in step 1) respectively, and seat each starting space lattice shell structure on one end of the support at the corresponding position, and let the other end fall naturally. After the seating is completed, proceed to the next step;

[0010] 13) Use a 50-ton truck crane to lift one end, move the lifting point, and expand the starting lattice shell space structure on the left and right sides to form a bulk lattice shell structure. When the lattice shell is expanded to this section, proceed to the next step;

[0011] 14) Assemble the middle section lattice shell structure at the nearest ground position, and proceed to the next step after the middle section lattice shell is assembled;

[0012] 15) Use a truck crane to lift the left and right side lattice shells to the designed height respectively, and use another 180-ton truck crane to lift the middle section lattice shell to the designed position, and butt-join it with the left and right side lattice shells. After the butt-joining meets the construction requirements, proceed to the next step;

[0013] 16) After the three sections of the starting grid shell are joined together, the grid shell is adjusted and corrected, the support and embedded parts are welded and fixed in place according to the design requirements, and the wire rope and crane hook are removed; the starting grid shell is completed and enters the next step of high-altitude loose assembly. In this stage, small rod units are assembled on the ground, lifted to high altitude, and then expanded and assembled to the grid shell by high-altitude workers. By repeating this step, the grid shell of the entire construction section can be assembled;

[0014] The installation steps of the expansion joint include:

[0015] 21) Select a small section of lattice shell unit body, expand and assemble from the support to the mid-span, and complete 5-6 grids to form a small section of spatial structure before proceeding to the next step;

[0016] 22) Lift the small section of the grid shell to the designed position, and use another machine to lift the transition rod to the same height, and connect the transition rod between the small section of the grid shell and the completed grid shell. At this time, the small section of the grid shell is a stable spatial structure, and the upper and lower transition rods are tension-compression rod models. The upper transition rod is tensioned and the lower transition rod is compressed to withstand the roll effect caused by the deadweight of the small section of the grid shell, and then continue to expand to the middle of the grid shell span until the connection is successfully made in the middle of the grid shell span to proceed to the next step;

[0017] 23) Relying on the stable unit body formed in the previous step 22), continue to expand along the longitudinal direction of the lattice shell until the extended length is the same as the longitudinal length of the starting lattice shell, it can be considered that the assembly of this section of the lattice shell structure is completed, and the starting lattice shell is subjected to force alone, and then proceed to the next step;

[0018] 24) Use cutting tools to remove the transition rods, and the lattice shell continues to expand and extend until it encounters an expansion joint and repeats the above steps, or until the entire lattice shell is completed.

[0019] As a further optimization of the above solution, an expansion joint is set every 120m in the long-span lattice shell structure.

[0020] The construction method of the present invention for bridging a large-span lattice shell structure across an expansion joint has the following beneficial effects:

[0021] 1. Improve construction efficiency: By simplifying the construction process and reducing construction risks, the present invention can significantly improve the construction efficiency of the lattice shell structure, which not only helps to shorten the project period, but also helps to improve the project quality.

[0022] 2. Reduce construction costs: By reducing the ground assembly and hoisting operations of the starting frame and using reusable temporary transition rods, the present invention can significantly reduce construction costs, which is of great significance for improving the economic benefits of the project.

[0023] 3. Improve construction safety: The temporary transition rod design of the present invention avoids high-risk starting frame hoisting operations, reduces construction risks, improves construction safety, and can well protect the lives and property of construction workers.

[0024] 4. Promote technological innovation: The proposal and application of this invention not only solves the problems existing in traditional construction technology, but also brings new technological innovation ideas to the field of steel structure grid construction, which will help promote technological progress and development in this field. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Attached Figure 1 The diagrams are schematic diagrams of the structures of the left and right lattice shell structures of the present invention, wherein (a) is a schematic diagram of the installation of the starting space lattice shell structure, (b) is a schematic diagram of the installation of the bulk lattice shell structure, (c) is a schematic diagram of the installation of the high-altitude scattered assembly, and (d) is a schematic diagram of the installation of the left and right lattice shells being butted together.

[0026] Attached Figure 2 This is a schematic diagram of the structure of the rod unit in step 16) of the present invention.

[0027] Attached Figure 3 It is a structural schematic diagram of the upper and lower transition rods of the present invention. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1-3 The invention provides a construction method for a large-span lattice shell structure to bridge across an expansion joint.

[0029] A construction method for a large-span lattice shell structure to bridge across an expansion joint, the construction method comprising the steps of installing the large-span lattice shell structure and installing the expansion joint; wherein:

[0030] The large-span lattice shell structure comprises two adjacent left lattice shell structures and a right lattice shell structure, and the expansion joint is arranged between the left lattice shell structure and the right lattice shell structure; the left lattice shell structure and the right lattice shell structure each comprise a lattice shell unit structure formed by connecting an upper chord, a lower chord and a web member through a bolt ball;

[0031] The installation steps of the left lattice shell structure and the right lattice shell structure are the same, and both include the following steps:

[0032] 11) On both sides of the ground, the starting space structures 1 and 2 are formed by laying down and assembling the starting lattice shell modules. When the length of the lattice shell is such that one end is on the support and the other end falls naturally, the next step can be entered;

[0033] 12) Use a 50-ton truck crane to lift the left and right starting space lattice shell structures in step 1) respectively, and seat each starting space lattice shell structure on one end of the support at the corresponding position, and let the other end fall naturally. After the seating is completed, proceed to the next step;

[0034] 13) Use a 50-ton truck crane to lift one end, move the lifting point, and expand the starting lattice shell space structure on the left and right sides to form a bulk lattice shell structure 3. When the lattice shell is expanded to this section, the next step can be entered;

[0035] 14) Assemble the middle section lattice shell structure 4 at the nearest ground position, and proceed to the next step after the middle section lattice shell is assembled;

[0036] 15) Use a truck crane to lift the left and right side lattice shells to the designed height respectively, and use another 180-ton truck crane to lift the middle section lattice shell to the designed position, and butt-join it with the left and right side lattice shells. After the butt-joining meets the construction requirements, proceed to the next step;

[0037] 16) After the three sections of the starting grid shell are joined together, the grid shell is adjusted and corrected, the support and the embedded parts are welded and fixed in place according to the design requirements, and the wire rope and the crane hook are removed; the starting grid shell is completed, and the next step of high-altitude loose assembly is entered. In this stage, the small rod unit 5 is assembled on the ground, lifted to a high altitude, and then expanded and assembled to the grid shell by the high-altitude workers. By repeating this step, the grid shell of the entire construction section can be assembled;

[0038] The installation steps of the expansion joint include:

[0039] 21) Select a small section of lattice shell unit body, expand and assemble from the support to the mid-span, and complete 5-6 grids to form a small section of spatial structure before proceeding to the next step;

[0040] 22) Lift the small section of the grid shell to the designed position, and use another machine to lift the transition rod to the same height, and connect the transition rod between the small section of the grid shell and the completed grid shell. At this time, the small section of the grid shell is a stable spatial structure, and the upper and lower transition rods are tension-compression rod models. The upper transition rod 6 is tensioned and the lower transition rod 7 is compressed to withstand the roll effect caused by the deadweight of the small section of the grid shell, and then continue to expand to the middle of the grid shell span until the connection is successfully made in the middle of the grid shell span, and then proceed to the next step;

[0041] 23) Relying on the stable unit body formed in the previous step 22), continue to expand along the longitudinal direction of the lattice shell until the extended length is the same as the longitudinal length of the starting lattice shell, it can be considered that the assembly of this section of the lattice shell structure is completed, and the starting lattice shell is subjected to force alone, and then proceed to the next step;

[0042] 24) Use cutting tools to remove the transition rods, and the lattice shell continues to expand and extend until it encounters an expansion joint and repeats the above steps, or until the entire lattice shell is completed.

[0043] Due to the existence of temperature effect, with the repeated accumulation of rods and the continuous extension of the longitudinal length of the lattice shell, the lattice shell rods will be subjected to increasingly greater temperature stress. Therefore, expansion joints are set every 120m in the long-span lattice shell structure.

[0044] The above description of the implementation cases is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the embodiments herein, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A construction method for bridging a large-span lattice shell structure across an expansion joint, characterized in that: The construction method includes the steps of installing a large-span lattice shell structure and installing an expansion joint; wherein: The large-span lattice shell structure comprises two adjacent left lattice shell structures and a right lattice shell structure, and the expansion joint is arranged between the left lattice shell structure and the right lattice shell structure; the left lattice shell structure and the right lattice shell structure each comprise a lattice shell unit structure formed by connecting an upper chord, a lower chord and a web member through a bolt ball; The installation steps of the left lattice shell structure and the right lattice shell structure are the same, and both include the following steps: 11) On both sides of the ground, the starting space structures 1 and 2 are formed by laying down and assembling the starting lattice shell modules. When the length of the lattice shell is such that one end is on the support and the other end falls naturally, the next step can be entered; 12) Use a 50-ton truck crane to lift the left and right starting space lattice shell structures in step 1) respectively, and seat each starting space lattice shell structure on one end of the support at the corresponding position, and let the other end fall naturally. After the seating is completed, proceed to the next step; 13) Use a 50-ton truck crane to lift one end, move the lifting point, and expand the starting lattice shell space structure on the left and right sides to form a bulk lattice shell structure 3. When the lattice shell is expanded to this section, the next step can be entered; 14) Assemble the middle section lattice shell structure 4 at the nearest ground position, and proceed to the next step after the middle section lattice shell is assembled; 15) Use a truck crane to lift the left and right side lattice shells to the designed height respectively, and use another 180-ton truck crane to lift the middle section lattice shell to the designed position, and butt-join it with the left and right side lattice shells. After the butt-joining meets the construction requirements, proceed to the next step; 16) After the three sections of the starting grid shell are joined together, the grid shell is adjusted and corrected, the support and the embedded parts are welded and fixed in place according to the design requirements, and the wire rope and the crane hook are removed; the starting grid shell is completed, and the next step of high-altitude loose assembly is entered. In this stage, the small rod unit 5 is assembled on the ground, lifted to a high altitude, and then expanded and assembled to the grid shell by the high-altitude workers. By repeating this step, the grid shell of the entire construction section can be assembled; The installation steps of the expansion joint include: 21) Select a small section of lattice shell unit body, expand and assemble from the support to the mid-span, and complete 5-6 grids to form a small section of spatial structure before proceeding to the next step; 22) Lift the small section of the grid shell to the designed position, and use another machine to lift the transition rod to the same height, and connect the transition rod between the small section of the grid shell and the completed grid shell. At this time, the small section of the grid shell is a stable spatial structure, and the upper and lower transition rods are tension-compression rod models. The upper transition rod 6 is tensioned and the lower transition rod 7 is compressed to withstand the roll effect caused by the deadweight of the small section of the grid shell, and then continue to expand to the middle of the grid shell span until the connection is successfully made in the middle of the grid shell span, and then proceed to the next step; 23) Relying on the stable unit body formed in the previous step 22), continue to expand along the longitudinal direction of the lattice shell until the extended length is the same as the longitudinal length of the starting lattice shell, it can be considered that the assembly of this section of the lattice shell structure is completed, and the starting lattice shell is subjected to force alone, and then proceed to the next step; 24) Use cutting tools to cut off the transition rods, and the lattice shell continues to expand and extend until it encounters an expansion joint and repeats the above steps, or until the entire lattice shell is completed.

2. The construction method of a large-span lattice shell structure for bridging across an expansion joint according to claim 1, characterized in that: Expansion joints are set every 120m in the long-span lattice shell structure.

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