The tallest building in Asia, Shenzhen Diwang Commercial Building, built by our bureau, was capped ahead of schedule in June 1995 with the care and support of leaders from all walks of life and leaders at all levels. This is not only the pride of China Construction Third Engineering Bureau, but also the common pride of construction colleagues on both sides of the Taiwan Strait. It marks a major breakthrough in my country's construction of high-rise, especially super-high-rise steel structures.
1. "The Glorious Course"; Review of the Construction History of Super High-Rise Steel Structures of Our Bureau
Compared with developed countries, super-high-rise steel structure buildings started late in our country and are mature and There is not much experience to draw from. Since the reform and opening up, many "tall, big, new and cutting-edge" modern buildings have sprung up like mushrooms after a rain, becoming an important symbol of the rapid development of the national economy. Steel structures are widely used in high-rise, especially super-high-rise buildings due to their advantages and characteristics such as light weight, short construction period, and strong earthquake resistance. With its corporate spirit of "dare to be the first in the world and strive to be the first-class" and its courage and strength to undertake "high, large, new and cutting-edge" projects, China Construction Third Engineering Bureau has aimed at this fertile soil that has yet to be cultivated and exerted its efforts. With the technology and equipment advantages of large enterprises, it took the lead in constructing the first super high-rise steel structure building in Quantong in 1986; the 165.3m-tall Shenzhen Development Center Building completed the main 11,000-ton steel structure construction task in just 10 months. , the maximum vertical deviation is 25mm, which raises the standard of the American AISC standard. It is the first to use the new process of CO2 gas shielded semi-automatic welding for ultra-thick steel plate welding. After hard study and repeated research, it finally successfully solved the welding of 130mm ultra-thick steel plate. technology. It fills the gap in the welding of ultra-thick steel plates in the factory. The welding quality of the entire project is 100% ultrasonic flaw detection, 100% qualified, and has reached the international first-class level. The successful application of the complete set of construction technology of this project has brought a big step forward for the installation and construction technology of super high-rise steel structures that started late in my country. The complete set of installation technology of the steel structure of the Shenzhen Development Center Building won the Mid-term Award in 1988 and 1989 respectively. The first prize for the scientific and technological progress of the company and the third prize for the national scientific and technological progress.
Due to its great success in the installation of the ultra-high-rise steel structure of the Shenzhen Development Center Building, in 1987 it won the bid to build my country's first all-steel ultra-tall building, the 146.5-meter-tall Shanghai International Trade Center Building. , the construction task of the main 10,470-ton steel structure was completed in a "safe, high-quality, high-speed" construction period of only 7.5 months. The verticality deviation of the main body of the steel structure is only 17mm. It has improved the Japanese JASS standard, and the welding is 100% flaw-detected and 100% qualified. It has been highly praised by the owners and all walks of life. The project won the highest construction quality award in Shanghai; the "Magnolia" award and the national The highest award in the construction industry; Luban Golden Statue Award. Since then, we have undertaken the construction of steel structure projects with high reputation in China such as Shanghai Taiping Hotel, New Jinqiao Building and ① Jie Plaza, especially the 383.95m-high Shenzhen Diwang Building which was topped out on June 9, 1995. Our company It only took 1 year and 12 days (more than two months ahead of the contract period) to complete the construction task of the 24,500-ton steel structure of the main building safely, with high quality and at high speed. The total vertical deviation of the main body was 17mm outward and 25mm inward, which improved The accuracy is only 1/3 of the allowable error of the American AISC specification (51mm outward, 76mm inward); the weld extension meter is 600,000 meters (vertical welding and oblique vertical welding account for 1/7), 100% flaw detection, 100% qualified , the excellent rate reached 94%, and created the miracle of no components falling, no casualties during the entire construction process, and the 90th "Shenzhen New Speed" of one floor in two and a half days. The rare construction period, first-class quality and safety
have been highly praised by owners, general contractors and all walks of life.
In August last year, the installation and construction technology of the ultra-high-rise steel structure of the main building of Shenzhen Diwang Building passed the national appraisal. Experts attending the meeting agreed that the Diwang Building is a representative work of the ultra-high-rise steel structure project that has only started in my country in the past decade, indicating that my country's high-rise steel structure construction technology has made significant progress based on past successes. The Diwang Tower's ultra-high-rise steel structure The installation and construction technology has reached the leading domestic and international levels.
From Shenzhen Development Center to Shangyang International Trade Center, and from Shanghai International Trade Center to Shenzhen Diwang Building, they are milestones in the history of the development of super-high-rise steel structure installation in my country and from weak to strong construction technology. They represent a milestone. The glorious history of the Third Bureau in the development history of super high-rise steel structures in the past ten years.
2. Super high-rise steel structure self-assembly construction technology
Because I was fortunate enough to participate in three major super high-rise steel structure projects that are of epoch-making significance in the history of steel structure development in my country: Shenzhen Development The construction organization and management of the Central Building, Shanghai International Trade Center and Shenzhen Diwang Commercial Building are combined with the technological process and characteristics of high-rise steel structures: (component acceptance → hoisting → quantity control → high-strength bolts → welding and testing → profiled steel plates and welded studs). The installation and construction technology of super high-rise steel structures is mainly reflected in the following seven aspects:
1. Arrival, acceptance and stacking of components
2. Selection, layout, installation and disassembly of tower cranes
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3. Hoisting
4. Measurement control
5. Welding
6. Construction period and quality control
7 , safe construction
Now, based on the construction situation of the super high-rise steel structure of the main building of Shenzhen Diwang Building, I will share with experts and colleagues the experience and understanding of the construction of super-high-rise steel structures on these issues.
1. Access, acceptance and stacking of components
Small space and poor construction conditions are common difficulties in current construction projects. For higher-rise steel structure projects, it is relatively tense. The requirements for the component yard during the construction period are higher and stricter. If this problem is not handled well, it will have a serious impact on the hoisting and the entire project construction. In the early stage of construction of the Diwang Building, due to the large number of components in the storage yard and the large amount of steel structures entering the site, 2-3 layers need to be stacked. Without a careful approach plan, it will inevitably lead to confusion in the order of the components entering the site. The result is: it is necessary to The components are pressed below and the unused components are placed on top. Not only the acceptance work cannot be carried out, but also there is a lot of repetitive work such as turning over and looking for materials. Later, on the basis of strengthening on-site management and component access plan, we focused on the layout of the storage yard and the stacking sequence of components. In addition to the careful access components required for hoisting, we also focused on the hoisting sequence and the characteristics of the storage yard planning. The field components are arranged in an orderly manner, which not only ensures the normal progress of the acceptance work, but also creates good external conditions for hoisting.
It is our experience and understanding in the past construction of super high-rise steel structure projects to ensure the acceptance of components. There are 14,860 steel components in the main building of Shenzhen Diwang Building. Problems of one kind or another will inevitably occur during the manufacturing and transportation process. If these problems are not eliminated on the ground, hoisting them above will inevitably increase the installation progress and control the quality of the entire work. It will also have serious consequences.
2. Selection, arrangement, installation and disassembly of tower crane
Tower crane is the core equipment for the construction of super high-rise steel structure projects. Its selection and arrangement should be based on the layout of the building, site conditions and The weight of the steel structure and other factors should be taken into consideration to ensure the safety, convenience and reliability of assembly and disassembly.
We selected two Australian-made steel pipes based on the geographical location, structural shape and large number of special components of the Diwang Building (such as the large "A" inclined column weighing 47.5t and the box column weighing 37t/section). The M440D large internal climbing tower crane is arranged in the core wall #1 and #5 shafts, which not only meets the vertical transportation of all components, but also creates conditions for dual-machine lifting of a large number of overweight, ultra-height and eccentric components.
This is the first time that the M440 internal climbing tower crane has been used in China, and there is not much mature experience to learn from. During the construction, we changed the traditional climbing scheme of tower cranes hoisting each other and adopted a "winch + shoulder pole" auxiliary system to better solve the climbing problem of the two tower cranes, greatly improve the efficiency of the tower crane and speed up the lifting speed. It played a decisive role in advancing the construction period; and the dismantling of a large internal climbing tower crane is a technically complex and difficult construction task. We adopted the method of "reducing the large to the small and breaking the whole into parts" to better solve the problem in The demolition problem of large-scale internal climbing tower cranes, which is regarded as a difficult problem in China, provides an example for the use of internal climbing tower cranes in similar domestic projects.
3. Hoisting
Hoisting is the leading process in steel structure construction. The speed and quality of hoisting play a decisive role in the entire project. In the construction of the main super high-rise steel structure of the Diwang Building in Shenzhen, the contradiction between the tight construction schedule and the large amount of work was solved by adopting "regional hoisting" and "one machine with multiple hoisting" technologies.
The use of "dual-machine lifting" and gantry not only solves the lifting problem of the large "A" inclined crane with a height of 53.79m, a length of 63.20m, a span of 32.1m, and a weight of 232t, but also It solves the problem of hoisting two large masts on the main building that are 85.61m long, weigh 85.51t and are in an overweight, eccentric and ultra-high state.
4. Measurement control
In the construction of super high-rise steel structures, verticality, axis and elevation deviations are important indicators for measuring project quality. Measurement is the control stage of project quality. Must provide a basis for construction inspection.
It can be seen from the steel structure construction process that the various processes are both interconnected and restrictive. The choice of measurement control method directly affects the progress and measurement of the project. In the early stages of the steel structure construction of the Diwang Building in Shenzhen, the surveying and supervision engineer of the general contracting unit proposed the method of "overall correction", that is, tracking and correcting the deviation after the columns were installed. When the beams could not be installed, they were temporarily hung or placed on them. Columns, beams, and diagonal braces are all installed before overall correction. Since there are certain errors in the production of components and core construction, the use of this correction method is very blind. Not only does it cause a large number of secondary installations, but the structure itself already has a certain stiffness after the columns and beams are installed, which greatly increases the the difficulty of correction. Later, we promptly changed the "overall correction" to "tracking correction", that is, the columns were initially corrected and corrected in time before the column-beam frame was formed, which greatly reduced the difficulty of correction. The correction time of each section was shortened from about 10 days to 2-3 days. It can be handed over to the next process operation, and the goal of a virtuous cycle between the various processes of regional construction is achieved.
In order to make the steel structure construction of the main building of Diwang Building reach the world-class level, the project also formulated quality control indicators that are stricter than the American AISC standards: 25mm inwards and 20mm outwards, and developed a complete set of laser The new method of "dual system review control" was discussed directly, which played a very important role in ensuring that the project quality control objectives were achieved.
5. Welding
High-rise steel structures have the characteristics of tight construction schedule, complex structure, large amount of work, and high quality requirements. As an important process of steel structure construction, welding has The selection and welding level have a significant impact on the "safe, high-quality, high-speed" completion of the project.
Shenzhen Diwang Building has a rare height-to-width ratio of 1:9, so a large number of diagonal braces and large "A" diagonal columns were used in the design. Among the total 600,000 meters of extended joints, there are approximately 86,000 meters of vertical and oblique vertical welding, and a total of 848 sets of joints, accounting for 1/7 of the entire welding project. This type of structure is not only an important part of the structure, but also Most of them are in outward, diagonal and suspended positions, making safe operation and construction protection difficult. In particular, the contradiction between the relatively tight construction period and the huge amount of welding work caused us to face a severe test from the beginning. Although in the construction of steel structure projects such as Shenzhen Development Center Building and Shanghai International Trade Center Building, we use CO2 gas shielded semi-automatic welding for vertical welding, oblique vertical welding and dip angle welding, which can fundamentally solve the needs of welding construction.
After the process is selected, it becomes a top priority to compile a set of feasible CO2 gas shielded semi-automatic welding processes and methods suitable for the characteristics of this project. The welding QC team, led by the project team, made difficult attempts and carried out a series of fruitful work.
First of all, we determined the research goals, used correlation diagrams to find out the reasons that affected quality, and applied the 01 analysis method to conduct a series of analyses, to find corresponding countermeasures for these problems; and established effective quality assurance system, a complete process instruction book was formulated, and after repeated experiments, the process parameters used for vertical welding and oblique vertical welding were determined; through repeated exploration of the extension length of the welding wire, cleaning between weld seams, and welding angles, the formation of A set of operating essentials of "picking, pressing, dragging and turning" has been developed; in order to keep the welding environment in a relatively stable state, construction protective measures and auxiliary measures have been strengthened. Through the unremitting efforts of the project team and the welding QC team, after half a month of failure, summary, small results, large results, consolidation, and more mature, repeated welding tests, we finally successfully solved the problem of CO2 gas shielded welding. Welding process issues applied to vertical and oblique vertical welding heads of ultra-thick parts (national patent has been obtained). Through technical research and process improvement, the welding quality has been gradually improved, and the construction period has been greatly advanced. It has been well received by the general contractor and owners, has produced good social and economic benefits, and has created a good reputation in society.
6. Quality and construction schedule control
The distinctive features of super high-rise steel structures that are different from ordinary concrete buildings are: high quality and tight construction schedule. The guarantee of quality and construction period relies on scientific management, strict construction organization and bold application of new technologies, new processes and new equipment.
The main steel structure of Shenzhen Diwang Building consists of 14,860 pieces, weighing 24,500t, with 140,000 square meters of profiled steel plates, 500,000 sets of welded studs, and a total length of welds of 600,000 meters. However, the construction period specified by the owner is only 14.5 months, and the project is inspected and accepted according to American standards. The short construction period, large amount of work, and high construction difficulty are rare at home and abroad.
Establishing a scientific management organizational system and strictly following the project management method are the keys to ensuring that the project is carried out "safely, with high quality and at high speed". To this end, we have established the Diwang Project Management Department to implement the project manager responsibility system and full-staff contract management. In terms of organizational form, we implement fixed staffing, fixed positions, and fixed responsibilities, and advocate one person with multiple abilities, one person with multiple positions, and section leaders working together with workers on the front line. It not only sets an example but also facilitates on-site management. From the project manager to labor, safety, technology and other functional departments to work on-site, they can understand and grasp the progress of the project in a timely manner and solve related technical, quality, safety and other issues. The entire project management has formed a project manager-centered, integrated construction Organize a short and capable construction team integrating network security and quality assurance systems and new technology research and application and QC teams. At the same time, each construction section implemented project-day contracting, clarified responsibilities, rights, and benefits, and implemented a risk mortgage system, which maximized the enthusiasm and sense of responsibility of front-line workers and laid the foundation for the project to be completed quickly. In order to build the first world-class skyscraper built for the Chinese themselves into a cross-century classic, the project not only set quality control targets that were more stringent than American standards, but also actively cooperated with the lifting, measurement, and welding QC teams. In order to solve key problems, the "four new" technologies have been fully applied in the installation and construction of the super high-rise steel structure of the main building of Diwang Building. Under the leadership of the project, the hoisting QC team improved the traditional "one machine with multiple hoisting" and "dual machine hoisting" technologies, which greatly accelerated the hoisting progress; the measurement QC team improved the traditional "overall measurement" technology, Innovative "tracking measurement" and "dual system review control" technologies successfully controlled the total deviation of the main building's verticality to 17mm outward and 25mm inward, which is only 1/3 of the American standard. After arduous attempts, the welding QC team Finally, we successfully broke through the restricted area of ??CO2 gas shielded semi-automatic welding for vertical and oblique vertical welding. Not only did it improve work efficiency and ensure the construction period, but all welds were 100% inspected by an authoritative third party and 100% qualified, with an excellent and excellent rate of 100%. 94%.
In steel structure engineering, the laying of profiled steel plates is a process with a heavy workload and high risk. The speed of laying not only directly affects the progress of the project, but also undergoes hoisting speed correction, high-strength bolts and welding, etc. The construction safety of a series of processes has a serious impact. For this reason, we imported two internationally advanced Co. spot welding machines from Japan. They are not only easy to operate and short in time, but also have smooth and clean welding points, good quality, and work efficiency that is five times that of manual welding. Advanced equipment such as the Australian M44OD large-scale internal climbing crane, Japanese CO. gas shielded semi-automatic welding machine and welding nail machine introduced during the construction of the super high-rise steel structure of the main building of the Geotechnical Building will all play an important role in the construction of this project. .
7. Safe construction
Safe construction is an important part of steel structure construction. The construction of super high-rise steel structures is characterized by many high-altitude and suspended working points. During the construction of the Diwang Building, there were 500,000 high-strength bolts alone. Although these things are small, if they fall from a height of several hundred meters, the consequences can be imagined. In order to prevent safety accidents, the project established a safety supervision team, set up full-time safety officers, strictly managed, formulated thorough and complete safety production regulations, conducted regular safety education for employees, and established the idea of ??"safety first". On the basis of strict management, the project does not hesitate to spend a lot of manpower, material resources, and financial resources for strict protection. Adopting new technologies such as erecting double-layer safety nets and laying profiled steel plates in advance, it was possible to achieve the miracle of 379 days of construction of the main ultra-high-rise steel structure of the Diwang Building without any casualties or falling components. At the construction technology appraisal meeting for the ultra-high-rise steel structure of Shenzhen Digong Commercial Building organized by China Construction Corporation, experts reached the internationally advanced level for the construction technology of the ultra-high-rise steel structure of Diwang Commercial Building. This achievement has been rated as our Bureau’s Special Prize for Scientific and Technological Achievements. The first prize for China State Construction Engineering Corporation’s Scientific and Technological Progress Award and the third prize for the National Scientific and Technological Progress Award.
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