Guangzhou is located in the subtropical monsoon oceanic climate zone, belongs to the southern part of the hot summer and warm winter areas, with long summer and sunshine time, and many typhoons, heavy rainfall, and heavy rainfall. Buildings have a long air conditioning time in summer, especially large public buildings, building energy consumption is huge, the implementation of green building concepts helps to save energy, create an excellent indoor environment, and guide the correct green energy-saving awareness.
As a large-scale urban infrastructure with tourism and cultural and leisure functions, Canton Tower is a landmark building in Guangzhou, and actively implements the concept of sustainable development in the field of architecture during the construction process, and has carried out a series of innovations and attempts in green buildings, energy conservation and environmental protection, and its engineering experience is worthy of reference for similar buildings.
1. Project overview
Guangzhou Tower is located at the intersection of the Pearl River landscape axis and the new central axis of the city in Guangzhou, across the river from Haixinsha Island, which held the opening and closing ceremonies of the 16th Asian Games, and was rated as one of the "New Eight Views of Yangcheng" in Guangzhou, the project began construction in November 2005, and was completed and put into operation in October 2010.
The height of Guangzhou Tower is 600m, of which the main tower is 450m high and the antenna mast is 150m high, which is a multi-functional comprehensive building with radio and television technology rooms, sightseeing and tourism, leisure and entertainment, exhibition and business. Guangzhou Tower integrates contemporary advanced engineering design and construction technology, and is the tallest tower in China among the domestic tourist towers that have been put into use.
The site of the project is a subtropical climate zone, the average temperature of the coldest month is 13.3 °C, the average temperature of the hottest day is 28.4 °C, the outdoor ventilation temperature is 31 °C in summer, the average relative humidity of the coldest month is 70%, the average relative humidity of the hottest month is 83%, and the dominant wind direction in summer is southeast wind. 2, the concept of green building 2.1 design features The composition of the Canton Tower is composed of two ellipses from the top and the bottom, the center of the circle is staggered, and the counterclockwise rotation is 135 degrees, which naturally forms the shape of the "slender waist" in the middle of the tower.
Due to the rotation, the curvature of the tower's shape changes, resulting in a spectacular effect of different shapes. The more open structure at the top of the tower produces a transparent effect for long-term viewing, which is conducive to sightseeing, while the denser sections of the building waist can provide a relatively private experience and make the force of the tower structure more reasonable.
Guangzhou tower antenna mast for steel structure, tower structure to steel bone concrete core as the axis, the outer barrel steel structure system by 24 steel columns, 46 steel rings and diagonal bracing cross composition, the formation of hollow, open unique structural form, effectively reduce the tower body of the building volume and tower structure to bear the wind load, the architectural shape fully reflects the structural beauty, no unnecessary decoration, fully embodies the perfect combination of architecture and structural design design design of the design idea, its structural system on resource consumption and environmental impact is small, The main structural materials are a large number of reusable high-strength steel and high-strength concrete that can effectively save materials, reflecting the concept of green environmental protection, as shown in Figure 1.
Figure 1 Schematic diagram of the structural system of Canton Tower
2.2 The basic situation of green building design
In the design, construction and operation of Guangzhou Tower, it always adheres to the principle of sustainable development, pays attention to building energy conservation, adopts new technologies, new equipment and new materials, attaches importance to environmental protection, realizes the green building concept of land saving, energy saving, water saving and material saving, and meets the requirements of two-star green buildings. In order to save land resources, Canton Tower pays full attention to the development and utilization of underground space, and creates a good natural ventilation and lighting environment by setting up lighting wells, lighting roofs and sunken courtyard design.
The green space rate of the Canton Tower Project is 54%, taking into account the local climate characteristics, multi-level configuration of Lingnan tree species and vegetation such as Kapok, creating a good outdoor environment of "house in trees, people in green". The facades of each floor of Canton Tower are Low-E coated semi-tempered hollow SGP laminated glass curtain walls, and their visible light transmittance reaches 59%. The use of low-reflection Low-E glass significantly reduces the light pollution of the curtain wall to the environment and reduces indoor energy consumption.
In terms of indoor air treatment, in addition to conventional air treatment methods, air treatment units can more effectively filter air and degrade indoor organic pollutants by setting up electrostatic filtration devices and phototactase air purification devices. For the functional room where people gather, a return air carbon dioxide concentration sensor is set up, and the fresh air electric valve is automatically adjusted according to the return air carbon dioxide concentration to achieve the control of the fresh air volume.
Indoor noise control effectively reduces the operating noise of major equipment and effectively improves indoor comfort by setting up sound absorption layers, selecting low-noise equipment and setting vibration damping benches, floating shock absorbing floor slabs, spring shock absorbers, rubber shock absorbers, rubber shock absorber mats and other measures to reduce vibration, sound insulation and noise reduction. The air-conditioning equipment adopts an efficient cold and heat source unit, and the centrifugal chiller COP >5.20. The frequency conversion control of the double-sided pump of chilled water and cooling water greatly reduces the energy consumption of chilled water and cooling water transportation. The annual energy consumption of the cold and heat source system is more than 25% lower than that of the traditional system.
In the full air system of the tower with relatively large personnel density and large changes, fresh air demand control is adopted, and new air operation can be realized in the transition season of spring and autumn.
The exhaust heat recovery device is adopted to realize the exhaust heat recovery, and the molecular sieve type full heat exchange rotor heat recovery device is set up in the area of 84.8 meters to 460.8 meters to recover the energy in the exhaust system. The use of the above equipment and facilities effectively saves the energy consumption of the air conditioning system. The application of intelligent lighting energy-saving technology, the use of time automatic control, intelligent induction control and scene control three ways to efficiently control and manage the lighting of The Canton Tower.
Night lighting adopts LED energy-saving lamps, and the lighting mode is programmed and controlled according to different requirements such as major festivals, holidays, and dailys, which fully demonstrates the image of "landmark", saves energy and reduces consumption, and reduces operating costs. Strengthen the recycling of water resources, select water-saving equipment systems, use drip irrigation technology for greening, and pave grass boards, storage and drainage boards in platform squares, pedestrian roads, outdoor parking lots and slope protection green belts, etc., and can store about 5 liters of water per square meter. Set up a rainwater recycling system to collect rainwater from the second-floor platform square and treat it for the greening of the Canton Tower.
2.3 Renewable energy utilization
2.3.1 Photoelectric curtain wall power generation system
Translucent amorphous silicon BIPV PV modules with an installed capacity of 17.5kw were installed at an elevation of 438.4 meters to 448.8 meters, consisting of 346 translucent BIPV modules of 3100 × 1800 mm, as shown in Figure 2. According to statistics, the annual power generation of the photovoltaic system of this project is about 4900 degrees.
Figure 2 Real view of the photovoltaic curtain wall
2.3.2 The wind power generation system shall install two propeller wind turbines on the roof of Section C (at a height of 168 m), each with an installed capacity of 2.4Kw. According to statistics, the annual power generation capacity of each generator is about 1000 degrees. 3. Scientific research and design innovation Guangzhou Tower has applied a large number of innovative technologies in the project, reflecting the green building concept of low energy consumption, energy saving and environmental protection.
3.1 Vibration damping control system
Guangzhou Tower is equipped with the highest active and passive composite tuning mass damper (HMD) vibration control device in China, the installation height of the vibration control system of the main tower structure is 438.4 meters, and the installation height of the mast structure control system is 565.2 meters.
The main tower vibration reduction control system uses nearly 1200 tons of fire fighting pool as TMD quality, and installs an active control AMD control system at the top of the pool, which is technologically advanced and cost-effective, reflecting the characteristics of energy saving, high efficiency and environmental protection:
First, the tuning quality composed of 1200 tons of steel is saved;
The second is to save 2500 square meters of building space resources, save about 50 million yuan in construction costs, and also save corresponding building material resources;
Third, the vibration control system and the fire water tank are compatible to achieve the purpose of preventing wind, fire and earthquake disasters in the Canton Tower, and because the fire water tank is located at the top of the tower, it can ensure that 600 cubic meters of constant high-pressure fire water is used for fire extinguishing when a fire occurs.
Compared with the traditional passive control system, it not only improves the fatigue service life of the Guangzhou Tower wind vibration comfort and mast structure, improves the working environment of personnel and equipment, but also solves the fire water problem of super high-rise buildings, increases the reliability of structural safety and fire safety, and provides better reference value for ultra-high tower buildings.
3.2 Structural health monitoring system
Canton Tower is the world's first towering structure systematically installed with a structural health monitoring system, and is the world's first structural health monitoring system that organically combines structural construction monitoring with long-term operational health monitoring, and this technological achievement has won the Gold Medal and the Special Prize of the 37th International Exhibition of Invention and Innovative Technologies and Products in Geneva, Switzerland.
The Tower selects 5 key sections and installs more than 700 various sensors and equipment, which can monitor the environmental parameters, load action and structural reaction parameters of the Tower in real time, monitor the safety of the structure in real time, and provide first-hand data and information for the safe construction, operation and maintenance of the Tower. The technological innovation of the structural health monitoring system lies in the installation of a "24-hour Holter ECG scanner" on the main tower to monitor the structural safety of the Canton Tower in real time.
After the Canton Tower is put into operation, especially after the wind disaster and earthquake disaster, it is not necessary to use a lot of manpower and material resources to reinstall the structural monitoring and flaw detection equipment, so that the Guangzhou Tower can be diagnosed in real time whether structural damage occurs, the safety of the structure can be evaluated, the safety of the use is ensured, and the repeated investment of a large amount of manpower, material and financial resources is avoided, and resources are saved.
3.3 High-speed double car elevator
Canton Tower adopts a new type of "high-speed double-decker car elevator" that can connect two vertically moving cars to each other to meet the requirements of different floor heights. The unique telescopic instrument is used as a mechanism to connect and adjust the vertical distance between the upper and lower cars, which meets the requirements of the 2-meter difference in the height of the Guangzhou Tower.
Technological innovation of Guangzhou Tower high-speed double car elevator:
First, save building space resources, compared with the hydraulic drive up and down the car movement mode, the size of the outer car is smaller, greatly saving the shaft area, so that the net size of the car is expanded as much as possible, under the premise of the same shaft area, it increases the transport capacity of about 1.8 times, giving passengers a greater sense of car space, saving a total of about 3168m2 of the shaft area, saving 63 million yuan in construction costs, and also saving the corresponding building material resources;
The second is to save the number and energy consumption of elevator motors. The double car elevator saves the energy consumption of the car distance adjustment drive motor, and is equipped with an electric energy feedback device, which greatly improves the economic benefits of vertical elevator operation.
3.4 Tower and mast
The innovative bearing connection design mast steel column is directly connected with the core tube steel pipe column, the gravity of the antenna is directly transmitted to the core cylinder, and the bending moment is gradually transmitted from the inner cylinder to the outer cylinder, which realizes the weak conversion of the structure and is conducive to the seismic resistance of the structure; there is no stiffness mutation at the top of the tower. The impact on building functions, vertical transportation, equipment pipelines, etc. is small, and the construction difficulty is small; it can save about 200 tons of steel.
A new form is provided for the design of towering structures. In addition, in view of the complex structure of the Guangzhou Tower and the fact that the design exceeds the normative design basis, a series of scientific experiments and technological innovations such as basic wind pressure, seismic fortification standards, structural wind tunnel tests, seismic simulation shaker tests, outer cylinder column node tests and stability tests, fire safety performance evaluations, rock formation side friction resistance tests, etc., determine the key design basis beyond the design specifications, and optimize and improve the design, thereby ensuring the scientific and reliability of the new technology.
For example, the new rigid joint design of the outer cylinder and the space universal hinge node respectively solve the structural problems of the non-intersecting structural problems of the steel pipe concrete inclined column, steel inclined bracing and ring rod of the outer cylinder of the Guangzhou Tower and the relative deformation problem of the inner and outer cylinder under load and temperature, and reasonably release the internal force of the main beam of the floor connected to the outer cylinder, which not only ensures the unique and beautiful appearance of the Guangzhou Tower, but also ensures the overall safety and use performance of the Guangzhou Tower structure, which can be used as a reference for similar projects.
4. Construction technology innovation
The main tower structure of Guangzhou Tower is composed of oval concrete core tube and large diameter steel pipe oblique steel structure outer frame tube, the shape has the characteristics of twist, deviation, hollowing, etc., elegant and beautiful, but the structure construction is difficult, the construction accuracy requirements are high, for high quality, safety and efficiency to complete the construction goals, with the project as the carrier for technical research, breakthrough in a large number of technical problems, a large number of innovative technological achievements.
4.1 Large tower crane hanging technology
The steel structure column and other components of the Outer Frame Cylinder of Guangzhou Tower have a single-piece lifting weight of about 20~40t; the core barrel is a narrow elliptical section of 17m long shaft and 14m short shaft, and the interior is a dense elevator shaft; in order to meet the installation of a total of 50,000t steel structure, at least two large tower cranes can be arranged to meet the needs of the project.
According to the characteristics of the structure and the actual situation of the project, the M900D external climbing tower crane is used for the first time in China as shown in Figure 3, which realizes the breakthrough of "zero" of the heavy tower crane external hanging operation, effectively improves the construction efficiency and shortens the construction period.
Figure 3 External climbing tower crane
4.2 Antenna mast overall lifting technology
The 150m high antenna mast of The Canton Tower weighs about 1300t, and is divided into a lattice section and a solid abdominal section, which is set at a height of 454 to 600m, and the construction difficulty is high. This project has formulated a computer-controlled, hydraulic overall lifting process to complete the installation of the ultra-high mast in place of the technical scheme, that is, the length of 90m, weight 630t of the upper mast is first assembled in the abdomen of the lower lattice section, and then the use of computer multi-parameter automatic control hydraulic lifting equipment (4 groups of 20 through-center hydraulic jacks) set at the top of the lattice section (+529m) to achieve the ultra-high altitude continuous lifting of the antenna mast of the lifting section, rapid installation in place, effectively shorten the construction period, saving a lot of manpower and material resources.
4.3 Special-shaped overall lifting steel platform technology
According to the characteristics of ultra-high, elliptical and narrow core barrel, the customized overall lifting steel platform template body is designed, and the lifting system, platform system, template system, foot-hanging system, etc. in the constituent system are optimized and improved, reflecting the characteristics of high efficiency and energy saving:
(1) Make full use of the dynamic column in the core barrel as a bearing system, which has better economy.
(2) Realize the synchronous construction of horizontal and vertical structures in the core tube, greatly improve the stiffness of the core tube during the construction process, and ensure the safety of the core tube structure during the construction process.
(3) The overall lifting steel platform has a closed operating environment, which avoids the danger of falling from a high altitude and ensures the safety of construction.
(4) The steel mold system has good integrity and stiffness, which ensures the quality of concrete construction.
(5) The steel platform system can be lifted with load, which improves the efficiency of construction. In addition, the construction of this project also adopts three-dimensional space measurement technology, welding deformation control technology, comprehensive safety protection isolation technology, inclined steel pipe concrete structure construction and detection technology, special-shaped steel structure pre-deformation technology, temperature field monitoring and control technology and other innovative construction technology, the structure adopts Q415NH weathering steel, C80 high-performance concrete and other new materials, the comprehensive application of ten new technologies of the Ministry of Construction has reached the national leader, nearly 20 invention patents and utility model authorization, Through the above-mentioned scientific and technological innovation, the construction of The Canton Tower has been completed safely and smoothly and with high quality, and the scientific and technological achievements have been successfully applied to the construction of major projects such as Shanghai Center and Guangzhou West Tower.
5. Socio-economic benefits
5.1 Green building and energy saving benefits
Through the application and implementation of green building technology, the Guangzhou Tower project has achieved good results in terms of energy saving, land saving, material saving, water saving and indoor and outdoor environment improvement.
(1) Rational use of underground space, the ratio of the construction area of underground space to the building area is 69%, which effectively saves land resources.
(2) The annual power generation capacity of wind turbines is about 1000 degrees. BIPV photovoltaic curtain wall generates about 4900 kWh of electricity per year. Night lighting can save 2 million kWh of electricity per year. Heat pumps save 600,000 kWh of electricity per year to achieve energy-saving operation.
(3) Make full use of recyclable materials and save 1400 tons of steel through structural optimization, and the weight of recyclable materials accounts for 46.6% of the total weight of building materials used.
(4) The vibration control system and the fire water tank compatible design form, saving 1200 tons of steel, saving 2500 square meters of construction area, saving 50 million yuan of construction cost, but also saving the corresponding building material resources.
(5) The use of high-speed double car elevator, saving the construction area of the shaft 3168 square meters, saving the construction cost of 63 million yuan, but also saving the corresponding building material resources.
5.2 Social benefits
Since its opening, Canton Tower has received more than 5 million Chinese and foreign tourists and shined at the 16th Asian Games. It has applied a number of innovative technologies, displayed green building design concepts and technologies, publicized green building knowledge, attracted about 500,000 primary and secondary school students to visit and study, and carried out science education in green, low-carbon, environmental protection and other aspects, and achieved good social benefits. As the first tower building in China to reach 600m, Guangzhou Tower has set up ultra-high altitude meteorological and environmental monitoring stations (PM2.5), lightning warning, traffic monitoring, civil air defense, public security fire command and other public service facilities, providing a comprehensive and efficient platform for urban management in Guangzhou.
The Guangzhou Tower project has formed a large number of research results, has obtained 17 authorized patents, 1 software copyright, provided 5 standards, 1 work, 2 municipal construction methods as an important reference basis, and played a positive role in the promotion and application of research results. It has won more than 20 international, national, provincial and municipal awards such as the National Excellent Engineering Survey and Design Industry Award, the Sixth Architectural Society of China Architectural Society Architectural Creation Excellence Award, the China Construction Engineering Luban Award, the China Civil Engineering Zhan Tianyou Award, etc., forming a systematic independent intellectual property rights, providing advanced complete sets of technology for the construction of complex super high-rise structures, and the technical achievements have convenient portability and significant economic and social benefits.
6. Conclusion
(1) The use of high-performance glass curtain wall, natural lighting, efficient air conditioning and refrigeration system, frequency conversion water pump, heat recovery, new air utilization in the transition season, intelligent lighting and LED night lighting system, building intelligent control and sub-metering and a series of energy-saving measures, can effectively reduce the energy consumption of building operation.
(2) In all stages of construction, the rate of return on commercial value and the use and maintenance of later periods should be regarded as important indicators to guide the advancement of the project, so as to achieve "seamless integration" between construction and operation management, which is conducive to the implementation of the concept of green building.
(3) In view of the complex characteristics of the engineering structure system, the innovative design technology applied in this project provides a green building demonstration role for similar buildings.
First, the vibration control system and the compatible design form of the fire water tank are adopted, which provides a demonstration case for the design of super high-rise buildings at home and abroad to prevent wind, fire and earthquake disasters;
The second is the use of structural health monitoring system, which provides a demonstration case for how to use more economical, scientific and effective means to monitor the structural safety of super high-rise buildings;
The third is the use of high-speed double car elevators, which provides a demonstration case for how super high-rise buildings can make full use of limited elevator shaft resources, enhance transportation capacity, and reduce the number and energy consumption of elevator drive equipment.
(4) This project involves the complex system of structural characteristics of the super high-rise construction and construction of the construction of the required construction control technology, steel structure hoisting technology, antenna mast lifting technology, civil structure construction and other key technologies, because the system integrates control technology, information technology, Internet of Things technology, mechanical technology in one, so that in the development of key equipment and facilities, to ensure that the super high-rise construction is safe and reliable, good economy.
Through the successful demonstration of Canton Tower, it can provide reference and reference for other similar buildings, and can be promoted to the construction of other complex super high-rise structures and large-scale steel structure projects in the construction of green buildings.
(5) The application of green energy-saving technologies such as wind power generation, photovoltaic curtain wall, rainwater recycling and the promotion of experience achievements enable people to recognize the concept of green buildings saving energy, saving resources and returning to nature, guide the development of building design in a benign, environmentally friendly and sustainable direction, promote the development of green buildings, drive the development of building materials, high-performance equipment and other related industries, and improve the green environmental protection benefits of tower buildings and improve the public's awareness of environmental protection. Therefore, this project has significant social, environmental and economic benefits, and has important promotion value.