- Metro Complex -
Shanghai ZF Architectural Design Co., Ltd. has made in-depth researches and active explorations on various technologies of buildings near the Subway Station. In recent years, the company has participated in a number of projects with favorable access to the subway, undertaken construction & design of Jing’ an Phoenix Garden, Hongkong New World, CIFI Century Square, SML Commercial Center and other projects with favorable access to the subway, and accumulated rich experience. Moreover, the company has organized its professional and technical team to finish compilation of “Summary of Building Complexes over the Subway”. Currently, the completed SML Commercial Center in Luwan district is the first domestic oversize urban complex with favorable access to the subway. During design of this project, ZF undertakes all architectural design work, structural design of part of the subway and cooperation in other specialties. This project becomes the most influential landmark building with favorable access to the subway in the center of the city, and the company has obtained the core competitiveness in the buildings with favorable access to the subway in Shanghai and even the whole country.
Project Case: SML Central Square
It is the first domestic oversize complex with favorable access to the subway, which is located at the confluence of Xujiahui Road and Ruijin No.2 Rd. The metro line 9 is aslant the base and the station hall at Dapu Road. The platform is located in this property. The project includes one mega-high-rise office building with an area of 45,965m2, two high-rise apartment office buildings with the area of 19,560m2 and 19,154m2 respectively, commercial podium 95,739m2, and underground building 126,601m2; the total height is 145m, the office building is 99.5m high, the podium is 24m high, and the depth is 26.27m below the ground.
Project Difficulties:
Passenger flow organizing
As an oversize urban complex integrated with the subway, its passenger flow organizing is a difficulty. As for the commercial passenger flow, this project has exit & entrance and underground walkway for the subway at the second floor underground. They are connected to the surrounding plots (such as the Golden Magnolia Plaza, Hisense Plaza, etc.), and an underground road network is formed; meanwhile, a pedestrian overpass is reserved at the third floor underground, and it also will be connected to the surrounding property later forming an overhead gallery, which will link the commercial activities in the whole region. As for the office passenger flow, this project has special hall along Xujiahui Road and Ruijin No.2 Rd respectively. The office workers can take the direct elevator to the roof garden at the sixth floor and enter the office hall, so there is no interference between the office and commercial passenger flow. As for the traffic passenger flow (mainly subway passenger flow), this project has 4 separate exits & entrances in total, through which, people can go up to the ground level, or enter the shopping mall through the sunken square at the second floor underground.
Vehicle flow organizing
In order to maximize the commercial value of this project, no parking area and waiting area will be arranged on the ground. All the taxis will park in the special area at the first floor underground, and the passengers can enter the shopping mall directly after getting off the taxi; public vehicles will park at the third floor underground, and the people can directly reach the shopping mall or office building via the elevator; in addition, considering the traffic situation in the center of the city, special unloading area is arranged at the first floor underground for temporary parking of the trucks.
Fire control safety
The underground buildings of this project cover an area of 135,000m2. For this underground commercial building with such a huge volume, fire control safety is really a difficult issue. The specification requires that strict fire control areas should be arranged for the underground commercial building covering an area of more than 20,000m2. Therefore, this project achieves separation of fire control by adopting the design of underground commercial street without a trace; in addition, considering particularity and fire control safety of the subway, the arrangements should be relatively independent. However, increase of the underground commercial value and other factors also should be taken into consideration; this project effectively solves such difficult issue through design of the sunken square.
Uneven settlement
Considering that this project is the first high-rise buildings and the complex with overall seamless connection to the subway in Shanghai and even the soft soil area, the uneven settlement on the superstructure with a large volume will greatly affect safe operation of the subway line. Therefore, regarding treatment of the pile foundation, this project adopts the pile-end bearing stratum with less settlement, and adopts the post casting technique in bored concrete pile, so that the quality of pile body is improved, and the absolute settlement of pile foundation of mega-high-rise building is put under effective control.
Noise and vibration
Similarly, due to the seamless design between this project and the subway station, the noise and vibration caused during operation of the subway to the superstructures will directly affect the commercial value of this project, and also will bring impacts to the human body. Therefore, we firstly apply the principle of mechanics and adjust the mass ratio of the subway station, so that the impacts of vibration and noise caused during operation of the subway on the superstructures are put under effective control; moreover, the rubber shock absorbing zones are arranged at both ends of the exits & entrances of the subway station, which further reduce transmission of the noise.
Leakage
This project has a large number of underground spaces. How to reduce the impact of leakage on the subway and commercial facilities effectively is indeed a difficult issue in our design for this project. Therefore, we consider not to arrange a permanent settlement joint between the subway station and property basement, so as to achieve the overall seamless connection between the subway and property basement, which effectively reduces the probability of water leakage and improve the anti-leakage performance by several times of the requirement of the specification; moreover, we adopt the technique of clay liner of rock wool plus expansive soil, and improve the design nodes of the clay liner, so as to solve the waterproof issue permanently.
Construction progress
This project has a large work quantity and tight development period, and involves a number of coordination departments. The period from design and completion is only 4 years. Therefore, some unconventional technical measures must be adopted. Upon coordination and communication with the building unit, this project adopts the one-time excavated deep foundation pit for construction, and arranges the late poured band and construction joint for sectional construction upon the structural divisions, so that the difficult technical issue of parallel design and construction of the subway and superstructure is solved successfully.
Economics
Economics of the project is not only the issue that the developer concerns, but also the core competitiveness of us (the design unit). In response to the mega-high-rise building C of this project, we use the steel tube frame column. Compared to the common concrete column, the steel tube column reduces the section size, increases the effective usable area of the building, and improves the space effect of the building; use new joints of profiled steel concrete beam and column in combination with reinforced steel concrete cast-in-place floor slab to ensure safety and economics effectively.