The Japanese COCOON project is a box-shaped, unit-shaped glass curtain wall. The architectural shape resembles that of a white silk ribbon. The building is named COCOON. The idea is that clothing is made from silk and students will break out like silkworms after they learn.
The COCOON building not only has the appearance of a cocoon, but also has a framework structure that absorbs many advantages of the cocoon. In general, buildings with strong earthquake-resistance capacity will appear bulky and rigid, because most of the modern reinforced concrete buildings are hard-stiffened against earthquakes. The safety of the buildings is ensured by deepening the foundation, strengthening the solidity of the materials, and strengthening the structure. The silkworm cocoon building has shown an alternative way of thinking - with Rocco just to attract and resolve external impact with a unique shape structure, thus ensuring its own stability.
The building is divided into two parts, consisting of a 50-storey tower and a 6-story circular commercial exhibition hall. The tower is surrounded by a three-sided steel frame structure in the central position of the "core", the main frame is a steel grid structure, and its surface layer and a layer of steel and external structure of the main body of the protection net. When an external force acts on such an oblique grid structure, the building is shaken. At this time, the impact force received from a fulcrum is dispersed in each fulcrum of the upper, lower, left, and right, and the external force received by the whole building is dispersed, and the shaking is also followed. Be attracted. This structure can not only increase the strength of earthquake resistance, but also effectively absorb the shaking caused by the wind.
The foundation structure of the building is very strong, and 36 steel piles with a diameter of 2.5 meters and a length of 16 meters were first driven into the deep underground, and then a 1 meter thick foundation cushion was laid on top of it. The concrete below the building is 3.8 meters thick.
The tower is more than 200 meters high. For those at the top of the building, it is not easy to escape in the event of an accident. For this purpose, an open and closed emergency rescue platform was specially designed on the top of the building for helicopter rescue operations. This platform is usually closed, and it only takes 7 minutes to open it if needed. However, the platform can not afford much weight. Helicopters cannot land on this platform and can only perform vacant rescue.
The more than 200 meters of the tower is surrounded by oblique lattices of the main steel frame from three directions. The three main steel frames are only integrated in the upper part of the building, while in the lower part they are separate and the three feet are above the foundation. This uniquely designed enclosure gives the building a high level of structural strength. The middle part of the “core” structure surrounded by the enclosure is connected to a shock absorber device that can attract lateral shaking. About 30% of the shaking caused by external forces can be attracted by this device, and the other 70% will be absorbed by other building components including the base.
Through rigorous performance testing; design performance:
1, wind pressure performance: use life is considered in 100 years, the maximum wind pressure (extracted wind tunnel results), the top +3000,-6220 N/m2 (+306,-635 kgf/m2);
2. Inter-layer displacement follow-up: 1/1000 or less;
3. Seismic performance: Small earthquakes can be used without repairing basically. Medium-sized earthquakes can be used only with glue. Large earthquakes require that the parts of the curtain wall do not fall off.
4. Water-tight performance: no water leakage occurs under the conditions of fluctuating average of 1920 N/m2 (196kg/m2) and pulsation upper limit of 2670 N/m2 (196kg/m2);
5, airtight performance: pressure difference 10Pa leakage volume is below 0.01m3/h.m2, pressure difference 100Pa leakage volume below 0.1m3/h.m2.