Office building in Beijing (China World Trade Centre Phase 3)

Office building in Beijing (China World Trade Centre Phase 3)

Building use

Office building

Country/Region

All Regions

Overview

Various structural types, utilising different materials, have been explored until the final design was accomplished, which comprises a composite braced frame core and a composite perimeter frame, linked by two outrigger systems at relevant E&M floors.

Basic information (construction date, number of stories, gross floor area, adopted design code, engineer(s), Contractor(s), etc.)

Construction date: 2007
Number of stories: 74
Gross floor area: 190,000m2
Adopted design code: GB50068-2001; GB/T50083-97; GBJ132-90; GB50009-2001; GB50011-2001; GB50010-2002; GB50017-2003; JGJ99-98; JGJ6-99 for Tall Buildings; JGJ94-94; DBJ01-501-92; JGJ3-2002; JGJ138-2001; BS8110; BS5950; BS5400; IBC-2000; FEMA356 of Building; ATC40; AS/NZS1170.2:2002
Engineer(s): Arup
Contractor(s): China State Construction Engineering Corporation First Bureau Development Co. Ltd.

Issue and/or innovation

The Mega Tower, China World Trade Centre Phase 3, Beijing China is 330m high and composed of a five-star hotel, grade-A office levels and multi-purpose spaces. The height of the building and the high seismic design intensity in Beijing poses a great challenge to the structural engineers, especially considering various stringent requirements by Chinese codes. Various structural types, utilising different materials, have been explored until the final design was accomplished, which comprises a composite braced frame core and a composite perimeter frame, linked by two outrigger systems at relevant E&M floors. The tapered elevation of the tower building necessitates three transfer belt trusses that allow the reduction in number of perimeter columns in middle and high zone of the tower. The use of 8 storeys high V-shaped columns with transfer belt truss admit of the grand entrances with wide spacing of columns at ground floor for the five-star hotel and grade-A office, and meanwhile provide a smooth structural transition to the perimeter moment frame above. Composite elements of various types are extensively used and positioned carefully to satisfy the combined requirements for stiffness, ductility, redundancy, and cost-effectiveness. The composite steel plate wall (C-SPW) is implemented in the structure, possibly the first time in China, to increase the shear capacity and stiffness and improve the ductile behaviour at specific zone. Accurate finite-element analysis and advanced non-linear elasto-plastic time history analysis have been carried out to evaluate the structural behaviour and ensure the building safety under different seismic levels.

Specific solution/technical details

“A variety of steel concrete composite components are strategically widely used to achieve cost effectiveness in earthquake resistance and increase the available floor area. The use of steel plates embedded in the bottom concrete core wall improves the ductility of traditional concrete walls, significantly improving seismic performance. Unlike the regular rectangular shape of the composite columns in perimeter frame, the composite columns in the core are of L shape or rectangle with multiple (no’s 2 to 7) steel stanchions cast in. Steel beams and braces are connected to these steel sections directly. The design complexity of such columns has been fully envisaged and verified with both international codes and finite element analysis.

Impact or effectiveness

The composite structural system achieves the best cost-effectiveness in terms of structural safety in high seismic zone, cost and construction speed. To compare with the final scheme, a pure steel scheme is much more expensive which also requires a damper to satisfy the people comfort under wind. The concrete scheme is difficult in that concrete core wall cannot satisfy the strength capacity and ductility requirement in severe earthquake. The cost is 23% lower than a pure steel scheme. The construction from B4 level to top-out (totally 78 stories)only took 15 months, which is much faster than a concrete scheme.

References / Technical Papers Content

GIBBONS, C., HO, G., WANG, Y., LIU, P., KWOK, M., TSUI, J. 2005. “THE STRUCTURAL DESIGN OF THE MEGA TOWER, CHINA WORLD TRADE CENTRE PHASE 3, BEIJING CHINA.” J.Tall Buildings: From Engineering to Sustainability. 396-402.