Office building in Shenzhen

Building use

Office building

Country/Region

China

Overview

Steel and concrete composite outer frame columns were adopted to provide sufficient strength and stiffness, effectively bearing vertical and horizontal forces. The composite floor slabs and lower steel beams were also adopted to facilitate beam height control, save building floor height, and control building quality, reduce the impact of earthquake action, and improve building safety.

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

Construction date: 2017
Number of stories: 64
Gross floor area: 231,900m2
Adopted design code: GB 50223-2004; GB 50009-2001; GB 50011-2001; GB 50010-2002; JGJ 3-2002; GB 50017-2003; JGJ 138-2001; GB 50204-2002; GB 50205-2002; GB 50045-95 (2005 edition); JGJ 3-2002
Engineer(s): Beijing Architectural Design and Research Institute Co., Ltd
Contractor(s): China Railway Construction Engineering Group Co., Ltd

Issue and/or innovation

The use of steel and concrete composite components can provide greater structural efficiency, improve structural toughness, control cross-sectional dimensions, reduce structural weight, reduce seismic response, and fully leverage the performance of different materials. However, at present, the common composite columns include concrete-filled steel tubular columns and profiled steel concrete columns. The quality of concrete pouring inside concrete filled steel tubular columns is not guaranteed, and the drying shrinkage of internal concrete can easily lead to the degradation of component stiffness, affecting the bearing capacity and lateral stiffness. At the same time, the fire resistance of concrete filled steel tubular columns requires separate treatment, increasing costs and expanding the size of structural columns. The construction process of steel reinforced concrete columns is complex, and the contribution rate of steel is low. The composite steel tube concrete column material used in this project has a high utilization rate, is convenient to connect with the steel beam, does not require fire prevention treatment, and saves project cost.

Reason for composite solution

Composite columns have the advantages of both steel and concrete structures, with large vertical bearing capacity and overall stiffness, good plastic deformation capacity and ductility, and excellent seismic performance. Using steel and concrete composite outer frame columns can provide sufficient strength and stiffness, effectively bearing vertical and horizontal forces, with higher strength than steel columns, and smaller section than concrete columns, which is conducive to building layout. The use of high-strength steel materials and high-strength concrete (C60 or higher) will make the advantages of steel concrete composite cross-section columns more prominent. This is also conducive to the installation of steel structures, making better use of the high-strength performance of concrete. The use of composite floor slabs with thin and thick slabs and small loads saves materials on the one hand and reduces the load effect on the other. The composite floor slabs and lower steel beams form composite components through steel studs, and the upper floor slabs compress and the lower steel beams work together in tension. This can fully exert various material properties, facilitate beam height control, save building floor height, and control building quality, reduce the impact of earthquake action, and improve building safety.

Specific solution/technical details

1. The square steel tube is filled with concrete while being wrapped with concrete to form a square steel tube stiffened column. The concrete and steel structure bear the force together, improving the efficiency of the component, controlling the cross-sectional size, and preventing concrete compression, main tensile strength of the steel tube, and instability and fire protection of the square steel tube.
2. The profiled steel plate and concrete form a composite floor slab. During the construction phase, the profiled steel plate can be used as a template. During the use phase, the profiled steel plate participates in the stress, saving the reinforcement and formwork processes.
3. The steel beam is connected to the floor slab through studs to form a composite section, which is jointly stressed to improve structural efficiency.

Impact or effectiveness

1. Improved component efficiency and safety of building structures
2. Saving structural materials
3. Simplify the construction process and save construction procedures such as structural formwork
4. Convenient connection node construction, such as steel beams that can be directly connected to square steel pipes in columns, eliminating the need for embedded parts.
5. The project cost is saved, the consumption of concrete materials is saved, and the expenses for fire prevention treatment of structural columns are saved
6. It brings a better sense of use, controls the size of structural columns, expands the space of the exterior facade, reduces the beam height, and has higher headroom.

References / Technical Papers Content

Shu Weinong, Gao Jianmin, Song Ling, et al. 2009. “Design and Research on Super High Rise Structure of Block A in Lot T106-0028, Nanshan Central District, Shenzhen.” J. Building Structure. 039 (012): 127-131.