A comparative case study on seismic design of tall RC frame-core-tube structures in China and USA

Abstract

To evaluate the major differences between the Chinese and the United States (US) seismic design codes from a structural system viewpoint, a comparative case study is conducted on a tall frame-core tube building, a typical type of reinforced concrete (RC) system widely constructed in both countries. The building, originally designed using the US seismic design code, is firstly redesigned according to the Chinese seismic design code based on the information provided by the Pacific Earthquake Engineering Research Center (PEER). Secondly, the member dimensions, the dynamic characteristics, the seismic design forces and the material consumptions of the two designs are compared in some detail. Subsequently, nonlinear finite element models of both designs are established to evaluate their seismic performances under different earthquake intensities. Results indicate that the seismic design forces determined by the Chinese response spectrum are larger than those determined by the US spectrum at the same seismic hazard level. In addition, the upper-bound restriction for the inter-story drift ratio is more rigorously specified by the Chinese code. These two aspects have led to a higher level of material consumption for a structure designed by the Chinese code. Despite of the above, the two designs yield roughly similar structural performances under earthquakes.

Seismic loss assessment of typical RC frame-core tube tall buildings in China and US using the FEMA P-58 procedure

“…All design details of Building 2N, including the structural configuration and dimensions, the vertical design loads, the site conditions and the seismic hazard level, are identical to those for Building 2A. A detailed comparison of the two designs can be found in Lu et al (2015). Lu et al (2015) indicates that Building 2N has larger columns and more internal walls in the core tube.…”

“…In addition, the maximum acceleration response occurs at the top floor in both buildings. Figure 2(c) shows that the coupling beam rotations are obvious greater for Building 2N, as the coupling beams in Building 2N have larger span-depth ratio than those in Building 2A (Lu et al, 2015).…”

“…A detailed comparison of the two designs can be found in Lu et al (2015). Lu et al (2015) indicates that Building 2N has larger columns and more internal walls in the core tube. The seismic design forces determined by the Chinese response spectrum are larger than the US counterparts at the same seismic hazard level.…”

“…Modeling details can be found in Lu et al (2015). The nonlinear THA is intended to assess and compare the performances of Buildings 2A and 2N for different earthquake intensities.…”

“…The prototype building is originally designed using the US seismic design codes, provided by the TBI Project (Moehle et al, 2011). Then the prototype building is redesigned according to the Chinese seismic design codes with the same design conditions and seismic hazard level (Lu et al, 2015). Detailed nonlinear FE models are established for both designs.…”