Seismic Performance and Evaluation of Controlled Spine Frames Applied in High-rise Buildings

Abstract

A controlled spine frame system consists of moment frames and spine frames with concentrated energy-dissipating members. This system guarantees the continuous usability of buildings against Japanese Level-2 earthquake events (similar to DBE events in California), and the authors have confirmed its excellent performance in preventing damage concentration in low-rise buildings. This study further investigates the effect of diverse structural properties on the seismic performance of controlled spine frames applied in high-rise buildings. The effect of building height, yield drift of dampers, spine-to-moment frame stiffness ratio, and damper-to-moment frame stiffness ratio are illustrated in detail, and optimal values are discussed. Also, a segmented spine frame system is proposed for high-rise buildings. The simple evaluation procedure proposed by the authors for low-rise buildings, based on equivalent linearization techniques and response spectrum analyses, was modified to include higher-mode effects for high-rise buildings based on modal analysis. The modified evaluation method was verified by modal pushover and time-history analyses.

Seismic performance of rocking‐delayed spine frame system with base initial gaps

“…in s w 0 (11) Equation ( 9) can be split into Equations (12) and (13). Equation (12) represents the forces from the dampers and vertical load F w and Equation (13) the forces from the strands as expressed below:…”

Higher‐mode force response in multi‐story strongback‐braced frames

“…Like shear walls and rocking-braced frames, higher modes have been identified as the cause of near-elastic force demands in pivoting strongback-braced frames (SBFs) that employ an elastic truss, or strongback. [15][16][17][18][19][20] SBFs are composed of an elastic and nonlinear truss; see Figure 2B. The strongback-comprised of the elastic truss including the elastic braces, tie, and column shaded in gray in Figure 2B-is proportioned to remain essentially elastic, resulting in a relatively stiff and strong vertical backbone that engages every story in a pivoting displaced shape.…”

Super elastic system using parallel spine frames with steel braces

“…Effective and economical structural systems that mitigate damage concentration and residual deformation after major earthquakes are essential for enhancing the resilience of building structures toward earthquakes. Earlier studies 1–10 have verified the efficacy of pin‐supported high stiffness steel braced frames or reinforced concrete (RC) walls, i.e., structural spines, to improve structural integrity and avoid deformation or damage concentration for various structural systems, such as reinforced concrete buildings, 1,2 deficient concentrically braced frames, 3 buildings with various heights, 4 ‐ 6 strongback system for steel‐braced frames, 7 and several other configurations 8–10 …”

“…Energy dissipating members (a) Previous system [4][5][6] (b) Proposed system F I G U R E 2 Self-centering mechanism of structural systems adopting spine frames the self-weight combined with posttensioned members are typically used to generate self-centering lateral force. Various configurations have been proposed.…”

“…Atasever et al 31 conducted extensive numerical analyses and found that when postyield stiffness ratio is larger than 0.1, the residualto-peak drift ratio is generally less than 10% for level-2 earthquake intensity in Japanese building design code. In previous studies on controlled spine frame systems, [4][5][6] envelope moment-resisting frames have been designed to remain fundamentally elastic and consequently provide self-centering force during major earthquakes (Figure 2a). This approach by increasing the postyield stiffness is usually more economical than creating a flag-shaped hysteresis property.…”