Shake‐table test performance of an inertial force‐limiting floor anchorage system

Abstract

Summary A new floor connecting system developed for low‐damage seismic‐resistant building structures is described herein. The system, termed Inertial Force‐Limiting Floor Anchorage System (IFAS), is intended to limit the lateral forces in buildings during an earthquake. This objective is accomplished by providing limited‐strength deformable connections between the floor system and the primary elements of the lateral force‐resisting system. The connections transform the seismic demands from inertial forces into relative displacements between the floors and lateral force‐resisting system. This paper presents the IFAS performance in a shake‐table testing program that provides a direct comparison with an equivalent conventional rigidly anchored‐floor structure. The test structure is a half‐scale, 4‐story reinforced concrete flat‐plate shear wall structure. Precast hybrid rocking walls and special precast columns were used for test repeatability in a 22‐input strong ground‐motion sequence. The structure was purposely designed with an eccentric wall layout to examine the performance of the system in coupled translational‐torsional response. The test results indicated a seismic demand reduction in the lateral force‐resisting system of the IFAS structure relative to the conventional structure, including reduced shear wall base rotation, shear wall and column inter‐story drift, and, in some cases, floor accelerations. These results indicate the potential for the IFAS to minimize damage to the primary structural and non‐structural components during earthquakes.

Seismic design and performance of steel concentrically braced frame buildings with dissipative floor connectors

“…[53][54][55] Recently, experiments including shake table testing have been conducted on reinforced concrete shear wall structures equipped with dissipative floor connectors. [56][57][58][59] Such connectors consist of either friction dampers or buckling restrained braces coupled with rubber bearings (RBs). These tests along with recent work by Tsampras and Sause [60] highlighted that dissipative floor connectors are effective in reducing earthquakeinduced acceleration demands, mitigating higher mode effects and minimizing structural damage during a seismic event.…”

Low‐damage steel structures for enhanced life‐cycle seismic performance

“…2a illustrates the plan view of a steel building which is designed with steel moment-resisting frames and steel CBFs in the east-west and north-south loading directions, respectively. The overall concept builds on prior related work on reinforced concrete shear wall structures [23,24]. Unlike conventional construction, the steel CBFs are connected horizontally to the gravity framing system with friction dampers, as shown in the same figure.…”

“…Alternative concepts for controlling earthquake damage in framed structures involve the use of dissipative floor connectors between the primary lateral load resisting system and the gravity framing system of a building [22–26]. These connectors allow for relative movement between the two systems, thereby controlling the amplitude of inertial forces passing through the floor diaphragms from one system to the other.…”

“…Allinall, the alternative building configuration has high potential to minimize earth quakeinduced repairs over a building's service life. tem and the gravity framing system of a building [22][23][24][25][26]. These connectors allow for relative movement between the two systems, thereby controlling the amplitude of inertial forces passing through the floor diaphragms from one system to the other.…”

Enhancing the Seismic Performance of Precast RC Frames with Cladding Panels through Setting U-Shaped Dampers and Rocking Walls

“…Twigdenand and Henry [22] experimentally investigated a posttensioned rocking wall with energy-dissipating O-connectors attached along the vertical. Zhang et al [23] combined precast rocking walls and friction dampers or buckling-restrained braces to form an inertial force-limiting floor anchorage system that is a low-damage seismic-resistant system. Feng et al [24] used rocking walls to mitigate the drift concentration issue of buckling-restrained braced frames.…”