UC San Diego

This thesis studies the seismic response of an eighteen-story core wall building with force-limiting connections and low-damage coupling beams. Force-limiting connections allow the movement of the gravity load resisting system (GLRS) relative to the seismic force-resisting system (SFRS) and control the seismic-induced horizontal forces transferred between the two systems. Past research developed force-limiting connections that consist of a friction device or a buckling-restrained brace along with low-damping rubber bearings for buildings with planar SFRS with flexural inelastic base mechanism or rocking base mechanism. This thesis considers a force-limiting connection modified to accommodate the three-dimensional kinematic requirements between the GLRS and the SFRS in a reinforced concrete core wall building. The discrete variable limiting force is a novel characteristic in the force-displacement response of the modified force-limiting connection. Low-damage coupling beams, which consist of steel coupling beams with rotational friction connection ends, provide controlled moments with nonlinear responses concentrated on the rotational friction connections. Three-dimensional earthquake numerical simulations of an eighteen-story core wall building with modified force-limiting connections and low-damage coupling beams are performed. The use of modified force-limiting connections reduces the magnitude and the variability of the seismic-induced shear force, torsional moment, and acceleration responses of the building compared to the conventional core wall building with monolithic connections between the GLRS and the SFRS of the building while maintaining a reasonable connection deformation. The use of low-damage coupling beams instead of reinforced coupling beams could potentially reduce the coupling beam damage to accelerate the post-earthquake functional recovery of the building.