This research of a state-of-the-art structural system with aseismic columns and three-hinged dampers (THDs) in the first story (isolated story) has been accomplished.
At first, the configurations of the newly patented damping devices were introduced. Then, their mechanical properties of several different types of THDs were investigated through both mathematical simulation and experimentation in order to obtain the corresponding design parameters. Finally, parametric studies with different aspect ratios of THDs were fulfilled to clarify the relationship among the stain, strength, stiffness and ductility, which will be beneficial to the aseismic design of building structures.
To explain in detail the design procedure of the new aseismic structural system, a design example of 6-story building with one-story basement was demonstrated. During the structural analysis, the piers and spandrels of the building were modelled by using the frame members. In addition, the junctions between piers and spandrels were modelled by using the rigid member. After completing the structural modeling, the seismic lateral loadings were applied on the building according to the non-linear static pushover method to evaluate the performance-based design. Besides, the non-linear dynamic time-history analyses were carried out based on the same base-shear forces with the corresponding pushover cases.
Observed from the analytical results, building with aseismic columns and THDs in the ground story can survive more than the design maximum credible earthquakes. When the practical building subjected to severe vibration, the plastic rotations of the aseismic columns are within the life-safety performance and the relative displacements of the isolated story are also within the low-ductility range. Owing to the plasticity can happen on both the aseismic columns and THDs when the strong earthquake shakes the building, the seismic forces in the upper stories are approximately constant. So, the upper part of the well-designed structure can deform elastically without resulting in apparent concrete cracks.
KEYWORDS: base-isolation, damper, ANSYS, ETABS, SAP2000,
pushover analysis, time-history analysis, slab - wall structure.