رفتار لرزه ای اتصالات پایه پیچ خورده بین دیوار بتن آرمه از جنس فولاد و میله SRC Seismic Behavior of Bolted Endplate Connection Between Steel Reinforced Concrete (SRC) Wall and SRC Beam for Use in High-Rise Buildings

1 Introduction As an efficient structural system to resist lateral forces, the reinforced concrete (RC) coupled shear wall has been widely used for substantial lateral load-carrying capacity, stiffness and energy dissipation capacity. For super high-rise buildings, however, RC walls may not be adequate at the bottom story, where the shear wall is subjected to high levels of axial load, flexural moment and shear during strong earthquake excitations. By introducing steel shapes, the axial load-carrying capacity and lateral force resisting mechanism of RC walls can be significantly improved without much increase in wall thickness, resulting in the so-called steel reinforced concrete (SRC) composite walls. The most fundamental type of SRC composite walls frequently used in super highrise buildings contains embedded H-shaped steel columns at the boundary elements. To achieve even better seismic performance, steel plate or diagonal braces can be added at web of wall between the H-shaped steel columns at boundary elements, as shown in Fig. 1. Previous research [1–4] has demonstrated that SRC composite shear walls can be designed to have excellent seismic performance in terms of load-carrying capacity, post-yield deformation and energy dissipation capacities. Similar trend can also be seen in the development of coupling beams in RC coupled shear walls. To improve the ductility and energy dissipation capacity under large shear deformation reversals, SRC composite coupling beams where steel plate is embedded in RC coupling beam has been proposed and studied by Lam et al. [5], Gong and Shahrooz [6, 7] and Nie [8]. Research results indicated that the key to the successful application of SRC beams is the selection of embedment length of steel plate into RC wall piers. With adequate embedment length and appropriate detailing, steel and concrete composite coupling beams can exhibit excellent seismic behavior in terms of post-yield deformation, ductility and energy dissipation. However, direct embedment connection details cannot be applied to join SRC beams and SRC wall piers due to the existence of embedded H-shaped steel column at boundary elements of wall piers. A conventional solution to this problem is to field weld the steel shapes of composite coupling beams to the flanges of embedded steel shapes at boundary elements of the composite wall piers. It is without doubt, however, that the field welding may cause difficulties in construction and quality control, resulting in the increase of overall construction cost. To achieve better constructability, it is necessary to develop an alternative type of connection for composite coupling beams and composite wall piers that is not only convenient for construction but also adequate to ensure the performance objectives of composite coupling beams.