In high-rise diagonal grid structures, the Y-shaped connections play a key role in transferring the diagonal members of upper stories to the lower columns. Four reinforced concrete Y-shaped specimens were designed based on two factors: the volumetric ratio of stirrups in the joint zone and the material strength of the inclined members. They were then tested from loading to failure. The reduction coefficient of stirrups was defined and determined, leading to proposed design recommendations and expressions for determining the load-bearing capacity of reinforced concrete Y-shaped connections.

In order to study the seismic behaviors of fabricated steel frames with bolted beam-height adjustable steel beam-to-column connections (BHA connections), a six-story steel frame was designed to run pseudo-dynamic experiments. Experiments were first carried out with the steel frames with and without buckling-restrained braces (BRBs) under three different types of seismic records under 35 gal and 70 gal. Then the seismic records of EL_CENTRO amplified from 220 gal to 1,600 gal were loaded on the braced frame. Results showed that there was no detachment, sliding, or yielding detected in BHA connections. After BRBs were installed, the story drift and the top-story maximum displacement could easily meet the codes, and the structure was still working in the elastic stage under 620 gal. It could therefore be concluded that BHA connections have excellent seismic performance and they are suitable for application in fabricated steel frames. The braced frame using BHA connections has good lateral stiffness and energy dissipation capacity.