CIVIL ENGINEERING 365 ALL ABOUT CIVIL ENGINEERING



AbstractA novel bolt-connected precast concrete wall panel structural system has recently been proposed for low-rise buildings in rural areas. The system features replaceable distributed bolt-connections adjoining walls, floors, and connecting columns fixed in base, enabling the whole system to be demountable and remountable. Previous quasi-static cyclic push-over test results showed an unfavorable punching shear failure of bolted joints without fully mobilizing the strength of the wall panels. Therefore, the connections were strengthened by using high-strength bolts and adjusting the positions of bolts. In order to evaluate the seismic performance of the precast system with the improved connections, incremental dynamic shake table tests were performed on a full-scale two-story building. Seismic demands and capacities of the precast building with connecting columns fixed in base (Model I) and without fixed-base constraints (Model II) were compared. The experimental results highlighted the high capacity of the improved precast system against beyond design-basis earthquakes with a peak ground acceleration of up to 0.8 g. Only slight to moderate damage was observed in terms of cracks at the edges of the door/window openings, similar to those on a cast-in-place structure, followed by cracks on concrete at connections. Although Model I showed higher lateral stiffness and lower seismic fragility, seismic energy was dissipated more evenly throughout the whole structure of Model II, which was proven well suited for low-rise buildings. Insight was given to explain the improvements on the bolt connections and the reinforcing effects of the connecting columns to provide references for the potential application of the proposed precast system.



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