Study on the Effect of Extra Pole Support on Seismic Resistance for Low‐Rise RC Structures

Abstract

There is a common way to enhance the collapse safety of residential houses using extra tilted poles supporting poor structures from the outside before and/or after earthquakes in seismic regions, especially in rural areas. But, almost all of these supporting measures are still weak and lack of scientific design and evaluation. This study takes a poorly designed two‐bay and three‐story RC frame building as an object to explore the effect of this kind of support measures on structural seismic resistance by comparing with a standard‐designed RC frame structure model as a contrastive case. The results obtained by performance‐based methods indicate that extra poles can improve the seismic collapse safety and reduce structural seismic damage of the poorly designed structure (PDS) effectively. The median collapse capacity parameter θ increases from 1.31 g to the range of 1.92∼2.39 g, and Sa(T1; 10%) (spectral acceleration at the first‐mode period which causes 10% probability of structural collapse) also increases from 0.57 g to the range of 0.75∼1.08 g. Study of dynamic structural damage shows a great damage reduction of PDS under seismic loads, especially Sa(T1) = 0.2 g. This study proves that this simple measure can improve the seismic resistance of PDS into an acceptable level by taking our suggested practical and efficient supporting schemes.