Investigation of soft story irregularity in reinforced concrete buildings with hollow block slab

Hollow block slab is commonly used because of its construction and architectural advantages. Contrary to its advantages, this slab type has some disadvantages that have negative effects on building performance. Specially, shallow beams that has widely used in hollow block slab type cause low lateral stiffness in reinforced concrete buildings. Low lateral stiffness increases interstory drift ratios and earthquake damages. In case of using of hollow block slab in building with soft story risk, lateral stiffness of building is additionally decreased and interstory drift ratios of building are increased. Soft story is a irregularity that arises from low lateral stiffness and causes heavy building damages in earthquake. This irregularity is seen specially ground floors due to commercial reasons. For increasing commercial efficiency, increasing of ground story height decrease lateral stiffness and increase interstory drift ratios of ground story. In this study, reinforced concrete buildings with hollow block slab that have soft story irregularity risk were investigated. For this purpose, reinforced concrete buildings with hollow block slab were designed with different ground story height. These buildings were analyzed numerically. In this study, reinforced concrete buildings with slab-and-beam floor were designed and were compared with reinforced concrete buildings with hollow block slab. Reinforced concrete buildings were firstly analyzed with Response Spectrum Analysis Method taking into linear behavior of building. Because of excessive interstory drift ratios of buildings with hollow block slab, buildings with hollow block slab were investigated taking into nonlinear behavior and these buildings were analyzed with pushover analysis. According to analysis result, effect of increasing ground story height on building with hollow block slab was investigated. According to analysis result, increasing of ground story height of reinforced concrete buildings with hollow block slab have negative effect on building performance. Also it was seen that reinforced concrete buildings with hollow block slab have more interstory drift ratios than reinforced concrete buildings with slab-and-beam floor.