TO STUDY THE EFFECT OF SOFT STOREY TO LATERAL STIFFNESS OF REINFORCED CONCRETE STRUCTURES UNDER SEISMIC EXCITATION

Abstract

Reinforced Concrete was discovered by Joseph Monier. Due to its speed of construction, flexibility, sustainability and easiness to cast, it became the first choice of civil engineers of 19th century. Many RC structures have been constructed and many others are still in progress. Similarly, in other countries, our country Pakistan has many ancient RC structures. RC structures are subjected to lateral loads due to earthquake and wind. Especially northern areas in Pakistan are subjected to more earthquakes. The structures should be able to resist these lateral loads and suffer least damage during earthquake. As in the high-rise buildings parking is usually provided at the ground floor. Due to more open space requirement for parking purpose the stiffness of the ground floor is comparatively less as compared to upper stories. So this bottom storey behaves as a soft storey. In order to improve the stiffness of this soft storey for better seismic response various techniques are used like shear walls and CFRPs etc. But a more economical of all these options is Galvanized steel welded wire mesh which is usually wrapped around the reinforcement of beam-column joint region. So, in this way it provides better confinement and hence better seismic performance of RC structures by increasing their ductility.