SEISMIC BEHAVIOUR OF A SCALED 7-STORY BUILDING MODEL WITH LOW-DUCTILITY REINFORCED CONCRETE WALLS

Zavala C.; Diaz M.; Reyna R.; Cueva J.; Otero D.; Lopez L.; Isuhuaylas S.; Noa R. · World Conference on Earthquake Engineering proceedings (2024)

Resumen

Between 1997 and 2013, buildings with low-ductility walls using wire mesh as reinforcement without confinement at their edge were massively constructed in urban areas of Lima city. Real estate companies use this type of structure because of its lower price compared with conventional reinforced concrete or confined masonry walls. However, when walls started to grow in height, flexural and shear deformations occurred. These thin walls suffered high stress, producing cracks in the basement or cracks in the location where the mesh from the lower story ended. This behaviour is investigated in a 1/10 scaled model, reproducing the record of the October 3, 1974, Lima earthquake as an input-scaled signal. The model was scaled using the appropriate scale in material, geometry, and time signal. The model was set on a shaking table in the structural laboratory of CISMID and input signal was increased to produce the hysteresis on the specimen. The first test measured the dynamic properties of the specimen by free vibration to evaluate the damping ratio and the initial period on the structure. Then, earthquake records were applied to the model, scaling to moderate, severe, rare seismic levels. The response was measured using laser sensors, objectives & video camera algorithm and accelerometers on each floor and over the table. The behaviour of the specimen showed flexural and shear combination damage of the model in the lower part, cutting the reinforcement and the concrete. In this paper also, numerical simulations with FEM analysis were performed to reproduce the experimental results with confidence.

Instituciones: Universidad Nacional de Ingeniería