Analysis of seismic pounding of moderate-height rc buildings with aligned slabs

Resumen

Collision between adjoining buildings is relevant, since the huge impact forces significantly modify the buildings dynamic behaviour. The separation required by the regulations avoids pounding; however, even in recent buildings, impact can occur due to not fulfilment of codes and seismicity underestimation. Given the importance of this issue, the main objective of this work is to provide efficient simulation tools and to study the relevance of seismic pounding into the most common situations. This work presents a summary of the theoretical developments, discusses the most common simulation software, provides an overview of the previous research, offers recommendations to researchers, and identifies research needs. A new formulation is introduced to estimate the Kelvin-Voigt model damping parameter; it is selected by releasing one of the assumptions of the previous formulations, i.e. considering the influence of the colliding building structures. A simplified parametric study oriented to investigate the performance of the proposed formulation is performed; as well, criteria for selecting their input parameters are provided. Numerical examples on pounding between two multi-storey multi-bay RC buildings are presented, and a shaking table pounding experiment is numerically simulated with the proposed formulation. This Thesis presents a parametrical study on seismic pounding between adjoining short-to-mid height RC framed buildings with aligned slabs. Such condition has been chosen for being highly widespread, mainly in developing countries; two 3 and 5-storey buildings are selected. The buildings are designed for high seismicity. The study consists of analysing the dynamic response of the colliding buildings to a number of representative strong seismic inputs. The inputs are selected based on the soil type and the existence of velocity pulses. Pounding is described by a Kelvin-Voigt linear model; its damping coefficient is derived after the estimated coefficient of restitution by following traditional and more advanced formulations. The behaviour of the buildings is simulated with frame finite element models; nonlinearities are concentrated in plastic hinges located at the ends of each element (concentrated plasticity) whose moment-curvature law is represented by fibre models. Apart from the buildings themselves, the parameters of the study are the soil type, the presence of pulses in the inputs, the damping and stiffness coefficients of the impact model, the separation between the buildings, and the soil-structure interaction. The performance indices are the maximum inter-storey drift, the absolute acceleration and storey shear force, and the cumulated hysteretic energy. The obtained results highlight the relevance of pounding; the influence of the aforementioned parameters is discussed.