A hysteretic model for “frontal” walls in Pombalino buildings

Abstract

The heritage value of the mixed wood-masonry 18th century Pombalino buildings of downtown Lisbon is recognized both nationally and internationally. These buildings have a three-dimensional timber structure composed of wooden floors, stairs and walls intended to provide better seismic resistance and are enclosed by masonry walls. These interior wooden walls are called “frontal” walls and their behaviour under cyclic loading has scarcely been studied. This report describes an experimental programme to determine the hysteretic behaviour of these “frontal” walls, using static cyclic shear testing with imposed displacements. Two tests were conducted on two identical real-size walls. A new hysteretic model for the cyclic behaviour of these “frontal” walls in Pombalino buildings is presented and calibrated based on the experimental results. The hysteresis model was developed based on a minimum number of path following rules that can reproduce the response of the wall tested under general monotonic or cyclic loading. The model is constructed using a series of exponential functions and linear functions. The nine parameters in this model capture the nonlinear hysteretic response of the wall. The hysteretic behaviour of such walls subjected to cyclic loading exhibit high nonlinear force-displacement responses and high ductility.