Case Study of Damage on Masonry Buildings Produced by Tunneling Induced Settlements

This study analyzes the structural response of a group of masonry buildings subjected to real ground movements experienced during the construction of the L9 Metro tunnel in Barcelona, bored by a earth pressure balance machine (EPB) tunnel boring machine (TBM). The studied one-story small dwellings represent a common building typology frequently used in those days in Barcelona's outskirts (more than 1000 were erected). Real settlement profiles are compared with the ones provided by empirical methods, which estimate the shape and the area of the trough according to the ground properties and the volume loss. The first aim of the study is to evaluate the effectiveness of two techniques used to predict damages in buildings resulting from tunneling subsidence: 1) the equivalent beam and its subsequent refinements, and 2) the use of a non-linear finite element (FE) macro-model. The real structural damage presented in the buildings is compared with the predictions given by these two methods. Main model parameters have been determined by means of characterization experiments developed on the site and in the laboratory, thus giving a much higher significance to the analysis. The obtained predictions present a high correspondence with the actual damage registered, particularly in crack patterns and widths.