Dynamical Characterization of Typical Mexican Colonial Churches

Abstract

The dynamic characterization of ancient masonry churches built in the colonial era in Mexico is evaluated by means of a case study. Seismic assessment of old masonry churches is not an easy task, mainly due to the fact that the churches are large structures with complex geometries and built with materials with a highly nonlinear behavior. The case study concerns a typical church in Central Mexico. The aim of the characterization was to develop a methodology suitable for assessing the seismic vulnerability of this type of constructions. The study is based on the so-called complementary analysis approach. Thus, three steps were performed for the needs of assessment: (a) preliminary studies, which include the essential historical information, documentation of materials and geometry through survey of the structure and non-destructive testing; (b) calibration and validation of numerical models, based on the results obtained from the previous step; and (c) dynamic characterization. By combining the results of different types of models and analysis, this approach allows to overcome the complexity of the study of the seismic behavior of ancient masonry structures. The chapter is based on a case study but also provides a very relevant discussion on an issue that has received insufficient attention: the seismic analysis of masonry structures without a box behavior. From the results obtained, it was identified that roof system cannot be considered a rigid diaphragm. The belfry and the roof (dome and vaults) are the most critical elements. The church is very rigid, since the lateral wall drifts are very low. Thus out-of-plane and shear behavior in walls are not critical behaviors in this particular case.