Laboratory testing and finite element simulation of the structural response of an adobe masonry building under horizontal loading

摘要

This paper is concerned with the calibration and validation of a numerical modelling approach for adobe masonry buildings under horizontal loading. The paper first reviews the state-of-the-art in experimental and computational research of adobe structures and then presents results obtained from monotonic lateral loading laboratory tests on a 1:2 scaled unreinforced adobe masonry building. Through the experimental investigation conducted, useful conclusions concerning the initiation and propagation of cracking failure are deduced. In addition, damage limit states at different levels of deformation are identified. Experimental results verify that the response of adobe structures to horizontal loads is critically affected by weak bonding between the masonry units and mortar joints and by lack of effective diaphragmatic function at roof level. Based on experimental material data, a 3D finite element (FE) continuum model is developed and calibrated to reproduce the test structure's force-displacement response and mode of failure. An isotropic damaged plasticity constitutive law is adopted for the numerical simulation of adobe masonry and the use of appropriate modelling parameters is discussed. The FE analyses carried out reveal that the global structural behaviour is primarily influenced by the tensile response assigned to the homogenized masonry medium. Results show that, despite its generic limitations and simplifications, FE continuum macro-modelling can approximate the structural behaviour of horizontally loaded adobe masonry construction with sufficient accuracy. In order to enrich the available information on the seismic behaviour of adobe structures, the calibrated FE model is also subjected to time-history analysis using an accelerogram recorded during a real earthquake.