Old masonary tower analysis visual inspection, NDT, and macro-modeling

Abstract

A comprehensive analysis was conducted on a 106-year-old masonry tower to assess its response to gravitational forces and wind effects. Various techniques, including visual inspection, non-destructive testing, and finite element analysis (FEA), were employed in this study. Visual inspection played a vital role in evaluating the Tower’s exterior and interior components, aiming to detect signs of damage or wear at any level and comparing them to the analyzed model. Dimensioned and assembled drawings were utilized to create a detailed 3D finite element model, employing the Ansys Workbench's macro and homogeneous modeling techniques. Non-destructive testing was carried out on multiple structural parts of the tower, using techniques, such as the rebound hammer and ultrasonic pulse velocity tests, to gather the mechanical properties of the stone and brick masonry. These properties were incorporated into the finite element model to evaluate the Tower's structural responses during analysis. The tower's structural response under gravitational forces was determined using standard code regulations and guidelines, and stress and strain responses were compared to the actual structural morphology observed during the inspection. The highest stress was found in the stone elements between the connection of the dome and the drum on the second floor. Furthermore, the tower’s response to wind, including stress and deformation, was thoroughly examined at the same location, revealing the maximum response under gravity loading. This study pinpointed critical and weak areas that require retrofitting and strengthening using modern techniques to safeguard these monumental historical structures for future generations. The combined use of visual inspection, non-destructive testing, and finite element analysis proved to be an effective approach in assessing the response of the 106-year-old masonry tower to gravity loading and wind effects.