Small-scale shake table tests of 2D blocky assemblies: design, experimental testing, and camera-based block tracking

Details

Supervisors

Saraiva Esteves Pacheco De Almeida, João ; Godio, Michele

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil des constructions, à finalité spécialisée

Abstract

In recent years, the world has witnessed a rise in the frequency of natural disasters, largely attributed to increasing greenhouse gas emissions. Among these disasters, earthquakes represent the most devastating one, resulting in human casualties and extensive material damage. Unreinforced masonry (URM) is the most commonly used construction materials around the world thus it is particularly important to study and understand its behavior under seismic conditions. The advancement of earthquake engineering plays a crucial role in assessing existing structures and designing resilient new ones. The main objective of this thesis is to contribute to the knowledge and understanding of 2D small scale dry-stacked masonry assemblies subjected to earthquake loading. The tests carried out in this thesis hold significant value as they represent the first experimental verification for this particular type of structure. Indeed, these tests serve a crucial role in validating the precision and reliability of the numerical simulations as documented in prior research papers. This validation is achieved by comparing acceleration values and rocking phenomenon through both numerical and experimental testing methodologies. The testing process involves crafting blocks through laser-cut wooden pieces, assembling them into hollow structures, and filling them with coarse sand. The investigation continues by assessing the capabilities of the brand new shake table, known as ATOM, to determine the critical acceleration causing a rocking phenomenon in these assemblies, ultimately leading to collapse. Verification of the recorded acceleration values is achieved through a comparison between the data from the shake table software and those obtained from an external accelerometer placed on the structure. Beyond shake table testing, this thesis employs a multi-faceted IT approach that includes image undistortion, extraction, and analysis. By tracking the positions of pairs of targets affixed to each full brick throughout the experiments, a dedicated tracking code computes the actual displacements of the bricks during the entire testing procedure. These displacement data are then used to accurately represent the behavior of each structure under dynamic loading conditions.