Three-dimensional discrete element modelling of rubble masonry structures from dense point clouds

Abstract

This paper presents a framework for the three-dimensional structural analysis of full scale, geometrically complex rubble masonry structures from point clouds generated from Structure-from-Motion photogrammetry or terrestrial laser scanning. According to the method, a point-based voxelization algorithm was adopted, whereby a dense point cloud was down-sampled into equidistant points, bypassing the need for conventional intensive processes, such as watertight mesh conversion, to obtain the geometric model of the rubble masonry for structural analysis. The geometry of the rubble masonry structure was represented by a sum of hexahedral rigid blocks (voxels). The proposed "point cloud to structural analysis" framework was implemented to assess the structural stability of the southwest leaning tower of Caerphilly Castle in Wales, UK. Simulations were performed with the three-dimensional computational software 3DEC, based on the Discrete Element Method (DEM) of analysis. Each voxel of the rubble masonry was represented as a rigid, distinct block while mortar joints were modelled as zero thickness interfaces which can open and close depending on the magnitude and direction of the stresses applied to them. The potential of the automated procedure herein proposed has been demonstrated to quantitatively assess the three-dimensional mechanical behaviour rubble masonry structures and provide valuable information to asset owners in relation to the structural health condition of assets in their care.

Dynamic Characterization of a Reinforcement Rammed Wall for the Earthen Ruins

“…e numerical modelling of masonry structure has been investigated by many researchers [25,26]. Meanwhile, the cloud map is applied to analysis the mechanical properties, which is widely used in masonry structures [27]. In the paper, the simplified numerical model was determined by the aerial survey carried out by direct method.…”

Integration of a Wearable Mobile Mapping Solution and Advance Numerical Simulations for the Structural Analysis of Historical Constructions: A Case of Study in San Pedro Church (Palencia, Spain)

“…According to this, a proper survey and building mapping is required for an adequate numerical simulation, demanding the proper integration of different approaches coming from the geoinformatics. This discipline is able to provide a set of remote sensing approaches, such as static terrestrial laser scanning or photogrammetry (especially by means of the structure from motion approach), that can create as-built CAD models [2,3,[9][10][11]. These methods allow one to digitalize historical structures in form of point clouds.…”

Photogrammetric Process to Monitor Stress Fields Inside Structural Systems

“…Other methods, such as the use of LIDAR, have also been proposed in the literature. Works such as [49][50][51] used these techniques to inspect structures and monitor deformation. These methods showed good results.…”