Geomatics’ procedures and dynamic identification for the structural survey of the church of ‘San Juan Bautista de Huaro’ in Perú

This paper presents the feasibility of combining geometrical survey and in-situ non-destructive testing for the structural assessment of historical earthen constructions, which has typically difficult and non-documented geometries, unknown and highly variable materials, not visible damage states, and non-well de-fined boundaries and diaphragm conditions. Particularly, this paper presents the results of geometrical and structural surveys that are being carried out in the church ‘San Juan Bautista de Huaro’ in Cusco, Perú, as part of an ongoing research aiming at assessing its seismic vulnerability. The church dates back to the 17th Century and represents a typical Andean adobe church. Regarding to geometry, novel techniques such as laser scan-ning and photogrammetry from drones were successfully integrated to generate an accurate 3D reconstruc-tion, and a numerical model of the building for seismic analysis. This numerical model was preliminary cali-brated considering experimental results from operational modal analysis tests. The calibration process showed the importance of considering the connection elements in the numerical model, as well as allowed a prelimi-nary assessment of material properties.The authors would like to acknowledge the Pontificia Universidad Católica del Perú PUCP and its funding office DGI-PUCP (project 171-2015) for providing funds to the project within which this work was developed and the Peruvian Science and Technology Program (Innóvate Peru) for their financial support on the acquisition of the equipment used (Project 128-FINCYT-ECL-2014). The second and third authors gratefully acknowledge CONCYTEC for the scholarship in support of graduate studies

Surveying and Three-Dimensional Modeling for Preservation and Structural Analysis of Cultural Heritage

Dense point clouds can be used for three important steps in structural analysis, in the field of cultural heritage, regardless of which instrument it was used for acquisition data. Firstly, they allow deriving the geometric part of a finite element (FE) model automatically or semi-automatically. User input is mainly required to complement invisible parts and boundaries of the structure, and to assign meaningful approximate physical parameters. Secondly, FE model obtained from point clouds can be used to estimate better and more precise parameters of the structural analysis, i.e., to train the FE model. Finally, the definition of a correct Level of Detail about the three-dimensional model, deriving from the initial point cloud, can be used to define the limit beyond which the structural analysis is compromised, or anyway less precise. In this work of research, this will be demonstrated using three different case studies of buildings, consisting mainly of masonry, measured through terrestrial laser scanning and photogrammetric acquisitions. This approach is not a typical study for geomatics analysis, but its challenges allow studying benefits and limitations. The results and the proposed approaches could represent a step towards a multidisciplinary approach where Geomatics can play a critical role in the monitoring and civil engineering field. Furthermore, through a geometrical reconstruction, different analyses and comparisons are possible, in order to evaluate how the numerical model is accurate. In fact, the discrepancies between the different results allow to evaluate how, from a geometric and simplified modeling, important details can be lost. This causes, for example, modifications in terms of mass and volume of the structure

Close-Range Sensing and Data Fusion for Built Heritage Inspection and Monitoring - A Review

Built cultural heritage is under constant threat due to environmental pressures, anthropogenic damages, and interventions. Understanding the preservation state of monuments and historical structures, and the factors that alter their architectural and structural characteristics through time, is crucial for ensuring their protection. Therefore, inspection and monitoring techniques are essential for heritage preservation, as they enable knowledge about the altering factors that put built cultural heritage at risk, by recording their immediate effects on monuments and historic structures. Nondestructive evaluations with close-range sensing techniques play a crucial role in monitoring. However, data recorded by different sensors are frequently processed separately, which hinders integrated use, visualization, and interpretation. This article’s aim is twofold: i) to present an overview of close-range sensing techniques frequently applied to evaluate built heritage conditions, and ii) to review the progress made regarding the fusion of multi-sensor data recorded by them. Particular emphasis is given to the integration of data from metric surveying and from recording techniques that are traditionally non-metric. The article attempts to shed light on the problems of the individual and integrated use of image-based modeling, laser scanning, thermography, multispectral imaging, ground penetrating radar, and ultrasonic testing, giving heritage practitioners a point of reference for the successful implementation of multidisciplinary approaches for built cultural heritage scientific investigations

Non-destructive means and methods for structural diagnosis of masonry arch bridges

Within the precepts defended by the International Charter of Kraków, this paper aims at presenting a fully non-destructive multidisciplinary approach able to characterize masonry bridges at three different levels: i) geometrical level; ii) material level and; iii) structural level. To this end, this approach integrates the terrestrial laser scanner, the sonic and impact-echo methods, the ground penetrating radar and the multichannel analysis of surface waves. All these data are combined with reverse engineering procedures, allowing the creation of suitable as-built CAD models for advanced numerical simulations. Then, these numerical models are contrasted and updated through the data provided by the ambient vibration tests. To validate the methodology proposed in this paper, the Roman bridge of Avila was used as study case. This bridge shows a complex mixture of constructive techniques (masonry, cohesive material, Opus Caementicium and reinforced concrete). Thus, the numerical model was considered for performing predictive structural analysis.Junta of Castilla y León | Ref. SA075P1

Automated calibration of FEM models using LiDAR point clouds

In present work it is pretended to estimate elastic parameters of beams through the combined use of precision geomatic techniques (laser scanning) and structural behaviour simulation tools. The study has two aims, on the one hand, to develop an algorithm able to interpret automatically point clouds acquired by laser scanning systems of beams subjected to different load situations on experimental tests; and on the other hand, to minimize differences between deformation values given by simulation tools and those measured by laser scanning. In this way we will proceed to identify elastic parameters and boundary conditions of structural element so that surface stresses can be estimated more easily.Ministerio de Interior | Ref. SPIP2017-02122Ministerio de Economía, Industria y Competitividad | Ref. EUIN2017- 87598Ministerio de Educación, Cultura y Deporte | Ref. CAS15/00126Xunta de Galicia | Ref. ED431C2016‐03