A Comparative Study Between WMMS and TLS for the Stability Analysis of the San Pedro Church Barrel Vault by Means of the Finite Element Method

Abstract

<p><strong>Abstract.</strong> Stability of masonry constructions is highly conditioned by the geometric disposition of its elements due to its low tensile strength and great compressive mechanical properties. Under this framework, this paper attempts to evaluate the suitability of a wearable mobile mapping solution, equipped in a backpack and based on the well-known simultaneous location and mapping paradigm, for the structural diagnosis of historical constructions. To evaluate the suitability of this device, the structural analysis obtained is compared with a high precision terrestrial laser scanner, which is considered as ground truth. The Romanesque church of San Pedro (Becerril del Carpio, Spain) was selected as a study case. This construction, initially conceived in the XIII<sup>th</sup> century, has experimented in the past a soil settlement promoting the leaning of the north wall, several plastic hinges in its barrel vault and a visible geometrical deformation. The comparison of both techniques was carried out at different levels: i) an evaluation of the time needed to obtain the point cloud of the church; ii) an accuracy assessment based on the comparison of a terrestrial network using artificial spheres as checkpoints and; iii) an evaluation of the discrepancies, in terms of safety factor and collapse topology, found during the advance numerical evaluation of the barrel vault by means of the finite element method. This comparison places this wearable mobile mapping solution as an interesting tool for the creation of advanced numerical simulations to evaluate the structural stability of historical constructions.</p>

An historical building information modelling approach for the preventive conservation of historical constructions: Application to the Historical Library of Salamanca

“…Then, the 3D point cloud is created by applying the Simultaneous Location and Mapping algorithm (SLAM) [16]. According to di-Filippo et al [14] and Sánchez-Aparicio et al [17], this system is ten time faster than laser scanning procedures, providing accuracies that range from 1 to 3 cm.…”

Automatic Point-Cloud Registration for Quality Control in Building Works

“…MLS allow the generation of 3D models in a unique acquisition, with the direct result of a single point cloud, consequently with one coordinate system [21,22]. However, the guarantee of metric quality of the 3D models depends on the knowledge of the trajectory of the MLS, which is a complicated task in indoor scenes due to the low coverage of the GNSS signal.…”

“…Providing the highest precision of TLS compared to some MLS, TLS has been used for quality control of built environments in repeated occasions, in combination with artificial referencing systems such as artificial targets for the semi-automatic registration of the different point clouds acquired [22]. This requires the intervention of the user in some tasks, especially in the planning of the acquisition and the registration of point clouds into the same coordinate system.…”

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)

“…The studies carried out by Fillipo et al [19]; Barba at al. [20] or Sánchez-Aparicio et al [21] highlights its efficiency, making it possible to minimize in around 10 times the effort required for digitalizing this scenario by means of a static laser scanner. Inside the different MMSs available nowadays, the wearable mobile mapping solutions (WMMS) are one of the most used.…”

“…Basically, these devices are adapted to be easily carried by a person, making it possible to digitalize a scenario simply by walking. Its flexibility allows one to digitalize a wide variety of Cultural Heritage (CH) scenarios, which are commonly characterized by the presence of complex and narrow spaces [20][21][22][23], or even large surfaces [18,19]. Barba et al [20] present a work on which a WMMS is used in the inner part of the Chapel of the Holy Shroud with the presence of narrow spaces.…”