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The masonry building heritage embraces a large variety of structural typologies, including churches, bridges, arenas, theatres, portals, castles, temples, and towers. The structural behaviour of these constructions appears often complex to be understood due to the uncertainties related to the materials and internal geometry. In this paper, a comple...
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... The modal eigenvalue analysis was carried out to determine the free vibrational characteristics of the analytical models [47][48][49] for the Type A and Type B models. Using the adopted material properties as mentioned in Table 4, the results of the modal frequencies for Type A and Type B models are shown in Table 5. ...
The preservation of cultural heritage has been a global concern. In the context of vulnerability assessments and risk reduction strategies studied, historical monument rehabilitation in Nepal has often occurred without a comprehensive damage grade analysis. This paper addresses this gap by presenting a seismic fragility assessment of a two-tier Nepalese pagoda temple, with the Laxmi Narsingha temple as a case study. This pagoda temple features load-bearing brick masonry with timber posts and crossbeams. Comparative finite element (FE) models—one with a masonry-timber interface and one without—were analyzed and subjected to pushover analysis. The failure mechanisms (cracks) in these models revealed distinct behavioral differences. The study further examined the influence and sensitivity of masonry properties on the temple's response quantities through parametric assessments. Furthermore, fragility analysis of the temple's analytical models was done for three performance levels- Immediate Occupancy (IO), Life Safety (LS), and Collapse Prevention (CP). The fragility analysis results indicate that the model with a masonry-timber interface recorded a higher likelihood of exceeding the limit states over the one without interface characteristics counterpart. The study helps to analyze and decide over the selection of a suitable analytical procedure to represent the failure mechanisms exhibited by the pagoda structure.
... Various studies have been conducted on the seismic performances of historical masonry towers (Ivorra et al. 2009;Chavez et al. 2012; Bartoli and Betti 2013;Colapietro and Fiore 2013). Among them, the dynamic characteristics of existing masonry towers have been investigated (D'Ambrisi et al. 2012;Cabboi et al. 2012;Lu et al. 2020;Micelli et al. 2020), and shaking table tests and nonlinear finite element (FE) analyses have been performed to evaluate the seismic performance of typical historical towers (Milani et al. 2017;Xie et al. 2020;Torelli et al. 2020;Hoveidae et al. 2021). Furthermore, the abovementioned studies have shown that the damage assessment and seismic analysis of historical masonry towers are challenging because of their heterogeneous and composite nature (Bartoli et al. 2017). ...
This study assessed the seismic damage to historical masonry towers using a three-dimensional finite element (FE) numerical model. The FE model was validated by comparing the dynamic characteristics and seismic analysis results with experimental data obtained using shaking table tests conducted on a 1/8 scaled tower model. Based on this analysis, a numerical analysis model of the damaged ancient brick masonry tower was established by introducing factors such as initial cracks and inclination, and the damage FE model was validated using experimental data provided by the shaking table tests. Subsequently, the damage index of the wall components were obtained using the modified Park–Ang damage model; these were used to obtain the damage indices of the historical tower floors, which were further used to obtain the overall damage indices of the historical tower. Furthermore, the performance levels of historical towers were proposed, and the damage indices at different performance levels were quantified using various parameters. Finally, the damage to the historical tower model in the shaking table test was analyzed based on the various quantitative results.
... Also, drones provide a relatively accurate and reliable methodology for capturing building images for heritage buildings' conservations. In a recent study to assess the stability and the seismic vulnerability of the bell tower, Micelli & Cascardi (2020) have developed an innovative approach of the drone-based survey to reduce the time-cost expenditure of the structural assessment for a heritage building. As part of emergency disaster response, by using the advancement of deep-learning models for natural disaster surveillance, Mishra et al (2020) developed an autonomous drone for search systems that contains more than 30,000 human instances of different actions. ...
... Briefly, computational modelling strategies used for the structural/seismic assessment of URM buildings can be grouped into continuum and discontinuum-based approaches [13]. Traditional continuum-based models, also referred to as macro-modelling, represent masonry as a homogeneous medium by utilizing averaged constitutive relationships to define nonlocal mechanical properties and are commonly employed in the structural assessment of masonry buildings [10,[14][15][16][17][18][19][20]. Although macro-modelling offers a computationally efficient strategy for analyzing the overall behaviour of the masonry structure, it may not accurately capture the damage localization and crack propagation influenced by the morphological features of the masonry. ...
Unreinforced masonry (URM) walls are common load-bearing structural elements in most existing buildings, consisting of masonry units (bricks) and mortar joints. They indicate a highly nonlinear and complex behaviour when subjected to combined compression–shear loading influenced by different factors, such as pre-compression load and boundary conditions, among many others, which makes predicting their structural response challenging. To this end, the present study offers a discontinuum-based modelling strategy based on the discrete element method (DEM) to investigate the in-plane cyclic response of URM panels under different vertical pressures with and without a damp-proof course (DPC) membrane. The adopted modelling strategy represents URM walls as a group of discrete rigid block systems interacting along their boundaries through the contact points. A novel contact constitutive model addressing the elasto-softening stress–displacement behaviour of unit–mortar interfaces and the associated stiffness degradation in tension–compression regimes is adopted within the implemented discontinuum-based modelling framework. The proposed modelling strategy is validated by comparing a recent experimental campaign where the essential data regarding geometrical features, material properties and loading histories are obtained. The results show that while the proposed computational modelling strategy can accurately capture the hysteric response of URM walls without a DPC membrane, it may underestimate the load-carrying capacity of URM walls with a DPC membrane.
... Grazzini et al. [26] reconstructed multi-temporal 3D models from UAV images to monitor the damage progression of a church throughout a seismic sequence. The created 3D model has also been utilised to visualise damages detected from images [27,28] and create images with specific views (e.g., orthophotos) [8,29]. However, several limitations of stereoscopic photogrammetry techniques can be observed: 1) the insufficient and similar features on building façades may lead to false matching between UAV images, thus reducing accuracy in 3D reconstruction; 2) the 3D reconstruction process is computationally expensive, leading to substantial processing time; 3) the generated 3D point cloud lacks directly link to BIM, and thus manual registration between the point cloud and BIM is generally needed. ...
While Unmanned Aerial Vehicles (UAVs) are increasingly used for building façade inspections, their advantages have not been fully leveraged due to the challenge in gaining a fast and holistic understanding of as-is building conditions from fragmented images. This paper describes a framework to address the problem by registering UAV images into a Building Information Model (BIM) in three phases: (1) Extract position and optical parameters from UAV images to configure virtual cameras in BIM and generate template images; (2) Employ an improved generalised Hough transform (GHT) to extract building façade components with arbitrary shapes; (3) Project UAV images onto an orthophoto and incorporate them into 2D and 3D views. Finally, a Dynamo prototype is developed to automate the process. Computer simulations and field experiments confirmed a mean image-to-BIM registration error of within 21 mm, demonstrating the proposed approach has the potential to facilitate UAV-enabled building façade inspection.
... The accuracy of the DEM simulation of masonry structures is also limited without the brick shapes being accurately modeled. To overcome these challenges, imaging techniques have been recently adopted to capture the ground truth brick geometry (Abu-Haifa & Lee, 2022;Castellazzi et al., 2015;Ioannides et al., 2012;Kassotakis et al., 2020;Loverdos et al., 2021;Micelli & Cascardi, 2020;Truong-Hong et al., 2013). For example, an innovative framework has been developed to use a single masonry image for streamlined image-based DEM modeling (Abu-Haifa & Lee, 2022), but this approach is limited to the modeling of a planar masonry wall. ...
... A large number of studies on seismic assessment of masonry towers have been conducted through numerical modelling, relying either on advanced 3D finite element models (Acito et al. 2014;Ferraioli et al. 2020;Micelli and Cascardi 2020;Preciado 2015;Valente and Milani 2016) or simplified beam models (D'Ambrisi, Mariani, and Mezzi 2012;Kohan, Nallim, and Gea 2011;Riva et al. 1998). To overcome the stated mismatch, calibration of the numerical models is required, so that the numerical frequencies approximate the experimental ones (Bassoli et al. 2018;Gentile and Saisi 2007;Ivorra and Pallarés 2006;Jaishi et al. 2003;Ramos et al. 2010;Torelli et al. 2020). ...
... The study area of cultural heritage conservation is experiencing a contemporary period, thanks to the development of research techniques and digital tools [3]. When technological development processes are monitored, digital photogrammetry has gained a new perspective on the analysis and documentation processes with the development of camera systems together with threedimensional laser scanners [3,[35][36][37]. With the developing technology, alternative approaches to the finite element modeling process of historical buildings should be produced. ...
... The study concluded that the integration of high accuracy photogrammetry into the structural analysis process can be a promising methodology for the assessment and analysis of the behavior of historic buildings. Micelli et al. [36], obtained the model of the tower built in the 14th century with drone-assisted digital photogrammetry. The photogrammetric model was imported to the structural analysis program MIDAS FEA and linear static, linear dynamic, and nonlinear static (thrust) structural analyses were performed on the model. ...
Finite element method (FEM) provides the numerically solving differential equations arising in engineering and mathematical modeling of physical systems. This process begins by determining the assignment of a theoretical node. A node is a single point on a frame, shell, or solid element and each element can be programmed with its location's material and structural data. Programming with the FEM is quite time-consuming for complex geometry such as historical buildings. This study aims to examine a low-cost and time-saving technology to build a FEM model using photogrammetry. In accordance with this aim, classical modeling techniques and photogrammetric modeling techniques were discussed. The results demonstrated that similar values were revealed in stress and deformation values. Consequently, the study emphasizes the potential of photogrammetry technology as an integrated approach for bringing together the disciplines of architecture and engineering that usually require two distinct expertise in analysing the structural behavior of historical buildings.
... These considerations have led to the adoption of isotropic nonlinear models in the analysis of monumental masonry structures. Several research studies that have utilized isotropic smeared crack, damage, and plastic damage models have been conducted successfully on historical masonry structures, including palaces [17][18][19][20], towers [21][22][23][24][25][26] and churches [27][28][29][30][31]. ...
This study describes the seismic assessment of the Archangeloi (Başmelekler) Church in Kumyaka (Sige), Türkiye. The Archangeloi Church is an important religious monument that has survived to the present day from the eighth century. Through field surveys, the structural system, damages and masonry texture were determined. Pushover analysis was performed with OpenSees software, which has an advanced nonlinear analysis capability. The Damage TC3D material damage model with advanced features was used, allowing a more stable and effective application of mixed implicit–explicit analyses. Displacement-based pushover analyses were performed with different control points, and the damage patterns, ultimate strength and strength reductions were obtained effectively. The pushover analysis reflected the structure’s expected behavior, especially its post-ultimate strength and failure patterns, owing to the material damage model’s advanced mixed implicit–explicit capacity. Kinematic analyses were performed to determine the overturning mechanisms. Due to the analysis assumptions and pre-assigned failure mechanisms, lower failure multipliers were obtained with the kinematic analysis than with the pushover analysis. Under seismic loading, the structure did not satisfy the required performance targets. Extensive damage occurred throughout the structure, even at the lowest performance levels. The selected modeling/analysis method and material damage model to determine this church’s structural performance reflect the expected structural behavior.
... Such method typically used laser scanning techniques to obtain the 3D point-cloud model of the test specimen [1][2][15][16][17][18][19][20][21][22][23]. Or used the photogrammetry image-based carry out by unmanned aerial vehicle (UAV) technology to reconstruct the 3D point-cloud model of the structures [24][25]. Based on the 3D point-cloud model, data processing methods are developed to reconstruct the digital geometric model [15][16][17], and to extract the imperfection from the digital geometric model [1][2][18][19][20][21][22][23]. ...
... Flexural mode imperfection 24 wave state. However, the overall geometric imperfections distribution obtained from Keyline is found to be more reasonable, and the mode shape is in agreement with actual expectations. ...
... . It can be concluded that the torsion effect of the cross-section is limited in the doublesymmetrical section (I-shape section). However, for open cross-sections (e.g., C-shaped section, or L-shaped section), the initial torsion imperfection of the specimen cannot be ignored [19,[23][24]. The data processing method developed in this study is also suitable for measuring the initial torsion geometric imperfection of the specimen with open cross-section, and the effect of the initial torsional imperfection on the bearing capacity of steel members can be investigated. ...
Initial geometric imperfections significantly affect the strength and stability of steel members. The traditional modelling method only considers the amplitude of imperfection, which may lead to unreliable results. A novel method and modelling technique for obtaining the full-filled initial geometric imperfection of steel members was proposed in this study. A handled 3D laser scanner was employed to generate 3D point-cloud model, and a computer software of data processing algorithm (3D Pr.) was developed to convert the 3D point-cloud model to actual digital geometric model. After that, such geometric models can be directly imported into general FE software. Compared with the traditional modelling method, a FE model with full-filled initial geometric imperfection can be developed automatically, and the overall and local initial geometric imperfections can be extracted separately. Finally, a total of 27 test results reported by the authors previously were compared against the results determined from two modelling methods. Upon comparison, it was found that the results determined from the new modelling method were close to those values obtained from the experiments (only 1.75% difference), while the traditional modelling method was found to be conservative by 4.11%. The calculation efficiency of new modelling method can be improved by 9.09%, compared to 2 traditional modelling method. It indicated that the new modelling method proposed in this study can closely predict the initial geometric imperfection of steel members.
