1,720,988 research outputs found
Many-to-Many Metrics: A New Approach to Evaluate the Performance of Structural Damage Detection Networks
No full textIn the last years, Computer Vision and Deep Learning techniques have proved to be useful in supporting structural inspections of buildings and civil infrastructures. Particularly, in the case of post-disaster structural safety assessment, automated damage detection algorithms can accelerate the analysis of survey images and thus contribute to a fast screening of impacted areas. The identification of the various types of damage can be seen as a special case of object detection in which the goal is to identify sub-parts of a large object (e.g., cracks on a building). However, in this scenario, traditional evaluation metrics for object detection tend to underestimate the actual performance of the detector, since they considered a one-to-one match between a ground-truth box and a predicted box. Such approach could be sub-optimal for damage detection: for example, a crack can be labeled as a single entity in the ground truth but detected as two small cracks in inference or vice versa. To compensate this issue and better asses the performance of the detector, we introduce a new set of metrics called Many-to-Many. We tested these metrics using a YOLO network on two datasets containing images of damaged bridges and civil structures, and we collected evidence of an improved evaluation capability
Performance of unreinforced stone masonry buildings during the 2010/2011 Canterbury earthquake swarm and retrofit technique for their seismic improvement
No full textPresents a post-earthquake assessment and building damage statistics for unreinforced stone masonry buildings in the city to document the performance of the structures. Gives details on typical building characteristics and on failure modes observed. Talks about damage mechanisms in stone masonry buildings and churches and retrofit interventions
Pushover analysis of unreinforced masonry buildings with different levels of diaphragm stiffness
No full textNumerical Simulation of Shaking Table Tests on Full-Scale Stone Masonry Buildings
No full textBased on the outcomes of a recent experimental project addressing unreinforced stone masonry undertaken at the European Centre for Training and Research in Earthquake Engineering, the seismic response exhibited by two full-scale building prototypes during shaking table tests was simulated according to an existing equivalent frame modeling approach involving nonlinear macroelements. Given the use of different strengthening solutions, the two building specimens strongly differed in the in-plane stiffness of their timber floors and roof diaphragms. This article addresses several issues concerning numerical modeling of the seismic response of this type of masonry construction, particularly its effect upon assessing the global response of the discretization and geometry of the equivalent frame model and upon definition of model parameters based on tests of material characteristics and lateral response of structural members. Even in the case of flexible diaphragms, the results of pushover analysis of the calibrated models provided a fair approximation in terms of both envelope curve and damage pattern. The results of time history analysis accounting for cumulative damage indicate good simulation in terms of hysteretic response as well
Equivalent-frame macro-element simulation of shaking table tests on unreinforced stone masonry buildings with strengthening interventions
No full textNumerical simulation of the experimental seismic response of unreinforced stone masonry buildings with stiffened diaphragms and improved wall-to-diaphragm connections
No full textValutazione della vulnerabilità sismica di edifici esistenti in muratura: il complesso dell'ex monastero di San Felice a Pavia
No full textDamage Assessment of Unreinforced Stone Masonry Buildings After the 2010–2011 Canterbury Earthquakes
No full textThe sequence of earthquakes that has affected Christchurch and Canterbury since September 2010 has caused damage to a great number of buildings of all construction types. Following post-event damage surveys performed between April 2011 and June 2011, an inventory of the stone masonry buildings in Christchurch and surrounding areas was carried out in order to assemble a database containing the characteristic features of the building stock, as a basis for studying the vulnerability factors that might have influenced the seismic performance of the stone masonry building stock during the Canterbury earthquake sequence. The damage suffered by unreinforced stone masonry buildings is reported and different types of observed failures are described using a specific survey procedure currently in use in Italy. The observed performance of seismic retrofit interventions applied to stone masonry buildings is also described, as an understanding of the seismic response of these interventions is of fundamental importance for assessing the utility of such strengthening techniques when applied to unreinforced stone masonry structures.AM - Accepted Manuscrip
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