دانلود رایگان مقاله انگلیسی مقایسه حالت های شکست در سطح و خارج از سطح از پل های قوس سنگی با استفاده از تحلیل مخروطی - الزویر 2019

ABSTRACT

This research aims to provide a better understanding of the structural behavior of masonry arch bridges using advanced modeling strategies. Two main contributions are achieved in this article; first, triggering mechanisms for the out of plane failure of spandrel walls are established; second, the influence of soil backfill on the behavior and strength of the bridges is presented through a comprehensive parametric study. Here, masonry arch bridges are modeled using a discontinuum approach, composed of discrete blocks, including also a continuum mesh to replicate infill material, adopting a framework of discrete element modeling. The equations of motion for each block are solved by an explicit finite-difference method, using the commercial software 3DEC. The results of the preliminary analyses are compared with analytical solutions and limit state analysis for validation purposes. Different arch bridge models, representing common geometrical properties in the northwest Iberian Peninsula are analyzed. Transverse effects, damage patterns and collapse mechanisms are discussed under different types of loading. The analysis demonstrated the severe capacity reduction due to spandrel wall failures and the importance of soil backfill in results, only possible by taking advantage of the performed numerical modeling strategy.

Conclusions

This research provides a better understanding of the complex behavior of masonry arch bridges by considering the influence of the backfill properties, contact between backfill and masonry, type of vehicle load assumed and spandrel wall vulnerability. First, the discontinuous and nonlinear characteristics of masonry bridges are simulated via a mixed discrete-continuum modeling strategy by conducting parametric analysis with a simplified approach, namely computational limit state analysis. A good agreement is found between the limit state analysis and the detailed numerical model for a shallow arch bridge with short span. In-plane collapse mode is obtained where masonry arch barrel collapsed due to plastic hinging mechanism. However, it is concluded that to understand the full structural response of masonry arch bridges, three-dimensional models are needed, which has the capability of simulating the transversal deflections, of the spandrel walls.