scholarly journals Algorithm to Estimate the Capacity Reserve of Existing Masonry Arch Railway Bridges

2022 ◽  
Vol 12 (2) ◽  
pp. 756
Author(s):  
Francesca Brighenti ◽  
Luca Possidente ◽  
Daniele Zonta

Most railway masonry arch bridges were designed according to codes that predate the 1950s; therefore, assessing their load-carrying capacity to comply with current codes is of the utmost importance. Nonetheless, acquiring the necessary information to conduct in-depth analyses is expensive and time consuming. In this article, we propose an expeditious procedure to conservatively assess the Load Rating Factor of masonry arch railway bridges based on a minimal set of information: the span, rise-to-span ratio, and design code. This method consists in applying the Static Theorem to determine the most conservative arch geometry compatible with the original design code; assuming this conservative geometrical configuration, the load rating factor, with respect to a different design load, is estimated. Using this algorithm, a parametric analysis was carried out to evaluate the Load Rating Factor of old arch bridges in respect of the modern freight load of the Trans-European Conventional Rail System, for different spans, rise-to-span ratios, and original design codes. The results are reported in easy-to-use charts, and summarized in simple, practical rules, which can help railway operators to rank their bridges based on capacity deficit.

Author(s):  
Emanuele Reccia ◽  
Antonella Cecchi ◽  
Gabriele Milani

The problem of masonry arch bridges load carrying capacity is studied by means of a coupled FEM/DEM 2D approach. The numerical model relies into a triangular discretization of the domain with embedded crack elements that activate whenever the peak strength is reached. The proposed approach can be regarded as a combination between Finite Elements allowing for the reproduction of elastic strain into continuum and DEM, suitable to model frictional cohesive behavior exhibited by masonry structures even at very low levels of external loads. The aforementioned numerical approach is applied to masonry arch bridges interacting with infill. A preliminary validation of the procedure is addressed for the prediction of the masonry arches limit state behavior where the stones are supposed infinite resistant and plastic hinges can occur exclusively on mortar joints, modeled as cohesive frictional interfaces. The sensitivity of the infill role varying mechanical properties of the infill is extensively discussed.


Arch bridges ◽  
1995 ◽  
pp. 449-458 ◽  
Author(s):  
Paolo Faccio ◽  
Paolo Foraboschi ◽  
Enzo Siviero

2020 ◽  
Vol 60 (4) ◽  
pp. 349-358
Author(s):  
Marek Vokál ◽  
Michal Drahorád

The article deals with an analysis of railway masonry arch bridges. Typical attributes of these bridges are pointing loss and backfill. Therefore, the material - masonry - behaviour can be described only by a non-linear stress-strain diagram, mainly because of low or no tensile strength. The load carrying capacity, which is one of the main parameters when assessing the bridge, is a non-linear problem with many inputs, such as properties of backfill and masonry, backfill depth and geometry of the arch. Some of these parameters can be obtained by a diagnostic survey or from archival documentation. Some of these parameters impact the calculation greatly and some negligibly. The identification of key parameters, which must be stated by the diagnostic survey, is the goal of this article.


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