Goian – Cerveira Footbridge over the Miño River. Spain - Portugal

<p>The Goián - Cerveira footbridge over the Miño river, result of an international competition held in 2017, will connect the Espazo Fortaleza park in Goián-Tomiño, Spain, and the Castelinho park in Vila Nova de Cerveira, Portugal.</p><p>The proposed footbridge saves a main span of 265m, and is a suspended structure, with two towers located on the riverbanks, avoiding intermediate supports on the riverbed, and only one suspension cable. The towers are located not centered with the axis of the footbridge deck, that adopts a curved layout both in plan and in elevation. The curved layout in plan fits better to the footbridge arrival in both riverbanks, and improves its structural behavior. Indeed, the eccentric location of the suspension cable within the deck generates important horizontal transverse forces, that are supported by the curved deck by behaving as an arch. This configuration is also very convenient for supporting and controlling wind loads. It is a classic bridge type -suspended bridge- but with a singular configuration due to the curved layout of the deck and its arc-like behavior.</p><p>The result is a very subtle and slender structure, a “line over the Miño river”, that highly preserves the environmental values of the river and the landscape.</p>

“Himalayan Bridge”: A New Unstable Suspended Bridge to Investigate Rodents' Venturesome Behavior

While both risk-taking and avoidant behaviors are necessary for survival, their imbalanced expression can lead to impulse-control and anxiety disorders, respectively. In laboratory rodents, the conflict between risk proneness and anxiety can be studied by using their innate fear of heights. To explore this aspect in detail and investigate venturesome behavior, here we used a “Himalayan Bridge,” a rat-adapted version of the suspended wire bridge protocol originally developed for mice. The apparatus is composed of two elevated scaffolds connected by bridges of different lengths and stability at 1 m above a foam rubber-covered floor. Rats were allowed to cross the bridge to reach food, and crossings, pawslips, turnabouts, and latencies to cross were measured. Given the link between risky behavior and adolescence, we used this apparatus to investigate the different responses elicited by a homecage mate on the adolescent development of risk-taking behavior. Thus, 24 wild-type (WT) subjects were divided into three different housing groups: WT rats grown up with WT adult rats; control WT adolescent rats (grown up with WT adolescents), which showed a proclivity to risk; and WT rats grown up with an adult rat harboring a truncated mutation for their dopamine transporter (DAT). This latter group exhibited risk-averse responses reminiscent of lower venturesomeness. Our results suggest that the Himalayan Bridge may be useful to investigate risk perception and seeking; thus, it should be included in the behavioral phenotyping of rat models of psychiatric disorders and cognitive dysfunctions.

Sensitivity Investigation on the Pressure Coefficients Non-Dimensionalization

The scaling of large structures to investigate their aerodynamics in wind tunnels is a common and robust procedure to estimate important magnitudes, including pressure coefficients. Different aspects can affect the estimation of pressure coefficients; four examples are the non-dimensionalization, blockage, non-stationarity, and non-Gaussianity of the wind tunnel velocity. This paper shows the variability of pressure coefficients due to these four aspects for the case study of a closed box section of a suspended bridge. It was estimated that the pressure coefficients of similar pressure taps vary significantly due to different sets of wind velocity time history used to non-dimensionalize the wind tunnel pressures. In addition, the stationarity of the wind velocity process was not confirmed for all wind velocity sets and the non-Gaussianity of the wind velocity time history was confirmed.

Innovative Suspended Superstructure for the Retrofitting of a Steel Truss Railway Bridge

The bridge in Poggio Renatico crossing the Reno river on the railway line between Bologna and Ferrara, consists of steel decks supported by masonry abutments and piers, while foundations and pier caps are made of reinforced concrete. After the 2012 Emilia Earthquake and accounting for the fluvial erosion below the piers foundations, a structural assessment of the bridge was carried out in accordance with to the current Italian rules. Although a sufficient structure capacity against the actual transit loads resulted, the bridge showed some inadequacies with respect to the load models provided by both the national standard for constructions and the guidelines of the Italian railway network company. The retrofitting project consists of an improvement of the structural capacity of all the elements: girders, piers and abutments. An innovative retrofitting solution provides for the strengthening of the existing decks through a suspension system of cables anchored to steel towers standing on both abutments and piers and creating a kind of suspended bridge. The retrofitting is compatible with the normal scheduled interruptions of the rail traffic thereby reducing the maintenance costs of the railway system. The structural solution represents a model easily replicable to solve analogous situations along the railway network.