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Application of a modular bridge weigh-in-motion system on an orthotropic bridge deck
Published in Joan-Ramon Casas, Dan M. Frangopol, Jose Turmo, Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability, 2022
J.D. Rodenburg, S.H.J. van Es, J.H. Paulissen, M.P. de Bakker, S.T. Hengeveld
The proposed BWIM system requires strain measurements as an input. Depending on the amount of sensors and location of the sensors, different information can be retrieved from the BWIM system. For the cost optimized product a smaller set of sensors can be used, A typical application scenario of this cost optimized product is the implementation of the developed BWIM software for a set of sensors that is already present at a bridge for a different investigation. For the output optimized product, a sensor plan needs to be developed to make optimal use of the BWIM system. For example, for the identification of individual axles, sensors should be placed on elements with short influence lines. An influence line denotes the (strain) response of a structure at a specific location as afunction of the location of the load. For orthotropic steel decks, a typical location for these sensors are troughs or stiffeners below the deck plate. For the identification of the total weight of lorries, the requirement with regard to the influence line length can be somewhat relaxed, such that for example the cross girder or even the main bearing structure becomes fit for the placement of sensors. For the determination of the velocity of lorries, sensors should be located at two known longitudinal locations. Figure 1 provides a schematic example of a sensor plan for an orthotropic bridge deck for an output optimized BWIM system. The application of each sensor is elaborated upon in section 2.1.
Ancient sizing rules and limit analysis of masonry arches
Published in Pere Roca, Paulo B. Lourenço, Angelo Gaetani, Historic Construction and Conservation, 2019
Pere Roca, Paulo B. Lourenço, Angelo Gaetani
In case the arch is subjected to a vertical point load as illustrated in Figure 5.17, the thrust line can be easily calculated according to the procedure described in Figure 5.14. The external load can be simply treated as an extra vector in the polygon of forces. It is worth noticing that, according to influence line analysis, the arch exhibits the lowest capacity when the external load acts at about a quarter span. For the sake of clarity, an influence line is the graphical representation of a function at a specific point on a structure caused by a unit load placed at any point along the structure. In this case, the function is the arch capacity.
Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
An influence line is a plot of the variation of a response function (such as a reaction, an internal shear, an internal moment, etc.) at a given point of a two-dimensional structure when a unit load is applied at different locations on the structure. An influence surface is a collection of influence lines plotted for a three-dimensional structure. Influence lines can be constructed using either the quantitative method, in which the desired response function at a given point of the structure is computed repeatedly when a unit
Determination of load distribution factors of steel–concrete composite box and I-girder bridges using 3D finite element analysis
Published in Australian Journal of Structural Engineering, 2018
S. J. Fatemi, A. H. Sheikh, M. S. Mohamed Ali
To find the most critical location where the moving loads elicited the maximum stress resultants within the bridge, influence lines are used. To find these critical points, the set of concentrated loads are placed at different positions, one of which is the point at which the influence line contacted the peak ordinate. Once the critical location of moving loads is determined, the maximum shear force and bending moment are calculated.