Advances in the production of optical fibers made possible the recent development of innovative sensing systems for the health monitoring of civil structures. The main reasons for this development are the reduced weight and dimensions of fiber optic sensors, the strong immunity to electromagnetic interference, the improved environmental resistance and the scale flexibility for small-gauge and long-gauge measurements. These systems can provide high-resolution and measurement capabilities that are not feasible with conventional technologies. In addition, they can be manufactured at a low cost and they offer a number of key advantages, including the ability to multiplex an appreciable number of sensors along a single fiber and interrogate such systems over large distances. For these reasons, it is evident that fiber optic sensors will change the instrumentation industry in the same way fiber optics has revolutionized communications. This paper provides an overview of the intensity modulated and spectrometric...

The main objective of a bridge manager is to find the best maintenance plan for a group of bridges over a prescribed time horizon. The bridge manager usually faces conflicting objectives, as maintenance plans resulting in safer and less deteriorated structures also lead to higher costs. In general, the problem is posed as a deterministic single-objective optimization where cost is minimized keeping performance above predefined thresholds. However, single-objective optimization results in only one optimal solution that does not provide the advantages of considering other objectives and constraints. In addition, the effects of uncertainties are not taken into account or are included in a very simplified way. The bridge manager obtains, in this way, only one deterministic optimum maintenance plan, and not a set of different probabilistic maintenance solutions from which the best, for each particular situation, can be chosen. In this paper, a full probabilistic multiobjective approach to bridge maintenance co...

A general step-by-step model for the nonlinear and time-dependent analysis of reinforced concrete, prestressed concrete, and composite steel-concrete planar frame structures is presented. The model can simulate segmental construction processes such as changes in either the longitudinal and cross-sectional geometry or in the properties of the materials; the placement or removal of elements, prestressing tendons, and stays; and modifications in the internal and external boundary conditions. The nonlinear time-dependent materials properties, the structural effects of the delayed deformations, and the second-order effects are also considered in the structural analysis under loads and imposed deformations. The model can trace structural response during the construction of the structure and throughout its service life. Consideration of the geometric and material nonlinearities allows the structural response to be traced through the elastic, cracked, and ultimate load level, providing valuable information about ...