Structural health monitoring is an emerging area of strategic engineering with a great potential for extending the service life of civil infrastructures and reducing their maintenance costs. In spite of the deflection measurement being one of the main parameters for assessing the real state of a bridge, the measurement techniques and the existing deflection transducers often do not respond to the necessities of structural monitoring. Therefore, a novel displacement transducer to measure bridge deflections based on noncontact measurement technique supported by the liquid leveling method was developed. The measurement of bridge deflections is performed using a hydrostatic level position along the structure as an absolute reference and without any external physical reference to the ground. Fiber-optic sensors based on fiber Bragg grating technology are the sensing units of this original bridge deflection transducer. The transducer performance obtained in a set of experimental tests has shown an accurate linear response and a very good behavior under the environmental conditions simulated in a climatic chamber. A field application at the Lezíria Bridge across the Tagus River, Portugal, evinces the ability of the present transducer to be applied in both temporary and permanent structural health monitoring systems with automatic and remote data acquisition.

Currently, long‐term monitoring systems are mandatory for major civil engineering structures such as bridges, tunnels and dams. Generally, they monitor a set of physical, chemical and mechanical parameters in critical sections of the structure by incorporating appropriate sensors. The set of data collected demonstrates great potential in the prevention of damage and contributes to more efficient maintenance of the structures monitored. This work presents the long‐term monitoring system installed on the new Lezíria Bridge over the River Tagus in Portugal. The system was developed to control some aspects of the construction process and to survey the service life of the structure. A set of structural, durability and environmental parameters defining the bridge condition are remotely assessed in real‐time via a fibreoptic network. Aspects such as architecture, installation and functionality of the monitoring system are discussed and the innovative aspects of the implementation are highlighted. In this context, the main goal of this work is to present the long‐term monitoring system of Lezíria Bridge, sharing the experiences, the solutions and the procedures adopted, given their potential usefulness in the implementation of similar projects.

The use of mechanically stabilised earth (MSE) structures is becoming widespread, especially for transportation-related infrastructure. The present study is a contribution to a better understanding of MSE wall structural performance, through the analysis of measurements obtained during the construction of a MSE wall for the A4 Portuguese highway, between Amarante and Vila Real – and the development of a numerical model based on the finite-element method. The monitoring programme and equipment are described. The numerical model was developed using a commercially available finite-element software package together with the Mohr–Coulomb elastoplastic constitutive model for the soils. The numerical model was calibrated against measured data. Finally, a parametric analysis was performed to quantify some of the most significant parameters that influence the general behaviour of the wall.