One of the most important controlling parameters in bridges are the vertical displacements. Measuring deflections is not only valuable at the early stages of the construction, but during the service lifetime of the structure also. Furthermore, vertical displacements are one of the most important indicators of the healthy state of the bridges among other structural health monitoring parameters used in the assessment of the structural response of the bridges and for foreseeing eventual damage or deterioration issues.
Bridges are often placed over watercourses or over accidentally terrain and normally load tests are carried out before starting its use with the purpose of evaluating the structural response. Measuring vertical displacements are always a challenge and many technics have been developed during the past few years. The present paper introduces a new system based on the use of LVDTs that enables the measurement of vertical displacements in structures when the access to reference points are limited. Also, this system offers a simple application and can be easily placed on site for measuring vertical displacements with both high sampling frequency rates and resolution
