It connects science facilities (Icahn Lab with Jadwin Hall and new Chemistry building) as well as west-side dormitories with athletics facilities. The bridge overall design was made by world renowned bridge designer from Switzerland Christian Menn. HNTB Corporation performed detailed design and Turner Construction Company is the main contractor. Supervision and coordination has been carried out by the representatives from the Office of Design and Construction of Princeton University. Streicker Bridge consists of main span and four approaching ramps, so-called legs. Structurally, the main span is a deck-stiffened arch and the legs are curved continuous girders supported by steel columns. Legs are horizontally curved and the shape of the main span follows the curvature. The arch is built of steel while the main deck and legs are built of reinforced post-tensioned concrete. The SHM of Streicker Bridge is a long-term project and it will be realized in several phases. The initial phase consists of instrumentation of main span and south-east leg. The instrumentation of main span was completed on August 14, 2009 with two fiber-optic sensing technologies: Discrete Fiber Bragg-Grating (FBG) long-gage sensing technology (average strain and temperature measurements); truly distributed sensing technology based on Brillouin Optical Time Domain Analysis (average strain and temperature measurements). The sensors were embedded in concrete during the construction.
Aim of monitoring:
SHM Lab decided to instrument the bridge with various sensors, and to transform it into an on-site laboratory for various research and educational purposes. The main aims of the instrumentation are to face the following challenges related to SHM: Education gap. In spite of its importance, the culture on SHM is not yet widespread. It is often considered as an accessory activity that does not require specific skills and detailed planning, while the facts are rather the opposite. Real structural behavior data sets. The complete data sets collected over long-terms are needed to fully understand real structural behavior and its interaction with environment. The SHM was applied to various types of structures, but the results of monitoring are frequently only partially disclosed or incomplete, thus the knowledge basis is rather deficient. Change in strain patterns caused by unusual behaviors. The patterns of degradation in performance and damage in monitoring results are often “masked” by environmental influences (temperature, wind, humidity, etc.) and human-made actions (live load fluctuations) and consequently, cannot be reliably identified in controlled laboratory conditions. More real data with unusual behaviors are needed in order to develop reliable detection algorithms. Characterization of SHM contribution to sustainability of built environment. SHM has promising potential to contribute to the sustainability of built environment since it provides with objective information concerning the real structural performance, which can be used as an input to optimize maintenance, extend structure’s life, increase safety, decrease life-cycle costs, reduce the use of construction material, minimize adverse impact on society that may occur in case of structural deficiency, and help reducing greenhouse gas emissions. Besides addressing above listed challenges, the Streicker Bridge will be used for full scale testing of new SHM methods, and newly developed monitoring systems.
|INSTALLATION PERIOD||TYPE OF SENSORS||NUMBER OF SENSORS|
|2009||DiTeSt / DiTemp , MuST||56|
Scientific contributions. Monitoring results will increase knowledge basis concerning the real structural behavior and help building reliable algorithms for damage and performance degradation detection based on objective data. In addition, future sensing technologies and methods will be installed and tested on the bridge. The influence of SHM to improvement of long-term bridge management and decrease of life-cycle costs will be evaluated and the SHM contribution to sustainability of built environment will be assessed. The results may have potential impact in several other fields of civil engineering such as numerical modeling, structural analysis, life-cycle performance, and materials science. Educational contributions. The SHM of Streicker Bridge will be of significant support to newly introduced graduate course CEE 539 on SHM – students will be involved in all phases of project including design of monitoring strategy, installation of the system, and data handling, interpretation and analysis. Beside the course on SHM, the instrumented bridge will be of great support to the other departmental courses such as newly introduced Theory of Structures, and existing courses on Mechanics of Solids, Structural Analysis, etc. Broader impact. The Bridge itself will be transformed in a laboratory which will serve not only for scientific and courses purposes, but will also be used for demonstration purposes to K-12, public, policy makers (e.g. students of Woodrow Wilson School as future policy makers), and decision makers from various administrative units (e.g. departments of transportation – DOT). Finally, an increased safety for the bridge users and improved management for the bridge owner are expected.