The German federal highway system is facing major challenges: Existing structures are ageing continuously while the budget for repair and maintenance measures will remain limited. Additionally, there are increasing traffic loads, effects of climate change and new quality requirements in terms of sustainability.
Currently, maintenance management is damage-based and reactive in the first place. In the course of regular structural inspections, damage is only discovered when it is obvious. However, if insufficient bearing capacity due to increasing loads, other structural deficits or insufficient financial means are to be taken into account, detailed knowledge of the actual condition and reliable prognoses may become necessary.
New innovative approaches
New and innovative approaches must be integrated into maintenance management and further developed in order to maintain a reliable road system. This applies in particular for bridge structures.
The objective of the topic “Smart bridges” is therefore to develop an adaptive system to provide relevant information and holistic evaluation in real time.
In addition to structural inspections, a suitable tool is implementation of suitable sensor systems combined with analysis and assessment procedures. Using the support of sensor systems, information about expected damage and changed conditions that is currently not available can be provided.
The basis for reliability-oriented and anticipatory maintenance management can be laid by combining prognosis models and currently available information from databases.
The systems to be designed should work adaptively. This means that information provided by various sensors is combined and assessed holistically by means of a reliability-based expert system.
Ideally, the system of smart bridges is available from the time a bridge is first used, for example before damage or deterioration is discovered.
Sensor system and assessment methods
It is therefore necessary not only to collect measurement data but also assess them and make a prognosis in real time. A corresponding software expert system should alert users, administrations and owners automatically if necessary. In the future, this may result in self-organized reactions (adaptive structure).
Within the complex structure of intelligent bridges, a large number of components and aspects influencing each other must be taken into account. Most aspects can be assigned to the following three component groups: Intelligent sensor system, intelligent assessment procedures and intelligent maintenance management.
The measurement values, collected by means of intelligent, wireless and energy-efficient sensors and sensor networks feed assessment models that on the other hand have considerable influence on the requirements of the system in terms of the choice of measurement values and sampling rates. These two component groups are included in continuously updated maintenance management.
The main objective is to supplement the current deterministic approach, in particular by means of reliability-oriented methods.
The individual aspects are developed in the scope of internal and external projects that are planned for the period between 2010 and 2015; they will then be combined in the realization of an intelligent prototype.