ABSTRACT
The high safety requirements for railway infrastructures are a basic demand that the railway user places on the railway operator. Noise barriers that are erected along high-speed railway lines are loaded by aerodynamic pressure and suction waves due to the passing trains. Noise barriers are an integral part of railway infrastructures, and their level of safety must be maintained throughout their entire lifetime. This concept paper discusses deterministic and probabilistic-based approaches for condition assessment and prognosis of remaining service life of railway noise barriers, embedded in a safety concept that takes damage consequence classes into account. These approaches are combined into a holistic assessment concept, in other words a progressive four-stage model in which the information content increases with each model stage and thus successively increases the accuracy of the determined structural conditions at the time of observation and the forecast for the remaining service life of the structure. The analytical methods used in the first stage of the developed holistic framework are based on common static calculations used in the engineering practice and, together with expert knowledge and large-scale fatigue test results of noise barrier constructions, form the basis for the subsequent stages. Linking routines that combine the condition assessments from the common executed visual inspections and additional information from permanent monitoring systems applied to failure-critical elements with the analytical methods of the first stage are implemented in the second stage of the holistic framework. With application of numerical finite element methods in the third stage and finally the probabilistic approaches in stage four, the highest degree of determination accuracy of the noise barrier condition at the time of observation and prediction accuracy of the remaining lifetime shall be achieved. Depending on how far the degradation of the considered noise barrier has already progressed, the corresponding stage of the holistic assessment concept is activated, which enable infrastructure managers to plan their future investments regarding maintenance, retrofit or rebuilt of noise barriers more economically. The aim is to integrate the project results into a supranational framework, which is established through orientation towards Europe-wide preliminary projects.
