Fatigue Damage Estimation in Existing Railway Steel Bridges by Detailed Loading History Analysis

Fatigue life estimation of metal historical bridges is a key issue for managing cost-effective decisions regarding rehabilitation or replacement of existing infrastructure. Because of increasing service loads and speeds, this type of assessment method is becoming relevant. Hence there is a need to estimate how long these structures could remain in service. In this paper a method to estimate fatigue damage in existing steel railway bridges by detailed loading history analysis is presented. The procedure is based on the assumption that failure probability is a function of the number of predicted future trains and the probability of failure is related to the probability of reaching the critical crack length

fatigue behaviour of steel bridge joints strenghtened with frp laminates

One of the most relevant concerns about steel and metal bridges stands on the repair and rehabilitation of existing structures. In fact, the remaining service life of steel bridges is limited by fatigue damage and in order to ensure the safety of these bridges it is often necessary to inspect the structure in order to discover the presence of fatigue cracks. New reinforcement techniques are needed, in order to prevent fatigue cracking and to increase bridge safety at the same time. According to the contemporary knowledge on the matter, two alternatives of rehabilitation are given: the traditional interventions and the use of carbon fibre composites. In this paper, in order to explain the appropriate use of these techniques, the most common knowledge on the matter are presented and explained, focusing in particular on the real scale testing results coming from the last decades research applications related to steel bridge engineering. This study should in this way be useful for future research applications and for bridge engineering real case rehabilitations

Structural Analysis of the Cantilever Construction Process in Cable-Stayed Bridges

This work deals with the analysis of cable-stayed bridges at different erection stages during construction, assuming the full or the partial cantilever method and performing multiple finite element computational procedure. The forward process and the backward process analysis are investigated and compared: the former is performed by following the sequence of erection stages in bridge construction and the latter is carried out in the reverse direction of erection procedures. The required pretension in cable-stays and the corresponding structural configurations of the bridge at different erection stages have been examined and compared in details, also by comparing either the linear computation procedure or the nonlinear computation procedure. Numerical, analytical and construction process results are presented, compared and commented upon

Life cycle assessment of existing steel bridges considering corrosion and fatigue coupled problems

Corrosion and fatigue are important issues which affect the structural performance of steel bridges. This is particularly important for bridges and viaduct, for their key role in infrastructural nets. As the management of bridges net requires the prediction of the remaining life for all partially deteriorated structures, the development of assessment models for time-varying changes in structural performance due to the coupled problem of corrosion and fatigue is relevant and need to be investigated. In this paper, the accumulated load cycles causing cracking or even failure is analyzed together with different scenarios of corrosion propagation. The analysis is performed for the fatigue limit state function of shear in a detailed riveted connection. Predic- tion of the remaining fatigue life is illustrated on a typical example of existing bridge girders. Variations in the remaining life are evaluated as a function of time, covering the whole life-time of the bridge