Dynamic Analysis of Hyperestatic Structures under High Speed Train Loads

The construction of new high speed railway infrastructure in many European countries is actually a great civil engineering effort. One of the main design issues is related to the fact that trains at speeds above 220 km/h may induce resonance effects in structures as bridges, subway frames, etc. In consequence, the design of such structures requires dynamic calculations. Several methods are available for the dynamic calculations of structures under high speed train loads. The simplest ones are based on sums of harmonic terms, providing upper bounds for the dynamic response, and with application limited to isostatic bridges. Alternatively, for statically indeterminate structures some models based on the direct time integration of the equations of motion are available. These methodologies suitable for hyperestatic structures, performed on full or reduced models, are discussed in this paper. Additionally, some recent results for high speed traffic loads on bridges are presented. The object of these studies is diverse: simplified torsion analysis, a proposal of a simplified method for dynamic analysis of portal frames, and several practical results obtained for concrete bridges, composite steel-concrete bridges and pre-casted concrete bridges.