DYNAMIC ANALYSIS OF A COUPLED HIGH-SPEED TRAIN AND BRIDGE SYSTEM SUBJECTED TO SEA WAVE HYDRODYNAMIC LOAD

Abstract

IN THIS STUDY, THE DYNAMIC BEHAVIOR OF THE 3D TRAIN–BRIDGE SYSTEM SUBJECTED TO DIFFERENT HYDRODYNAMIC LOADS (TBW MODEL) IS ESTABLISHED. BY TAKING A CONTINUOUS BRIDGE (32 + 48 + 32) M WITH BOX GIRDERS AS A CASE STUDY, THE DYNAMIC RESPONSES OF THE BRIDGE WHICH IS UNDER TRAIN PASSING AND SUBJECTED TO SEVERAL SEA HYDRODYNAMIC LOADS ARE ANALYZED. THE SUBSTRUCTURE OF THE VIADUCT INCLUDES FOUR CONCRETE SOLID PIERS WITH RECTANGULAR SECTIONS AND PIERS ARE FIXED AT SEABED. PIERS AND DECKS ARE DESIGNED AND ANALYZED BASED ON DYNAMIC FINITE ELEMENTS METHODS, AND HYDRODYNAMIC FORCES ARE APPLIED ON PIERS ACCORDING TO MORRISON'S THEORY. ALSO, CAR BODY IS MODELED BY A 27-DOFS DYNAMIC SYSTEM. MODEL VALIDATION HAS BEEN PERFORMED WITH OTHER RESEARCH BY CONSIDERING VESSEL COLLISION LOAD. IN CONTINUATION, THE DYNAMIC RESPONSES OF THE BRIDGE AND THE RUNNING SAFETY INDICES OF THE TRAIN ON THE BRIDGE UNDER SEVERAL TYPES OF SEA WAVE STATES AND SEVERAL TRAIN SPEEDS ARE ANALYZED. CONSEQUENTLY AN ASSESSMENT PROCEDURE IS PROPOSED FOR THE RUNNING SAFETY OF HIGH-SPEED TRAINS ON BRIDGES SUBJECTED TO WAVE LOADS, AND RELATED THRESHOLD CURVES FOR TRAIN SPEED VERSUS SEA STATES ARE DEFINED. RESULTS OF TBW'S SENSITIVE ANALYZES SHOWN THE IMPORTANCE OF SEA-STATES CONDITIONS FOR TRAIN SAFE AND COMFORTABLE RUNNING. THESE OUTPUTS INDICATES THAT IN STORMY CONDITIONS (WAVE HEIGHT ≥ 8.5 M), THE SPEED OF THE TRAIN CROSSING THE BRIDGES SHOULD BE REDUCED AND IT IS POSSIBLE FOR THE TRAIN TO PASS AT LOW SPEEDS (UNDER 200 KM/H) IN STORMY CONDITIONS.