載荷車両の動的効果を考慮した道路橋の地震応答特性

Abstract

The effect of vehicle loading on the seismic load of highway bridges isdiscussed. Urban expressways that are subjected to frequent traffic congestions areof primary concern. For this purpose, it is assumed that a bridge is loaded withheavy trucks at the moment of earthquake occurrence. The subject is dealt with asa dynamic interaction problem between bridge structures and vehicles. Bridge-vehicle systems are analyzed in terms of complex eigen-value problem and responsetime-history analysis. The vibration modes pertinent to the effect of vehicle loadingare identified. The result of earthquake response analysis is examined extensivelyby comparing the responses of bridge-vehicle systems and those of bridge-alone forvarious conditions of input earthquake motions and truck weight. From theseresults, the effect of vehicle loading on the seismic loads is made clear. On thisbasis, some coments are made on bridge desigh.