MODAL ANALYSYS OF VIADUCT ROAD VIBRATIONS

Abstract

Viaduct roads have wide applications in big cities carrying high traffic load in order to decrease the traffic density and to conduct the subways to highways. Viaduct roads are constructed by steel structures instead of concrete ones on areas of earthquake risks. The low weight of steel structures causes problems such as vibration and noise. There is an increasing demand especially in populated areas to suppress vibration and noise in highway roads for reducing noise related environmental pollution. In this research, it is demonstrated that modal separation and modal actuation of structural modes of a flat and curve roads using cluster filtering and cluster actuation depend on the existing modal symmetry axes. Every eigenfunction of a two-dimensional structure can be expressed in a form of the "(m, n) modes", m and n being modal indices. Simulation results obtained using FEM model of flat road show only the certain mode groups such as odd / odd, even / odd, odd / even, and even / even ones. When studying a curved viaduct road, it is possible to classify mode groups as odd / odd or even and even / even or odd.