Dynamic Response Of Special-shaped Continuous Box Girder Bridge Due To Moving Vehicles

When vehicle running through the bridge, they consists of a complicated vehicle-bridge interaction system. Due to the roughness of the bridge deck, so the vehicleproduced a excitation on the bridge in addition to static. The bridge was inspired alsoproduced the corresponding vibration, which in turn has an incentive effect on thevehicle. So that the vehicle-bridge interaction system may becomes more and morecomplex. In bridge structural design process we must take the bridge response under amoving vehicle and the problem is becoming more and more important..This paper uses a actual bridge project as an example. We use the Finite ElementSoftware to establish the bridge structure model of special-shaped continuous boxgirder bridges. Then after Finite Element Solution we obtain the free vibrationfrequency of bridge structure, the modal mass, modal stiffness and the vibration shapeof the nodes. This paper also design simulation of straight beam with the same section,curved beam is calculated by the finite element software ANSYS, verifies thereliability of using the finite element software. Using the Lagrange equation to derivethe two-axis plane vehicle model with four degrees of freedom and seven degrees offreedom of two-axis is also be derived. The bridge and the vehicle is considered astwo independent systems. Establish the motion equation, respectively. Thecombination of the two independent systems is the displacement compatibilitycondition of the contact point of the vehicle tire and bridge deck. Then the responseanalysis system of vehicle-bridge dynamic has been established. We use FORTRANLanguage to edit vehicle-bridge interaction calculation program. We have done someanalysis under different roughness, vehicle velocity, vehicle routing about the noderesponse in a same section. the surface roughness, vehicle speed, the dynamicresponse of special-shaped block intersection vehicle running route. And we haveanalysis the dynamic response of the intersection point under a certain roughness,vehicle speed, and vehicle routing. The results show that when the vehicle speed increases the bridge impactcoefficient has no obvious change. When the roughness of the bridge deck is greater,bridge impact coefficient increased, but the relationship between them is not linear.Influence of the vehicle running route on the bridge impact coefficient is not large...