Modal Analysis of a Steel Truss Girder Cable-Stayed Bridge with Single Tower and Single Cable Plane

Abstract

The dynamic characteristics of bridge structures are important in wind stability analysis, seismic design, fatigue assessment, health inspection, and maintenance of bridge structures; however, the mechanical and dynamic properties of different bridge types are different. A long-span cable-stayed bridge has the advantages of large flexibility, long natural vibration period, low natural frequency, dense spectrum, and denser modal than those of general structures. In this paper, the dynamic characteristics of a cable-stayed bridge with single pylon and single cable plane in the maximum cantilever stage and the complete bridge are analyzed. The single-tower cable-stayed bridge has some unique characteristics, such as lower cost, and a more beautiful appearance, but its torsional rigidity is lower, which increases the risk of wind damage and earthquake damage. Therefore, a finite element analysis of this bridge in the maximum cantilever state is carried out, and the influences of the main components’ rigidity, the inclination angles of the stayed cables, the supporting conditions, and the locations of the auxiliary piers are analyzed for the sustainability of this type of cable-stayed bridge. The analysis results show that a cable-stayed bridge with single pylon and single cable plane has more flexibility, and that the lateral rigidity and torsional rigidity are smaller. Structure rigidity, dip angles of the stayed cables, and positions of the auxiliary piers all have significant influences on the dynamic characteristics of cable-stayed bridges.

Influence Analysis of Natural Vibration Characteristics of Steel Box Girder With Single Cable Face and Large Cantilever

“…From the first 10 natural vibration modes of the model, it can be seen, that the vibration modes of the studied structure are dominated by vertical bending vibrations of the deck, which corresponds to the structural characteristics of a rigid deck and flexible stay cables. The vibration behaviour of the studied structure is more similar to that of a continuous girder (rigid structure) and other girder bridges, unlike general cable-stayed bridges where the torsion of towers and cables is the main vibration pattern [18].…”

Fatigue experimental study on full-scale large sectional model of orthotropic steel deck of urban rail bridge

“…Therefore, the fatigue load reduction factor multiplied by the designed train axle load is selected as the value of the axle loads of the fatigue load model of the urban rail transit bridge. The fatigue load reduction factor is finally determined to be 0.8, 3,24,25 in accordance with the linear fatigue cumulative damage theory and the corresponding train design axle load.…”

“…17,18 Moreover, the fatigue performance of rib-to-floorbeam welded connection in orthotropic steel decks reinforced by using ultra-high-performance concrete (UHPC) overlay is also studied. 19 Compared with rail transportation, highway transportation has diversified vehicle types, [20][21][22][23][24][25][26][27] but the load effects are relatively small. Railway transportation and urban rail transits have certain similarities, that is the load type is single with strong regularity, but the load effect is larger.…”

Fatigue Life Evaluation of Orthotropic Steel Deck of Steel Bridges Using Experimental and Numerical Methods

“…Two methods of calculating the extension step are provided in Franc3D software. One is to specify the extension step for the node located at the median value of the stress intensity factor; the extension step for all other nodes is obtained by appropriate scaling, and the other is to specify the number of cycles of the load and solve directly for the extension step for each node according to the Paris law [32][33][34]. In this section, the former method was used to calculate the expansion step for the nodes on the leading edge of the crack, specifying the expansion step at the median stress intensity factor to be less than or equal to fifteen percent of the characteristic size of the crack for a total of 37 expansion steps.…”