Analytical method for overturning risk assessment of curved girder bridges with single-column piers under heavy-duty vehicles

Failure Analysis for Overall Overturning of Concrete Single-Column Pier Bridges Induced by Temperature and Overloaded Vehicles

“…Three six-axle trucks were arranged in dense rows for loading vehicles The weight distribution ratios for the first six axles were 0.04, 0.19, 0.17, 0.21, 0.19, and 0.21. The total length of the vehicle was 15 m with axle spacings of 3.4 m, 0.9 m, 4.6 m, 1.6 m, and 1.6 m. Vehicle locations were determined by the most unfavorable influence sur face of the total overturning effect of the bridge [20], which is shown in Figure 3. The distance between the front and rear vehicles was set at 5 m, with the vehicle positioned 0.5 m from the curb.…”

“…Field investigations have revealed four common characteristics of bridges involved in overturning incidents [16][17][18]: (1) continuous girder bridges, generally with a single bearing at each mid-pier; (2) superstructures made of integral box-section girders; (3) straight girders or horizontally curved girders with a large curvature radius; and (4) overloaded vehicles moving or staying on the same deck side. The anti-overturning theory of the single-column pier bridges has evolved from rigid body rotation theory to deformed body and rigid body rotation superposition theory [9,19,20]. Xiong [21] established a detailed 3D bridge model including the superstructure, bearings, and piers to accurately describe the structural behavior under different mechanical conditions before the final collapse, and further explored the effect of different single-column pier bridge arrangements on overturning performance.…”

“…FE models that consider geometric nonlinearity, material nonlinearity, and dynamic effects are complex and computationally intensive [2,20]. Therefore, researchers adopt the support reaction method (SRM) or the factor of stability against overturning (FSO) [23] to address the overturning issues in practice.…”

“…Therefore, researchers adopt the support reaction method (SRM) or the factor of stability against overturning (FSO) [23] to address the overturning issues in practice. Some studies have proposed that the overturning of single-column pier bridges can be assessed based on the presence or absence of a disengaged bearing, indicating whether there is a negative support reaction [5,20]. While preventing the disengagement of all bearings in the limit state may avoid bridge overturning incidents, this approach does not provide a quantitative measure of the bridge's anti-overturning ability under overloaded vehicles.…”

“…The updated FSO method takes the line of the outermost bearing of each support section as the overturning axis (fold overturning axis), which has been integrated into the MTPRC2018 code [ 26 ]. Zhou [ 3 ] and Liu [ 20 ] highlighted that while the updated FSO method appears reasonable, it still presents several limitations. The method solely focuses on the role of torsion-resisting bearings and ignores the contribution of non-torsion-resisting bearings in anti-overturning during girder rotation.…”