Seismic Response of Long‐Span Triple‐Tower Suspension Bridge under Random Ground Motion

Abstract

Multitower suspension bridge is of different style compared to the traditional suspension bridge with two towers, and consequently the dissimilarity of static and dynamic behaviors is distinct. As a special case of multitower suspension bridge, two long-span triple-tower suspension bridges have been constructed in China and the seismic random response of triple-tower suspension bridges is studied in this paper. A nonlinear dynamic analysis finite element model is established in ABAQUS and the Python language is utilized to facilitate the preprocess and postprocess during the finite element analysis. The procedure for random response calculation of structures based on the pseudoexcitation method is presented, with the initial equilibrium state of structure considered, which may be ignored for long-span bridges during calculating of stochastic response. The stationary seismic random responses of triple-tower suspension bridge under uniform excitation in firm, medium, and soft soil conditions and under spatially varying excitation in soft soil are investigated. The distribution of RMS of random responses of displacements and internal forces of the stiffening girder and towers is presented and discussed in detail. Results show that spatially variable ground motions should be considered in the stochastic analysis of triple-tower suspension bridge.

Seismic Responses of an Isolated Long-span Bridge using Frequency Domain and Time Dependent Procedures

“…Differentiations in soil conditions induces significant variations in seismic responses of bridges with high piers and more flexible soil can cause the higher seismic responses [21]. Since the seismic responses are dependent on the dynamic characteristic of the bridge and the PSD of input excitations, the model of coherency and the apparent velocity, the spatially varying ground motions play important role in the bridge analyses [22]. In suspension bridges, the response values obtained for the site-response effect alone are larger than the response values obtained for the incoherence and wave passage effects, separately [23].…”

Parametric analysis of the dynamic characteristics of a long-span three-tower self-anchored suspension bridge with a composite girder

“…on the static deformation characteristics of a three-tower suspension bridge with two 2000 m main spans by trial design; Jia et al (2018aJia et al ( , 2018bJia et al ( , 2020 derived simplified formulas for determining the static behavior of a super long-span three-tower GSB and systematically examined the influences of factors such as the sag-to-span ratio, side-to-main-span ratio, middle tower stiffness, girder-height-to-span ratio, girder-width-to-span ratio, and tower-to-girder constraint condition on the static structural performance of the three-tower suspension bridge. In terms of the dynamic characteristics and performance, Wang et al (2010) investigated the influence of factors such as the stiffening girder stiffness, tower-to-girder constraint condition, and central buckle on the structural dynamic characteristics of three-tower GSBs using the Taizhou Yangtze River Bridge in China as a case example; Wang et al (2014) and Tao et al (2018) carried out parametric analysis of the dynamic characteristics to further study the influence of the key structural parameters of three-tower GSBs on the flutter and buffeting performances; Jiao et al (2017) also used the Taizhou Yangtze River Bridge as a case example to investigate the seismic responses of threetower GSBs under random ground motion. However, most studies on three-tower systems take GSBs as the research object, while there is relatively little engineering practice and relevant research on TSSBs.…”