Figure - available from: Bulletin of Earthquake Engineering
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Structural layout and key section dimension of the prototype CRFB (unit: cm): a main girder segment and bearing; b span arrangement and pre-stressed tendon distribution; c box girder dimension; d main pier dimension; and e transition pier dimension
Source publication
Continuous rigid-frame bridges (CRFBs) have been widely constructed in high seismicity areas in western China. To investigate the seismic response characteristics and whiplash effect mechanism of CRFBs under near-fault ground motions, a long-span CRFB with high piers is selected as a prototype bridge, and a nonlinear finite element model is develop...
Citations
... Sui et al. evaluated the seismic performance of the arch bridge and proposed the seismic reinforcement method with additional dampers [23]. The analysis at the structure level in civil engineering has been further developed [24][25][26][27][28], and the research results show that the mechanical performance of structures may not be fully reflected in the simple superposition of member ultimate states [29][30][31][32]. In recent years, studies on arch bridges have shown differentiated analysis results [33][34][35][36][37], which shows that the complex structural characteristics of arch bridges may affect the mechanical behavior of structures [38][39][40]. ...
In the present study, multiscale finite element (FE) models of half-through steel basket-handle arch bridges were established. The eigenvalue analyses were conducted to explore the dynamic characteristics of the arch bridges based on the FE models. In addition, a parametric analysis was carried out to investigate the impact of the inclination angle of the arch rib (0°, 4°, and 7°) on the longitudinal and transverse seismic performances of arch bridges. The results show that with the increase in inclination angle, the out-of-plane stiffness of half-through steel basket-handle arch bridges increases, resulting in the natural period of the structure becoming shorter from 3.09 s to 2.93 s. Adjusting the inclination angle appropriately has a beneficial impact on the overall seismic performance of the structures, affecting both displacement and internal forces, in which the most significant improvements include a 42.8% decrease in displacement and a 62.6% reduction in internal forces. Adjusting the inclination angle can cause the arch springing and transverse brace to undergo larger plastic deformation. It is advisable to judiciously enlarge the sectional dimensions and enhance the material strength of both the arch springing and the transverse bracing in seismic designs.
... Located in the intersection area of the Circum-Pacific and Euro-Asian seismic belts, China experiences widely distributed seismic belts and frequent seismic activities [1]. Numerous bridges, both as-built and in-construction, are highly prone to earthquake-related damage [2]. The number of bridges is increasing, the span is increasing, and the operating environment is getting worse. ...
... The Hertz-Damp model is employed as the impact model to simulate the longitudinal pounding effects between the main GEs and transition pier's top. The mechanical parameters of the nonlinear elements and pounding model are determined by Li and Xu (2023c). The pile-soil-structure interaction is not considered, so it is assumed that the bottom of all piers is consolidated on the ground. ...
... The average values of peak seismic responses under all ground motion sets are the main focus of this study. The seismic response under each ground motion set having different characteristic has been compared by Li and Xu (2023c). Figure 8 depicts the transverse deformation of the main girder obtained from all the analysis models. It should be noted that the horizontal translational displacement of the main girder is equal to the displacement at the top of the main pier due to the stiff connection between the girder and pier. ...
In recent years, increasing attention has focused on seismic performance of long-span continuous rigid-frame bridges (CRFBs) under near-fault earthquake excitations. To investigate the characteristics of near-fault seismic response of CRFBs and improve their seismic performance, this study develops a hybrid seismic control system (HSCS) and establishes 22 uncontrolled models and 22 controlled models varying in span and pier height. Transverse whiplash and spatial torsion effects of the uncontrolled and controlled models are analyzed comparatively. Control performance of HSCS is evaluated and parametric study is conducted to investigate the effect of friction, damping, and ground motion on the response of HSCS-controlled CRFB. The results indicate that, in practical applications, the transverse whiplash and spatial torsion effects of CRFBs should be considered, particularly in multi-span CRFBs with unequal-height piers. The span and pier height have significant impact on these two effects and the corresponding girder end displacement, girder base, and pier bottom moment. Controlled bridges exhibit lower levels of these responses compared to uncontrolled bridges, and the displacement and bending moment are markedly reduced at a high control ratio of 0.4. Parametric analysis results show that the HSCS provides excellent seismic control performance for near-fault CRFBs when the optimum parameter values are used. This study may provide a useful reference for the seismic design and performance improvement of near-fault CRFBs.
... Nonlinear Li and Xu (2023b). The pile-soil-structure interaction is not considered, so it is assumed that the bottom of all piers is consolidated on the ground. ...
In recent years, increasing attention has focused on seismic performance of long-span continuous rigid-frame bridges (CRFBs) under near-fault earthquake excitations. To investigate the characteristics of near-fault seismic response of CRFBs and evaluate the effectiveness of a hybrid seismic control system (HSCS), this study establishes 22 uncontrolled models and 22 controlled models varying in span and pier height. A comprehensive seismic evaluation method based on a fuzzy logic control (FLC) algorithm is proposed. Transverse whiplash and spatial torsion effects of the uncontrolled and controlled models are analyzed comparatively. Control performance of HSCS is evaluated and parametric study is conducted to investigate the effect of friction, damping, and ground motion on seismic response of HSCS-controlled CRFB. The results indicate that, in practical applications, the transverse whiplash and spatial torsion effects of CRFBs should be considered, particularly in multi-span CRFBs with unequal-height piers. The span and pier height have significant impact on these two effects and the corresponding girder end displacement, girder base, and pier bottom moment. Controlled bridges exhibit lower levels of these responses compared to uncontrolled bridges, and the displacement and bending moment are markedly reduced at a high control ratio of 0.4. Parametric analysis results show that the HSCS provides excellent seismic control performance for near-fault CRFBs when the optimum parameter values are used. This study may provide a useful reference for the seismic design and performance improvement of near-fault CRFBs.
