Bridge Structures - Volume 10, issue 4

Authors: Mahmoud, Khaled M.

Article Type: Other

DOI: 10.3233/BRS-150085

Citation: Bridge Structures, vol. 10, no. 4, pp. 115-115, 2014

Authors: Monzon, Eric V. | Itani, Ahmad M. | Pekcan, Gokhan

Article Type: Research Article

Abstract: Integral abutment bridges have certain advantages over conventional seat-type abutment bridges due to increased redundancy, higher damping, smaller displacements, and, thus, the elimination of unseating potential. However, there is a lack of information on their seismic modeling, system response, and seismic design. This paper presents the recommended guidelines for the seismic design of steel bridges with integral abutments. These guidelines are based on extensive analytical investigations as well as available experimental research. Contrary to the common assumption in analysis and design, nonlinear finite element analyses showed that the typical girder-to-abutment connection is not rigid and can influence the overall seismic …response of the bridge. A procedure for calculating the minimum required embedment length of the girder into abutment stem to achieve a rigid connection is proposed. A procedure to evaluate the steel pile ultimate lateral displacement capacity is also proposed. The use of the system-level damping due to yielding and inelastic response of the various components including the soil behind the abutments and around the piles is discussed. Show more

Keywords: Integral abutment bridges, seismic design, steel piles, seismic behavior

DOI: 10.3233/BRS-150080

Citation: Bridge Structures, vol. 10, no. 4, pp. 117-128, 2014

Authors: Al-Rousan, Rajai | Haddad, Rami H. | Al Hijaj, Mutaz A.

Article Type: Research Article

Abstract: This paper aims to find the optimum cable spacing and the optimum FRP deck stiffness in terms of vertical deformation. To achieve the objective of this study eighteen models are developed using ABAQUS; three different deck stiffness and six different cable spacing. Firstly, a non linear static finite-element analysis is performed on the models; then pre-tensioning forces are applied to cables, after that the shape modes for each model are presented. Secondly, a nonlinear dynamic analysis is performed on the models, the results obtained from the finite-element analysis are used in the optimization. The results show that for certain cable …spacing the deflection decreased, and the cable stress increased as the deck stiffness increased. Furthermore, for certain deck stiffness, the cable stresses and the maximum deck deflection increased as the spacing between cables increased. Secondary, a relationship is performed to find the optimum cable spacing for each deck stiffness and optimum deck stiffness for each cable spacing. Finally, new twelve models are developed in order to study the effect of deck types (FRP, Concrete and steel) on the static and dynamic behavior. The results show that the using FRP deck instead of the concrete deck will lead to vertical deformation and cable stress less than the allowable proposed values by the design code because of the light weight of the FRP materials. Show more

Keywords: Optimization, cable-stayed, bridges, cable spacing, deck stiffness, vertical deformation

DOI: 10.3233/BRS-150082

Citation: Bridge Structures, vol. 10, no. 4, pp. 129-143, 2014

Authors: Kataria, Nitin P. | Jangid, R.S.

Article Type: Research Article

Abstract: Present paper investigates the application of Magnetorheological (MR) damper for a seismic control of the horizontally curved bridge isolated with different passive devices. The main aim of the study is to investigate the effectiveness of hybrid system for the seismic control of curved bridge with variation of important parameters. The selected bridge is a three span continuous concrete box girder supported on pier and rigid abutment. The bridge deck is model as a single spine beam, which is made with number of small straight two node beam elements and supporting pier model as linear lumped mass system. The MR dampers …are located between the deck and abutments or piers in chord and radial direction. The bridge is excited with four different ground motions having different ground motion characteristics with all three-ground motion components (horizontal as well as vertical). The analysis results confirm use of MR damper with different isolator effective in controlling the response of the curved bridge and MR damper also effective in controlling the bearing displacement. The combination of MR and Lead rubber bearing (LRB) can provide an effective way for overall seismic control of curved bridge structure. Show more

Keywords: Seismic isolation, MR, ERB, LRB, FPS, curved bridge, seismic analysis

DOI: 10.3233/BRS-150083

Citation: Bridge Structures, vol. 10, no. 4, pp. 145-160, 2014

Article Type: Other

Citation: Bridge Structures, vol. 10, no. 4, pp. 161-161, 2014

Article Type: Other

Citation: Bridge Structures, vol. 10, no. 4, pp. 163-163, 2014