The effect of imperfect boundary conditions on the collapse behavior of anisotropic shells

The objective of this paper is to provide highlights of the most important references related to the development of current guide specifications for the design of straight and curved box-girder bridges. Subjects discussed in this review include (1) different box-girder bridge configurations; (2) construction issues; (3) deck design; (4) load distribution; (5) deflection and camber; (6) cross-bracing requirements; (7) end diaphragms; (8) thermal effects; (9) vibration characteristics; (10) impact factors; (11) seismic response; (12) ultimate load-carrying capacity; (13) buckling of individual components forming the box cross section; (14) fatigue; and (15) curvature limitations provided by the codes for treating a curved bridge as a straight one. The literature survey presented herein encompasses (1) the construction phase; (2) load distribution; (3) dynamic response; and (4) ultimate load response of box-girder bridges.

State-of-the-art in design of curved box-girder bridges

A consideration on intermediate diaphragm spacing in steel box girder bridges with a doubly symmetric section

(1) Doctoral Student, School of Mechanical and Vehicular Engineering, Beijing Institute of Technology (BIT), China, beri@bit.edu.cn (2) Post Doctoral Student, School of Mechanical and Vehicular Engineering, Beijing Institute of Technology (BIT), China, longkai@bit.edu.cn (3) Prof. & Dean, School of Mechanical and Vehicular Engineering, Beijing Institute of Technology (BIT), China, zxzuo@bit.edu.cn

Design Optimization of EOT Crane Bridge

Intermediate diaphragms are used in box girders not only to prevent premature distortion under eccentric loading conditions but also to improve the distribution of live loads. This paper reports an investigation into the effect of intermediate diaphragms on the load - carrying capacity of a Steel – Concrete Composite Box (SCCB) girder bridge with open steel box section. In the current study, a three - dimensional finite element (FE) model of the SCCB girder is developed and analyzed using ABAQUS software. The nonlinear inelastic analysis is invoked in order to accurately capture the actual behavior of the girder. The numerical model is verified with experimental results to ensure the accuracy of the FE modeling method. A parametric analysis is implemented to study the effect of intermediate diaphragms on the load – carrying capacity of an SCCB girder with a 30–60 m span length. Based on parametric studies, the number of intermediate diaphragms (N) is recommended for practical design of the girder, which satisfies the requirement stated in the provisions of the AASHTO LRFD standard.

Effect of intermediate diaphragms on the load – carrying capacity of steel – concrete composite box girder bridges

A parametric study is carried out to determine the optimum design of load-bearing box girder diaphragms which are supported on a single bearing positioned at the diaphragm centre line. The parameters varied include the depth/breadth ratio, the depth/thickness ratio, the size and location of stiffeners and the eccentricity of loading. The criterion used for comparison purposes is the collapse load for each configuration, this being determined using a finite element package. Finally, the effects on the collapse load of the different configurations are discussed and recommendations made.

Optimum design of load-bearing box girder diaphragms having a central support

A parametric study is carried out to determine the optimum design of load bearing box girder diaphragms in which the supports are positioned at the flange/web junctions of the box girder. The parameters varied include the depth/breadth ratio, the depth/thickness ratio, the size and location of stiffeners and the eccentricity of loading. The criterion used for comparison purposes is the collapse load for each configuration, this being determined using a finite element package. Finally, the effects on the collapse load of the different configurations are discussed and recommendations made.

Optimum design of load-bearing box girder diaphragms having supports at the flange/web junctions

A method, using a new surveying technique, is used for the measurement of the geometric initial imperfections in box girder diaphragms. The method, accurate to ±0·1 mm , may be used on diaphragms contained in a box girder where contact with the surface of the diaphragm is difficult or impossible or inadvisable due to the presence of strain gauges.

Measurement of the geometric initial imperfections in diaphragms

A parametric study is carried out to determine the optimum design of load-bearing box girder diaphragms in which the supports are positioned at a distance from the flange/web junctions of the box girder. The parameters varied include the depth/breadth ratio, the depth/thickness ratio, the size and location of the stiffeners and the eccentricity of loading. The criterion used for comparison purposes is the collapse load for each configuration, this being determined using a finite element package. Finally, the effects on the collapse load of the different configurations are discussed and recommendations made.

G. Hallak

Papers

Optimum design of load-bearing box girder diaphragms having a central support

Optimum design of load-bearing box girder diaphragms having supports at the flange/web junctions

Measurement of the geometric initial imperfections in diaphragms

Optimum design of load-bearing box girder diaphragms having supports at a distance from the flange/web junctions