As a service to the bridge design profession, Bethlehem Steel has conducted hundreds of studies of steel plate girder bridges using its Preliminary Bridge Girder Optimization Program. The program is unique because it optimizes plate girder designs on the basis of least cost, not least weight. An evaluation of many study results leads to a number of guidelines which are offered in this paper. Wh...

The segmental prestressed concrete box girder of Koror-Babeldaob (KB) Bridge in Palau, which had the record span of 241 m (791 ft.), presents a striking paradigm of serviceability loss due to excessive multi-decade deflections. The data required for analysis have recently been released and are here exploited to show how the analysis and design could be improved. Erected segmentally in 1977, thi...

This paper presents a method for modeling and analysis of cablestayed bridges under the action of moving vehicles. Accurate and efficient finite elements are used for modeling the bridge structure. A beam element is adopted for modeling the girder and the pylons. Whereas, a two-node catenary cable element derived using exact analytical expressions for the elastic catenary, is adopted for modeli...

The nearly 21-year-old Jiujiang Bridge, which is suffering from uneven line shape, constant great downwarping of the main beam and cracking of the box girder, needs reinforcement and cable adjustment. It has undergone cable adjustment for twice with incomplete data. Therefore, the initial internal force state of the Jiujiang Bridge is identified as the key for the cable adjustment project. Base...

To improve the stability of the magnet-girder assemblies in the ESRF storage ring, vibration investigations have been carried out for in situ magnet-girder assemblies and a prototype. Characterisation tests were performed : operating response measurements, static stiffness measurements, modal testing. A finite element modelling (FEM) is being carried out for the prototype assembly. First result...

In order to study the relationship between bearing capacity of structure and damage degree, author proposed parameter analysis heat storage loss test concrete composite box girder. Taking five-span prestressed girder as an example, different degrees are simulated by reducing bending stiffness parts, modal strain energy method flexibility difference used diagnose structural damage. The results s...

In order to evaluate the mechanical condition and working performance of a rigid frame bridge after reconstruction extension, was analyzed by static load test. Static test is stress at each section main beam under action partial medium load. The results show that, load, check coefficient strain deflection measuring point box girder does not exceed standard limit value 1, relative residual or de...

In earlier work we developed inductive coupling for surface-mounted Lamb wave transducers operating at relatively low frequencies, such as 300 kHz. We now report on similar inductively-coupled transducers at higher (multiple MHz) frequencies. Our investigation was motivated by a particular application, to examine a box girder top flange, using transducers mounted along the flange edge. We emplo...

A new surveying system using a laser and a CCD camera with image processing has been developed to align magnets on a 5 m-long girder to an accuracy of 10 l.trn. A spacial filter with a pinhole and a collimator are used to make a parallel gaussian beam. In order to stabilize the laser axis, the heat capacity of the laser was made larger to reduce the influence of the fluctuation in the room temp...