Three finite element models have been developed to analyse the cross-sectional forces in the joints of multi-beam box girder bridges. A major theme of this paper is to indicate the limits of the current design methods based on linear analyses. A model based on shell elements is used in non-linear analyses including two analysis phases. The analysis phases simulate the construction phases. For straight bridges current design methods based on orthotropic plate models give reasonable results compared to the results of the advanced model. For bridges with a skew or curved geometry plan orthotropic plate models give poor predictions for the forces and moments in the joints. Advanced modelling, as presented in this paper, is then to be preferred. C. M. Frissen, M. A. N. Hendriks, TNO Building and Construction Research, Delft, The Netherlands N. Kaptijn, A de Boer, H. Nosewicz Ministry of Public Works and Water Management, The Netherlands
The offshore oil industry is still a comparatively young sector of structural engineering. The first oilfield offshore structures were installed just over 50 years ago in 4m water depth in the Gulf of Mexico. In the last 50 years some 9000 shallow water platforms have been built and the industry is now developing in very deep water. This paper provides an overview of offshore structural engineering through reference to the principle forms of offshore structure and their key design and operational requirements and the floating and sub sea structures that are making it possible to develop oilfields in 2km water depths. Richard Snell, FREng, FICE BP Exploration
本文回顾了可靠性技术评估桥梁结构充足性的使用，并强调了这种分析的输出如何既可以为用户调查结构的调查，并指导用户。确定了解释可靠性指标价值的三种不同方法，并检查了使用每一种来优先修复和加强工作的可行性。提出了针对不同桥梁类型和故障模式的可靠性指数的平均可接受值（AAV），并表明可以通过比较可靠性指数直接识别优先级，有时需要对可靠性指数的重要性进行衡量，在其他情况下，优先事项仍然不明显，需要进一步调查。为了实现这一目标，探索了风险管理的原则，并表明在两个或多个结构具有相似的可靠性的情况下，考虑风险确实代表了一种可行的方法。罗伯特·J·拉克（Robert J.