Abstract

Reinforced concrete bridges constitute the major part of existing bridges. The purpose of this paper is to present a serviceability evaluation methodology for RC bridges under probabilistic conditions. It will be based on analytical calculations with no need to complex modeling or advanced software. For this purpose, a realistic traffic model is simulated based on existing weigh-in-motion WIM data from some European sites. The probabilistic distributions of the time-dependent load effects, moment and deflection, are then deduced after hundreds of simulations. The degradation effects are introduced in the analysis by considering the concrete creep and shrinkage. A simplified model to introduce creep effect under variable traffic load is also proposed. The time dependent reliability indices are then calculated for a set of 21 simply supported RC T-beam bridges with varying parameters such as span lengths, number of girders, girder spacing and number of design lanes. The first order reliability method FORM, is used in the reliability calculation in order to evaluate the structural performance under the considered failure scenario.

摘要

钢筋混凝土桥梁是现有桥梁的主要组成部分。本文的目的是提出一种概率条件下 RC 桥梁的适用性评估方法。它将基于分析计算，无需复杂的建模或高级软件。为此，基于来自一些欧洲站点的现有动态称重 WIM 数据模拟了一个真实的交通模型。然后在数百次模拟之后推导出与时间相关的载荷效应、力矩和挠度的概率分布。通过考虑混凝土的徐变和收缩，在分析中引入了退化效应。还提出了在可变交通负载下引入蠕变效应的简化模型。然后计算一组 21 座简支 RC T 型梁桥的时间相关可靠性指数，这些桥具有不同的参数，例如跨度长度、梁数、梁间距和设计车道数。一阶可靠性方法 FORM 用于可靠性计算，以便在考虑的故障情况下评估结构性能。