INFLUENCE OF CHANGE OF VEHICLE LOADS ON FATIGUE RELIABILITY OF STEEL HIGHWAY BRIDGES

车辆荷载变化对公路钢桥疲劳可靠性的影响

• 批准号: 07650546
• 负责人: SHIRAKI Wataru
• 金额: $ 1.34万
• 依托单位: TOTTORI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650546/
• 关键词: highway bridges; fatigue reliability; large size truck; reinforcement and repair; earthquake reliability; 設計自動車活荷重; 亀裂進展則

In the new version of Japanese Highway Bridge Specifications revised in February, 1994, the design vehicle load is changed from 20 tf to 25 tf according to revision of the standard of the traffic vehicles. The change of design vehicle load is considered to be concerned with the reduction of fatigue reliability of existing highway bridges designed by the old version of the specifications. In this study, first, the influence is estimated by the fatigue reliability analysis of typical types of steel girder bridges. The analysis is performed for the vertical stiffeners connecting the central transverse girder to the web of the main girders by the use of a probabilistic fracture mechanics model and Monte-Carlo simulation technique. Second, a planning method of repair and reinforcement for highaway bridges is investigated. Furthemore, the reliability evaluation of rigid-frame steel pires of highway bridges subjected to earthquake load is done. The main results obtained in this study are as follows :(1) The change of traffic vehicle design load give a large influence on the fatigue reliability of bridges designed by the new version of the specification as well as the old one. The investigations for maintenance such as reinforcement and repair are required.(2) A optimization method which maximize the expected total cost benefit is introduced. The optimal method is introduced to determine the total number of repair, type of repair, and the time required for repair.(3) The studies on the fatigue reliability analyzes are performed for concret bridges, however, the results mentioned specially are not obtained.(4) The reliability levels for steel pires of existing highway bridges designed by the allowable stress design method (ASDM) are evaluated, and then the influence of load effect due to earthquake on reliability of pier structures is examined in detail. Some shortcomings of the ASDM are pointed out.

1994年2月修订的新版《日本公路桥规范》中，根据交通车辆标准的修订，将设计车辆荷载由20Tf改为25Tf。设计车辆荷载的变化被认为与旧版规范设计的既有公路桥梁疲劳可靠度的降低有关。本文首先通过对典型钢梁桥的疲劳可靠度分析，对其影响进行了评估。采用概率断裂力学模型和蒙特卡罗模拟技术，对连接中央横梁和主梁腹板的竖向加劲肋进行了分析。其次，研究了Highaway桥梁维修加固的规划方法。在此基础上，对公路桥梁刚构钢桥墩在地震作用下的可靠性进行了评估。主要研究结果如下：(1)交通车辆设计荷载的变化对新旧规范设计桥梁的疲劳可靠度有较大影响。提出了一种最大化期望总成本效益的优化方法。对混凝土桥梁进行了疲劳可靠性分析，但没有得到特别提到的结果。(4)评估了按许用应力设计法(ASDM)设计的既有公路桥梁钢管的可靠度水平，并详细分析了地震荷载效应对桥墩结构可靠度的影响。指出了ASDM的一些不足之处。

项目成果

白木渡・山本宏・松原孝介: "鋼製ラーメン橋脚の耐震信頼性評価" 構造工学論文集. Vol.43A(印刷中). (1997)

Watari Shiraki、Hiroshi Yamamoto 和 Kosuke Matsubara：“钢刚性框架桥墩的抗震可靠性评估”《结构工程杂志》第 43A 卷（出版中）。

白木渡・松保重之: "Fatique Reliability Analysis of Highway Bridges Using Live Load Simulation" Proceeding of ICASP-7 (7th International Conference on Application of Statistics and Probability in Civil Eng.). Vol.1. 379-386 (1995)

Watari Shiraki 和 Shigeyuki Matsuyasu：“使用活载模拟的公路桥梁疲劳可靠性分析”ICASP-7 论文集（第七届土木工程统计与概率应用国际会议），第 1 卷（1995 年）。

白木 渡: "鋼製ラーメン橋脚の耐震信頼性評価" 構造工学論文集. Vol.43A(印刷中). (1997)

Watari Shiraki：“钢刚性框架桥墩的抗震可靠性评估”《结构工程杂志》第 43A 卷（出版中）。

白木渡・松保重之: "交通荷重特性の変化が鋼道路橋の疲労信頼度に及ぼす影響評価" 構造工学論文集. Vol.42A. (1996)

Watari Shiraki 和 Shigeyuki Matsuyasu：“交通荷载特性变化对钢制公路桥梁疲劳可靠性的影响评估”《结构工程杂志》第 42A 卷。

白木 渡: "交通荷重特性の変化が鋼道路橋の疲労信頼度に及ぼす影響評価" 構造工学論文集. Vol.42A. 457-462 (1996)

Watari Shiraki：“交通荷载特性变化对钢公路桥梁疲劳可靠性的影响评估”《结构工程杂志》第 42A 卷（1996 年）。