【作者】 程书剑；

【导师】 刘西拉； 方从启；

【作者基本信息】 上海交通大学 ， 结构工程， 2009， 硕士

【摘要】 随着大跨度桥梁的大量建设,大型桥梁的结构安全问题越来越受到重视。上海市在大型桥梁建设方面走在全国前列,但却没有比较系统科学的安全监测与管理方法。基于上海市的交通特点和环境特点,本文提出了上海市大型桥梁特别是大型斜拉桥的监测重点,并且总结了桥梁结构损伤的类型及其监测方法。在桥梁的安全监测中,首先需要解决两个关键问题:1、监测指标对损伤是否足够敏感。2、监测系统自身的可靠性。目前的自动监测方法,多是以动力特性作为最重要的指标,其中自振频率频率是最为重要的基本动力指标。本文将从构件和结构两个层次、利用结构动力学和有限元方法分析了动力特性对损伤、环境、边界条件等因素的敏感程度及其机理。从而证明了动力指标对损伤不敏感,易于被其他因素掩盖。因此,在桥梁的安全监测中,监测项目必须全面、合理,而且目前的自动监测水平仍需要人工检测手段的配合。在监测过程中,不可避免地需要对传感器进行更换。对埋入式传感器,则需要研究其替换方法和各代检测或监测数据的衔接问题。本文在这方面做了有益的探索并取得了一定成果,取得了两项中国实用新型专利并通过试验进行了验证。在前面工作的基础上,本文结合上海市大型桥梁的特点论证了上海市大型桥梁安全监测所需监测的项目及其监测方法。更多还原

【Abstract】 With the extensive building of large-scale bridges, more and more attention has been paid to the safety of the bridge structures. Shanghai is leading in the construction of long span and large scale bridges in China. But up to now there is no scientific and systematic method for the monitoring and administrating of the existing bridges.In the present thesis, based on both transportation and environment characteristics of Shanghai, the key points of the monitoring system for the large-scale bridges, primarily cable-stayed bridges, are presented, and the types of structuaal damage and the monitoring methods are summarized.In safety monitoring of large-scale bridges, two problems must be resolved: a) the monitored indexes are not enough sensitive to damages. b).the reliability of monitor system itself.In most of automatic monitoring methods, the dynamic behavior of a structure is always taken as the most important consideration. In the present thesis, the sensitivity of the dynamic features to damages, environment and boundary conditions are analyzed from member level and structural level as needed. The results proved that the dynamic features are not sensitive enough to damage and uaually are covered by the influence of other factors. Therefore, in this case, the monitored terms should be in global vision and reasonable. It seems that the automatic monitoring methods still need to be cooperated by manual inspecting.During monitoring process, it is inevitable to renew the existing sensors owing to the relatively short life time of the monitoring sensors. It is very urgent to develop a reasonable process for the substitution of the embedded monitoring sensors and to keep data continuously and smoothly. These problems, to some extent, have been resolved in the present thesis. Finally, discussion is presented on how to build a human-machine system for a realistic monitoring system.更多还原