营运斜拉桥检测与安全评价

发布时间：2018-01-20 23:41

本文关键词： 斜拉桥营运状态检测静载试验动载试验　出处：《石家庄铁道大学》2015年硕士论文　论文类型：学位论文

【摘要】：斜拉桥以适用跨径范围广、造型美观多样等特点,至从上世纪80年代以后,便首先在我国研究和推广使用,目前,已经建造了上百座,而且跨度纪录也不断被刷新。但由于受当时设计标准、施工水平、长期超载、养护维修不善、偶然事故、以及构造认识不足等因素的综合影响,一些桥梁在使用期限内就出现了斜拉索老化、锚固失效等病害,很多桥梁都进行了换索施工,仍有大批在役桥梁需要加强维护及加固。本文以某斜拉桥工程为背景,重点对桥梁营运状态进行检测及安全性能评定具有较重要的工程意义。本文以某大桥主跨斜拉桥为依托,对该桥进行了常规检测和特殊检测,依据检测结果对桥梁的工作状态进行了初步判定;按规范法对桥梁承载能力进行了复核,依据规范对桥梁进行了综合评定,采用有限元软件建模,对桥梁静动力性能进行了模拟计算,与通过静载、动载试验,深入考察了桥梁的工作行为,得出了桥梁在典型最不利加载状态时的响应,结果表明:主要测点挠度、应力最大效验系数为0.85,最大残余变位和应变均小于20%,在最大试验荷载作用下,斜拉桥跨梁底没有出现裂缝,桥梁基础未发生不稳定沉降变位。脉动试验结果表明,大桥主桥斜拉桥竖向弯曲自振频率为1.76Hz,大于理论计算频率,说明该桥刚度满足设计要求;主梁前3阶竖向振型的阻尼比分别为4.32%、2.59%、3.53%,跨中截面实测冲击系数1+μ介于1.05~1.12之间,其值在同类桥梁常值范围内。由此可知,该大桥主桥斜拉桥承载能力满足设计荷载等级汽车-20、挂-100的要求,结构处于弹性工作状态。
[Abstract]:Since -20s, cable-stayed bridge has been studied and popularized in our country for its wide span and various shapes. At present, hundreds of cable-stayed bridges have been built. But due to the design standards, construction level, long-term overload, poor maintenance and maintenance, accidental accidents, and lack of structural awareness. Some bridges have been damaged by the aging of stay cables and the failure of anchoring during the service life. Many bridges have carried out cable replacement construction. There are still a large number of existing bridges need to be strengthened and strengthened. This paper takes a cable-stayed bridge project as the background. It is of great engineering significance to test the operation state and evaluate the safety performance of the bridge. Based on the cable-stayed bridge of a certain bridge, this paper carries on the routine inspection and the special inspection to the bridge. Based on the test results, the working state of the bridge is preliminarily determined. The bearing capacity of the bridge is checked according to the code method, the bridge is evaluated synthetically according to the code, the static and dynamic performance of the bridge is simulated and calculated by the finite element software, and the static load and dynamic load test is carried out. The working behavior of the bridge is thoroughly investigated and the response of the bridge under the typical most unfavorable loading state is obtained. The results show that the deflection of the main measuring points and the maximum effective coefficient of stress are 0.85. The maximum residual displacement and strain are less than 20. Under the maximum test load, there are no cracks at the bottom of the span beam of the cable-stayed bridge, and no unstable settlement displacement occurs on the bridge foundation. The pulsating test results show that. The vertical bending natural vibration frequency of the main cable-stayed bridge is 1.76 Hz, which is larger than the theoretical calculation frequency, which shows that the stiffness of the bridge meets the design requirements. The damping ratio of the first three vertical modes of the main beam is 4.32 and 2.593.53, respectively, and the measured impact coefficient of the mid-span section is between 1.05 and 1.12. The bearing capacity of the cable-stayed bridge of the main bridge can meet the requirements of design load grade automobile -20 and hang-100, and the structure is in an elastic working state.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446;U448.27

【参考文献】