中承式钢管混凝土拱桥桥面板疲劳性能分析

发布时间：2018-05-20 09:53

本文选题：中承式钢管混凝土拱桥 + 车桥耦合振动　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：早期建造的中承式钢管混凝土拱桥,很多的构造型式都是由吊杆悬吊横梁,然后在横梁之间直接铺设桥面板,而并没有设置相应的纵梁。这使得桥面系整体性较差,刚度偏低,桥梁整体的动力性能较差,振动幅度大,持续时间长,能量耗散慢,对于桥梁的使用性、耐久性和安全性都很不利。在这种情况下,实际运营中桥面发生了很多病害,如桥面松散、开裂、破损甚至出现漏洞等严重问题。然而桥梁已经建成,再添加相应的纵梁无论从设计还是施工等其它方面都很难实现。所以,就要全面地分析桥梁的性能,进而从其它方面找到提高桥梁桥面系动力性能的方法。本文从引起桥面损伤的其中一个原因——桥面板的疲劳性能方面来分析桥面系的性能,使用分离式车桥耦合振动计算方法来研究结构的动力响应,并分析了多种因素对于桥面板疲劳性能的影响。首先,本文所使用的工程背景桥梁为坐落在辽宁省省会沈阳市浑河上的长青大桥,对桥梁中跨进行有限元建模,选取了相应的平面四自由度车辆模型以及桥面不平整度计算模型,结合自编程序对桥梁的车桥耦合振动进行了细致的计算分析。分析了桥梁在车辆作用下的动力响应,如动位移、动力冲击系数以及动弯矩等。通过分析,发现处于横梁上的桥面板上缘处于异号的拉-压应力循环作用下,相比横梁间板中心的只受压应力产生更大的桥面板疲劳损伤。又分析了行车速度与桥面不平整度对桥梁动力性能的影响,发现不平整度越差,桥梁的动力响应越大;而行车速度的不同对于桥梁动力响应没有明显的变化规律。然后,着重从桥面板疲劳性能这一方面对桥梁桥面系进行了研究。计算分析了横梁宽度、桥面板厚度、桥面不平整度、行车速度等因素对于桥面板疲劳性能的影响。分析得知,横梁宽度越大,桥面板疲劳寿命越高;桥面板厚度越大,桥面板疲劳寿命越高,且厚度达30cm后疲劳寿命增幅变缓;桥面不平整度越差,桥面疲劳性能越低,建议至少保持B级平整度以上水平;而行车速度对桥面板疲劳性能的影响没有明显规律。最后,给出了加固前长青桥的静、动力检测结果,以及添加钢纵梁等加固措施以及效果评价。又详细阐述了新近提出的剪刀式阻尼器加固方式以及其改进后的方案,并分别分析了其加固效果,发现改进后的剪刀式阻尼器比之前的加固效果又有了一定的提高。
[Abstract]:In the early construction of the middle bearing type concrete filled steel tube arch bridge, many structural types were suspended by suspended beams, and then the bridge deck was laid directly between the beams, and the corresponding longitudinal beams were not set. This made the deck system less integral, the stiffness was low, the overall dynamic energy of the bridge was poor, the amplitude of the vibration was large, the duration was long, and the energy dissipation was long. Slow, the use, durability and safety of the bridge are very bad. In this case, there are many diseases in the actual operation of the bridge, such as the loose bridge surface, cracking, breakage and even loopholes. However, the bridge has been built and the corresponding longitudinal beam is difficult to realize from other aspects, such as design and construction. It is necessary to analyze the performance of bridges in an all-round way, and then find ways to improve the dynamic performance of bridge deck system from other aspects. In this paper, the performance of bridge deck system is analyzed from the fatigue performance of bridge deck, which is one of the causes of bridge deck damage, and the dynamic response of the structure is studied by the coupled vibration calculation method of the separation type vehicle bridge. The influence of various factors on the fatigue performance of the bridge deck is analyzed. First, the bridge used in this paper is the Changqing bridge located on the Hun River in Shenyang, the capital of Liaoning province. The finite element modeling is carried out on the middle span of the bridge. The corresponding plane four degree of freedom vehicle model and the calculation model of the uneven deck of the bridge deck are selected. The coupled vibration of the bridge is carefully calculated and analyzed. The dynamic response of the bridge under the action of the vehicle, such as the dynamic displacement, the dynamic impact coefficient and the dynamic bending moment, is analyzed. Through the analysis, it is found that the upper edge of the bridge deck on the beam is under the action of the tensile compressive stress on the beam and the only compression of the center of the beam between the beams. Stress produces more fatigue damage of bridge deck. The effect of driving speed and uneven deck on bridge dynamic performance is analyzed. It is found that the worse the uneven degree is, the greater the dynamic response of bridge is, and the difference of driving speed is not obvious to the dynamic response of bridge. Then, the stress of bridge deck is mainly from the fatigue performance of bridge deck. The bridge deck system is studied. The influence of the width of the beam, the thickness of the bridge deck, the unevenness of the bridge deck and the speed of the bridge on the fatigue performance of the bridge deck is calculated and analyzed. The analysis shows that the greater the width of the beam, the higher the fatigue life of the bridge deck, the greater the thickness of the bridge deck, the higher the fatigue life of the bridge deck, and the increase of fatigue life after the thickness of 30cm. The slower the amplitude and the lower the deck roughness, the lower the fatigue performance of the bridge deck, it is suggested that at least the level of B level is maintained at least, and the driving speed has no obvious influence on the fatigue performance of the bridge deck. Finally, the static and dynamic testing results of the Changqing bridge before reinforcement and the reinforcement measures of the steel longitudinal beam and the effect evaluation are given in detail. The newly proposed reinforcement method of the scissors type damper and its improved scheme are described, and the reinforcement effect is analyzed respectively. It is found that the improved scissors damper has a certain improvement over the previous reinforcement effect.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.4;U448.22

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