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绵竹市回澜匝道桥抗震分析
Seismic Response Analysis of Huilan Ramp Bridge in Mianzhu
【作者】 王旭阳;
【导师】 唐继舜;
【作者基本信息】 西南交通大学 , 桥梁与隧道工程, 2010, 硕士
【摘要】 随着交通事业的发展和人们审美意识的提高,在新建公路、改建公路以及城市道路中,需要修建越来越多的曲线梁桥。在发生地震时,曲线梁桥的震害破损问题越来越突出。本文以小曲率半径的曲线梁桥为对象,研究了曲线梁桥一些动力和抗震特性,得出了对小曲率曲线梁桥抗震设计有指导意义的结论。具体研究内容如下:(1)采用有限元梁单元模型,模拟和分析了回澜匝道曲线梁桥的振型形状、周期、频率。通过振型贡献率讨论,找出了抗震分析时小曲率曲线梁桥所要取的合理振型阶次。(2)对回澜匝道曲线梁桥进行了单、双向反应谱分析。通过改变地震输入角度对结构进行单向反应谱分析,找出了各墩底单向反应谱下弯矩、剪力最不利输入角度和最不利值,对比了不同振型组合下单向反应谱结果。采用相互正交的两列反应谱改变地震输入角度,对结构进行双向反应谱分析。对比了SRSS和30%不同空间组合原则下的双向反应谱结果。比较了最不利输入角度下单、双向反应谱结果。(3)对回澜匝道曲线梁桥进行了单、双维时程分析。采用设计反应谱,利用随机相位角法生成了人工地震波,并对比了两列人工地震波单维输入结果。通过改变地震输入角度对结构进行单维时程分析,找出了各墩底单维地震输入下弯矩、剪力最不利输入角度和最不利值,对比了单向反应谱与单维地震输入结果。对比了不同地震波下结构单维时程分析结果。采用相互正交的两列地震波,改变地震输入角度对结构进行双维时程分析,对比了单双维地震输入结果。对比了不同地震波下结构双维时程分析结果。单、双维时程分析时采用了两种方法寻找最不利输入角度和最不利值,比较了两种方法时程结果。(4)对回澜匝道桥震前、加固后动力特性进行分析,找出了震前、加固后结果出现差别的原因。
【Abstract】 With the development of transport and people’s aesthetic consciousness, more and more curved bridge need to be builded. In the event of an earthquake, more and more problems of damage of the curve bridge are arised in the new roads, rebuilt roads and urban roads. In this dissertation, the cuvred bridge with small curvature reradius is researched. A number of dynamic and seismic characteristics of the curved bridge are studied. Some conclusions to guide the design of the small curvature curved bridge are obtained. Specific contents are as follows:(1) Vibration mode shapes, period, frequency of HuiLan Bridge are simulated and analyzed with finite element beam element model.With discussions of mode contribution ratios, the reasonable number of modes of small curvature curved girder bridge is founded in the seismic analysis.(2) HuiLan Bridge is analyzed with single and two-dimensional response spectrum. By changing the angle of seismic waves in the single-dimensional response spectrum analysis, the most disadvantaged angle and the most negative value of bending moment, shear are founded in the analysis. The single dimensional response spectrum results is contrasted in different modes combinations.By using two orthogonal response spectrum and changing the angle of seismic waves,the bridge is analyzed with two-dimensional response spectrum. The two-dimensional response spectrum results are contrasted in different space combination of SRSS and 30% principle. The single and two-dimensional response spectrum results are contrasted in the most disadvantaged angle.(3) HuiLan Bridge is analyzed with single and two-dimensional Time-History analysis method. By using design response spectrum and random phase angle method, artificial seismic waves are generated. The single-dimensional Time-History analysis results are contrasted in two artificial seismic waves. By changing the angle of seismic waves in the single-dimensional Time-History analysis, the most disadvantaged angle and the most negative value of bending moment, shear are founded in the analysis. The single dimensional Time-History analysis results are compared with the single dimensional response spectrum results. The single dimensional Time-History analysis results are contrasted in the different seismic waves. By using two orthogonal seismic waves and changing the angle of seismic waves,the bridge is analyzed with two-dimensional Time-History analysis method. The single dimensional Time-History analysis results are compared with the two-dimensional Time-History analysis results. The two-dimensional Time-History analysis results are contrasted in the different seismic waves. Two methods are used to find the most disadvantaged angle and the most negative value in the single and two-dimensional Time-History analysis.The results in the two methods are contrasted.(4) The HuiLan Bridge dynamic characteristics is analyzed before earthquake and after bridge reinforcement. The reasons of differdnt seismic analysis results before and after bridge reinforcement is finded out.
【Key words】 Curved Bridge; Seismic Analysis; Response spectrum; Time-History; The most disadvantaged angle;