大跨度连续梁桥动力特性分析

发布时间：2018-03-29 22:06

本文选题：连续梁桥　切入点：动力特性　出处：《大连理工大学》2014年硕士论文

【摘要】：近几十年来桥梁工程在我国得到了快速的发展,连续梁桥由于其自身的优点而得到了广泛的应用。大跨度续连续梁桥在最大施工悬臂阶段结构刚度小于成桥状态,在风荷载作用下可能发生较大振幅的风致振动,有必要对最大悬臂施工阶段进行抗风分析。另外我国是地震灾害较为严重的国家,一旦发生地震,结构可能遭受损坏或者倒塌,需要对结构进行抗震设计。本文以大连市普湾新区跨海大桥为对象,对其进行了抗风和抗震研究,本文主要的的工作和结论如下： (1)简单介绍了构自振特性的分析方法,对普湾大桥的成桥状态和最大悬臂施工状态的自振特性进行了分析计算,得到了前十阶阵型,为进一步的抗风和抗震研究打下基础。 (2)按照规范反应谱法和时程分析法对跨海大桥进行了抗震分析,并对比研究这两种抗震设计方法。 (3)简述了粘滞阻尼器的耗能原理和恢复力模型,并采用粘滞阻尼器对本桥进行减震设计研究,结果表明粘滞阻尼器有效地消耗地震输入能,减小结构地震响应。 (4)基于CFD技术,对普湾大桥的周围绕流场进行了三维非定常数值模拟,研究了海平面干扰下的主梁气动特性,结果表明由于普湾大桥主梁距离海平面较小,海平面对主梁周围的流场有强烈的干扰作用,大幅增加了主梁断面三分力系数的脉动值,而对三分力系数的平均值影响较小。同时基于模拟得到的流场分布对计算结果进行了原理分析。 (5)模拟了湍流风场下普湾大桥的非定常绕流场,计算结果表明湍流风场对主梁平均阻力系数和平均扭矩系数无明显影响,增大了平均升力系数；湍流风场均在一定程度上增大了三分力系数的脉动值。 (6)实现了联合运用数值模拟技术和结构有限元计算对普湾大桥风振响应的协同分析,结果表明非稳态时域分析得到的最大悬臂端位移响应峰值明显比仅仅考虑静风荷载要大,脉动风对结构动力响应的影响是不能够忽略的。 (7)通过数值模拟得到风荷载作用下桥面风速比分布,可以看出风速会在距离桥面2-3m左右位置的流场分离剪切层位置发生突变,从而导致车辆行驶过程中产生较大的侧倾力矩,这对行车安全是极为不利,应予以重视。
[Abstract]:In recent decades, the bridge engineering has obtained rapid development in our country, the continuous girder bridge is widely used because of its own advantages. The large span continuous beam bridge construction continued in the maximum cantilever stage structure stiffness is less than the bridge, under wind load may occur with large vibration amplitude, a the necessary wind analysis on the maximum cantilever construction stage. In addition to our national earthquake disaster is more serious, once the earthquake, the structure may suffer damage or collapse, the need for the seismic design of the structure. This paper takes Dalian city puwan New District Sea Bridge as the object, has carried on the wind and seismic research, this paper. The work and conclusions are as follows:
(1) briefly introduce the analysis method of the construction self vibration characteristics, analyze and calculate the natural vibration characteristics of the Pu Wan Bridge and the maximum cantilever construction state, get the first ten tier formation, and lay the foundation for further research on wind resistance and earthquake resistance.
(2) the seismic analysis of the cross sea bridge is carried out according to the standard response spectrum method and the time history analysis method, and the two seismic design methods are compared and studied.
(3) the energy dissipation principle and restoring force model of viscous dampers are briefly described. The viscous damper is applied to the design study of the bridge. The results show that viscous damper effectively consumes seismic input energy and reduces the seismic response of the structure.
(4) based on the CFD technology, the general around the Bay Bridge flow around the three-dimensional unsteady numerical simulation of the gas beam sea level under the disturbance of the dynamic characteristics, results show that because the main beam Pu Bay Bridge from the sea level is smaller, the sea level on the flow field around the interference effect of strong beam, a substantial increase in the ripple girder section three component coefficient value, while the average value has little influence on the three component coefficients. At the same time the distribution of flow field simulation is conducted based on the principle analysis of the calculation results.
(5) the unsteady flow field simulation of turbulent wind field under the Cape Bay Bridge, the calculation results show that the turbulent wind field has no obvious effect on the average drag coefficient of girder and average torque coefficient, increase the average lift coefficient; turbulent wind field are in a certain extent increase the pulsation of three component coefficient values.
(6) for the combined use of numerical simulation technology and finite element calculation of the collaborative analysis of general bay bridge wind vibration response analysis, results show that the largest cantilever displacement response peak is more obvious than only considering the static wind load to obtain large non steady time, fluctuating wind effect on the dynamic response can not be ignored.
(7) obtained by numerical simulation under wind load of bridge wind speed distribution, we can see that the wind will occur in the flow field of the separated shear layer position from the bridge about 2-3m the location of mutations, resulting in greater roll torque during the running process of the vehicle, the traffic safety is extremely unfavorable, which should be paid attention to.

【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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