连续梁桥车桥系统随机地震响应概率分布及动力可靠度研究

发布时间：2018-10-13 12:05

【摘要】：地震对桥梁工程的损害严重影响了人们的日常生活和灾后工作,又存在很大几率威肋、着桥上列车的行车安全性。因此,进行地震响应分析十分必要。地震动的三个基本振动特性为振幅大小、频谱特性、持续时间,对地震反应分析起着决定性作用,而三个特性均有显著的随机性,因此,将随机振动理论应用于桥梁地震分析是十分合理的。本文基于随机振动理论,以某铁路桥五跨连续梁桥为例,建立列车-轨道-桥梁耦合振动模型,采用团队自主研发的列车-轨道-桥梁-地震分析程序(TTBSAS),研究了随机地震荷载作用下随机系统响应的概率统计特性及动力可靠度。本文主要工作及成果如下：(1)考虑多点地震动的空间变化特性,即行波效应、局部场地效应、部分相干效应、衰减效应,将Clough-Penzien谱作为自功率谱函数,屈铁军-王君杰模型作为相干函数,合成空间相关非平稳地震波。并把自功率谱函数中的强度因子与滤波参数作为随机参数,采用乘同余法生成人工合成地震波样本；(2)应用Monte-Carlo模拟方法对人工合成的地震波样本进行响应概率统计分析。结果表明,车辆响应与极值Ⅰ型分布吻合较好,包括车体加速度、脱轨系数、轮重减载率,桥梁跨中横向位移响应与极值Ⅰ型分布吻合较好,竖向位移和加速度响应与对数正态分布吻合较好。列车行车速度和地震动行波效应均对响应的概率统计特性不产生影响；(3)根据响应的概率统计特性曲线,得到桥梁跨中截面各响应动力可靠度对应的界限值和基于列车安全性准则的体系动力可靠度对应的列车响应界限值。结果表明,响应界限值随可靠度的增大而增大,按照传统评价列车行车安全性和舒适性的指标,随机地震荷载作用下满足可靠度要求的前提不会影响行车安全性,但对舒适性有一定影响。
[Abstract]:The damage caused by earthquake to bridge engineering has seriously affected people's daily life and post-disaster work, and there is a great chance of the train safety on the bridge. Therefore, the seismic response analysis is very necessary. The three basic vibration characteristics of ground motion are amplitude, frequency spectrum and duration, which play a decisive role in seismic response analysis. It is very reasonable to apply random vibration theory to bridge seismic analysis. Based on the theory of random vibration and taking a five-span continuous beam bridge of a railway bridge as an example, a train-track bridge coupling vibration model is established in this paper. The probabilistic and statistical characteristics and dynamic reliability of stochastic system response under random earthquake loads are studied by using the Train-track Bridge-Seismic Analysis Program (TTBSAS),) developed by the team. The main work and results are as follows: (1) considering the spatial variation characteristics of multipoint ground motion, that is, traveling wave effect, local site effect, partial coherence effect and attenuation effect, the Clough-Penzien spectrum is taken as the self-power spectrum function. Qu Tiejun-Wang Junjie model is used as a coherent function to synthesize spatially correlated nonstationary seismic waves. The intensity factor and filter parameters in the self-power spectrum function are taken as random parameters and the synthetic seismic wave samples are generated by multiplicative congruence method. (2) the response probability statistical analysis of synthetic seismic wave samples is carried out by using Monte-Carlo simulation method. The results show that the vehicle response agrees well with the extreme type I distribution, including the acceleration of the car body, the derailment coefficient, the wheel load reduction rate, the lateral displacement response of the bridge in the middle of the span and the extreme value type I distribution. The vertical displacement and acceleration response agree well with the logarithmic normal distribution. Both the train speed and the traveling wave effect of ground motion have no effect on the probability and statistical characteristics of the response. (3) according to the probability and statistical characteristic curve of the response, The boundary values corresponding to the dynamic reliability of each response of the middle section of the bridge and the train response boundary value corresponding to the dynamic reliability of the system based on the train safety criterion are obtained. The results show that the response limit value increases with the increase of reliability. According to the traditional evaluation index of train running safety and comfort, the premise of meeting the reliability requirement under random earthquake load will not affect the driving safety. However, there is a certain impact on comfort.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55

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