叠合柱高墩大跨连续刚构桥概率地震易损性及风险分析

发布时间：2018-01-11 07:22

本文关键词：叠合柱高墩大跨连续刚构桥概率地震易损性及风险分析　出处：《西南交通大学》2015年博士论文　论文类型：学位论文

【摘要】：连续刚构桥因其跨越能力大、地形适应性强、造价适中等优势,成为西部山区跨越峡谷地形的主要桥型。由于受地形限制,连续刚构的桥墩越来越高,不断刷新原有记录,而由于钢筋混凝土自重大、延性差的缺点,已经成为桥墩向更高发展的瓶颈。采用钢管混凝土叠合柱作为大跨径连续刚构桥的桥墩,是突破这一瓶颈的一个新的尝试。由于叠合柱材料的本构模型、力学性能和破坏方式等均与钢筋混凝土有较大差异,对其抗震性能和损伤评估缺乏系统的研究。因此,深入系统地研究钢管混凝土叠合柱高墩大跨径连续刚构桥的抗震性能和损伤规律,对这一桥梁新型结构的设计和推广应用,均具有重要的意义。本文采用数值模拟和概率解析方法,对叠合柱高墩大跨径连续刚构桥的概率地震易损性分析和概率地震风险分析进行研究,主要研究内容如下：(1)应用纤维模型对50个相同尺寸不同强度的叠合柱截面样本进行偏心受压破坏的全过程数值模拟,获得截面的P-M-φ曲线。根据样本数值模拟的破坏状态,将叠合柱截面划分为弹性和非弹性、需要修复和不需要修复、可修复和不可修复、倒塌和不倒塌四个性能目标和无损伤、轻微损伤、中等损伤、严重损伤、完全损伤五个损伤状态。根据截面不同纤维材料破坏应变在P-M-φ曲线上的映射,考虑偏心受压状态轴力的变化,不考虑纤维材料参数的不确定性,建立了以轴力为变量的叠合柱截面确定性抗震能力模型。同时,考虑纤维材料参数的不确定性,根据50个抽样样本偏心受压数值模拟结果,分析不同损伤状态曲率指标的统计分布规律,建立以轴力为变量的叠合柱概率抗震能力模型。(2)以一座跨径为105m+200m+200m+105m叠合柱高墩连续刚构桥为例,选择17条符合场地特征的实际地震波,以PGA为地震动参数,考虑P-A效应,分别输入每条地震波进行动力弹塑性时程分析和其中的一条地震波进行IDA分析,获得纵、横向地震作用下地震需求沿墩高的分布规律,确定桥墩的最不利截面作为地震需求分析的控制截面。考虑桥墩截面材料参数和地震动的不确定性,分别输入17条实际地震波进行IDA计算,对计算结果进行统计分析,建立叠合柱桥墩控制截面以PGA为变量的概率地震需求模型。(3)应用可靠度理论,分别推导考虑结构和地震动不确定性以及只考虑地震动不确定性的地震易损性函数解析表达式。根据概率抗震能力和概率抗震需求的参数统计值,获得纵、横向地震输入下叠合柱高墩控制截面的地震易损性曲线,分析了墩柱发生不同损伤的规律以及结构不确定性对易损性曲线的影响。根据桥墩控制截面的易损性曲线,用一阶界限法估算了叠合柱高墩大跨径连续刚构桥结构体系发生不同损伤的超越概率,获得桥梁结构体系的易损性曲线。(4)根据地震动参数概率模型,研究了我国现有不同地震基本烈度地区的地震危险性,并根据概率地震易损性分析结果和概率风险函数解析表达式,对叠合柱高墩连续刚构桥的概率地震损伤风险和概率地震需求风险进行分析,并对两种风险概率进行对比。根据年地震风险分析的结果,获得设计基准期内叠合柱桥墩的地震风险概率和结构体系的地震风险概率,并根据我国现行公路桥梁抗震设防标准,对叠合柱高墩大跨径连续刚构桥的抗震性能进行评估。
[Abstract]:Because of the continuous rigid frame bridge with large span capacity, strong adaptability of terrain, moderate cost and other advantages, become the main bridge across the western mountain canyon terrain. Due to the limitation of terrain, and pier continuous rigid frame is high, constantly refresh the original records, and because the weight of reinforced concrete, ductility is poor, has become a bottleneck of pier high development. The concrete filled steel tubular columns as long-span continuous rigid frame bridge is a new attempt to break the bottleneck. The constitutive model of laminated column material, mechanical properties and failure modes were compared with reinforced concrete, the lack of systematic research on the seismic performance and damage the evaluation. Therefore, the seismic performance and damage of the deep and systematic research on concrete filled steel tubular columns of high pier and long-span continuous rigid frame bridge, wide application of the design of this bridge and push the new structure, are Is of great significance. Based on the numerical simulation and probability analytical method of probability analysis of seismic fragility analysis and seismic risk probability of laminated column of high pier and long-span continuous rigid frame bridge, the main research contents are as follows: (1) application of fiber model the same size with different strength of laminated column cross-section sample of 50 numerical simulation of the whole process of eccentric compression failure, P-M- diameter curve section. According to the numerical simulation of the damage state of the sample, the column section is divided into elastic and non elastic, does not need to need to repair and repair, repair and repair, do not collapse and the collapse of four performance targets and no damage, minor damage, moderate damage, serious damage, and five damage state completely damage. According to the failure strain in the P-M- mapping on the curve sections of different fiber materials, changes into the state of eccentric compression axial force, without considering the fiber The material parameter uncertainty is established based on the axial force of the variable cross-section laminated column seismic capacity of the deterministic model. At the same time, considering the uncertainty of parameters of fiber materials, numerical simulation results based on a sample of 50 eccentric compression, analysis of statistical distribution of curvature index with different damage conditions, to establish the axial force of variable superimposed column probabilistic seismic capacity model. (2) with a span of 105m+200m+200m+105m columns high pier continuous rigid frame bridge as an example, choose 17 to meet with the site characteristics of the actual seismic wave, PGA seismic parameters, considering the P-A effect, respectively, each input seismic wave dynamic elastic-plastic time history analysis of a seismic wave and the IDA analysis, obtain the longitudinal, transverse earthquake under the seismic demand distribution along the height of the pier, the control section as the seismic demand analysis to determine the most dangerous section of the bridge pier. Considering the pier section material The material parameters and the uncertainties of the earthquake input, respectively 17 actual seismic wave IDA calculation, the results of the statistical analysis, the establishment of laminated column pier section with PGA as the probabilistic seismic demand model variables. (3) the application of reliability theory are derived considering structure and seismic uncertainties and only considering the uncertainty of seismic vulnerability analytic expression. According to the statistical parameters of probabilistic seismic capacity and probability seismic demand value, obtain the longitudinal, transverse seismic input superimposed seismic fragility curve of high pier column control section, analysis of the influence of different damage patterns and pier structure uncertainty on the vulnerability curve according to the fragility curves of pier control section, in order to estimate the probability limit method different damage structure of laminated column of high pier and long-span continuous rigid frame bridge, the bridge Fragility curves of beam structure system. (4) according to the motion parameters of the probabilistic model, studied the seismic risk of the existing basic intensity of different seismic regions in China, and according to the probability of seismic vulnerability analysis and risk probability function analytical expressions of laminated column of high pier continuous rigid frame bridge seismic damage probability and probability of earthquake risk demand risk analysis, and compares the two kinds of risk probability. According to the earthquake risk analysis results, the seismic risk probability of the design reference period of laminated column pier seismic risk probability and structure system, and according to the current highway bridge in China seismic fortification level, seismic performance of laminated column with high pier and large span continuous rigid frame bridge is evaluated.

【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U442.55

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