基于钢筋坑蚀效应的近海隔震桥梁易损性分析

发布时间：2018-05-06 05:29

本文选题：桥梁工程 + 近海隔震桥梁　；参考：《中国公路学报》2016年08期

【摘要】：为了研究近海隔震桥梁在全寿命周期内锈蚀损伤后的抗震性能,对近海隔震桥梁进行基于钢筋坑蚀效应的地震易损性分析。考虑海蚀环境中氯离子对钢筋混凝土结构的腐蚀作用,建立钢筋坑蚀效应概率模型,结合拉丁超立方抽样方法建立近海隔震桥梁在不同服役年限下的随机样本模型。选取墩顶漂移率和支座剪应变分别作为墩柱和隔震橡胶支座的损伤指标,采用Pushover分析计算墩柱的损伤指标限值,利用增量动力分析(IDA)方法对随机样本模型进行非线性时程分析,提取样本模型在不同地震动作用下的响应值,采用回归分析得到近海隔震桥梁构件的概率地震需求模型。通过基于传统可靠度概率的易损性分析方法构建桥梁墩柱和隔震橡胶支座在全寿命周期内的易损性曲线,并结合一阶可靠度理论得到近海隔震桥梁在全寿命周期内的整体易损性曲线,评估其在全寿命周期内的抗震性能。结果表明:氯离子的腐蚀会导致桥梁墩柱的抗震性能不断降低,各构件达到不同极限破坏状态的超越概率逐渐变大,结构整体易损性曲线超越概率逐渐增大;相比于初始服役时,经过钢筋锈蚀80年后,严重破坏、完全破坏状态时结构的超越概率上限值增幅分别可达12%、10%,而超越概率下限值相比于初始服役增幅分别达到14%、12%。
[Abstract]:In order to study the seismic performance of the offshore isolated bridge after corrosion and damage in the whole life cycle, the seismic vulnerability analysis based on the effect of reinforcement pit erosion is carried out on the offshore isolated bridge. The corrosion effect of chloride ion on the reinforced concrete structure is considered, and the probability model of the reinforcement pit erosion is established, and the Latin hypercube sampling method is combined. A random sample model for offshore isolation bridges under different service years is established. The drift rate of the pier top and the shear strain of the support are selected as the damage indexes of the pier column and the isolated rubber bearing respectively. The Pushover analysis is used to calculate the limit of the damage index of the pier column, and the nonlinear time history of the random sample model is carried out by the incremental dynamic analysis (IDA) method. Analyzing the response values of the sample model under different ground motions, the probabilistic seismic demand model of the offshore isolated bridge members is obtained by regression analysis. The vulnerability curve of bridge pier columns and rubber bearings in the whole life cycle is constructed by the method of vulnerability analysis based on the traditional reliability probability, and the first order reliability is combined with the first order reliability. The overall vulnerability curve of the offshore isolated bridge in the whole life cycle is obtained, and the seismic performance of the bridge in the whole life cycle is evaluated. The results show that the corrosion of the chloride ion will cause the seismic performance of the bridge pier column to be reduced continuously, and the overcrossing probability of each component to the different ultimate failure states will gradually become larger, and the overall vulnerability of the structure is Qu Xianchao. Compared with the initial service, after 80 years of corrosion, after 80 years of corrosion, the upper limit of transcendental probability of the structure is 12%, 10% respectively, while the lower than the initial service increase is 14%, respectively, 12%.

【作者单位】：广州大学土木工程学院;广州大学工程抗震研究中心;
【分类号】：U445.73

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