基于全寿命设计的钢筋混凝土结构安全度研究与应用

发布时间：2018-09-13 09:29

【摘要】：由于我国设计规范并未充分考虑到结构老化后的性能状态,随着工程设计理论的不断完善,对混凝土框架结构的全寿命周期可靠度理论的研究成为一大热点。本文对混凝土框架结构的全寿命抗震可靠度进行研究,主要的研究工作和取得的成果如下：(1)由于不同使用期的荷载取值不同,本文根据地震概率的模型,推导了不同服役期地震烈度、加速度、地震影响系数最大值和重现期取值。以50年地震作用为基准,提出了地震影响系数最大值修正系数、峰值加速度修正系数、烈度修正系数,推导了公式。为了便于公式的应用,本文对公式中的参数用SPSS软件进行拟合,并进行误差分析,证明公式的可靠性。(2)以结构的层间位移角作为结构的性能指标,对框架结构采用增量动力分析方法(IDA)计算结构抗震可靠度进行介绍,并给出了采用最小抗力法计算结构全寿命周期抗震可靠度的计算思路。(3)分析了钢筋锈蚀劣化模型、损伤混凝土本构模型、节点滑移模型,并得到了框架结构在全寿命周期内的计算参数。通过对不同服役阶段结构在相同地震作用下的可靠度进行比较表明,结构的服役年限越长,结构的可靠度越低,且降低的幅度随着使用年限的增大和地震作用的增大越来越快。(4)采用最小抗力法对结构进行全寿命周期的抗震可靠度计算,并与未考虑材料性能退化结构的可靠度进行比较。结果表明考虑材性退化后结构的失效概率大于不考虑材性退化的失效概率,且两者的差值随着设计使用年限的增加越来越大。(5)当既有结构的性能不能满足抗震性能要求时需要对结构进行加固,本文归纳了结构维修费用与结构加固可靠度的关系式,总结了结构失效费用的计算方法,给出了结构维修与拆除准则与维修方案的决策模型。采用该模型对框架算例进行加固优化,得到了加固最优可靠度,验证了该模型的实用性。
[Abstract]:Because the design code of our country has not fully considered the performance state of the structure after aging, with the continuous improvement of the engineering design theory, the research on the whole life cycle reliability theory of concrete frame structure has become a hot topic. In this paper, the whole life seismic reliability of concrete frame structure is studied. The main research work and the results obtained are as follows: (1) because the load values of different life are different, according to the model of earthquake probability, The seismic intensity, acceleration, maximum value of seismic influence coefficient and the value of recurrence period are deduced. Based on the seismic action of 50 years, the maximum correction coefficient, the peak acceleration correction coefficient and the intensity correction coefficient of the seismic influence coefficient are put forward, and the formula is derived. In order to facilitate the application of the formula, the parameters of the formula are fitted by SPSS software, and the error analysis is carried out to prove the reliability of the formula. (2) taking the displacement angle between the layers of the structure as the performance index of the structure, In this paper, the incremental dynamic analysis method (IDA) is used to calculate the seismic reliability of frame structure, and the method of minimum resistance is given to calculate the seismic reliability of the whole life cycle of frame structure. (3) the corrosion and deterioration model of steel bar is analyzed. The damage concrete constitutive model, the node slip model, and the calculation parameters of the frame structure in the whole life cycle are obtained. By comparing the reliability of structures in different service stages under the same earthquake action, it is shown that the longer the service life of the structures, the lower the reliability of the structures. With the increase of service life and earthquake action, the decreasing amplitude is faster and faster. (4) the seismic reliability of the whole life cycle of the structure is calculated by using the method of minimum resistance, and compared with that of the structure without considering the degradation of material performance. The results show that the failure probability of the structure considering the degradation of wood property is greater than that of the structure without considering the degradation of wood property. And the difference between the two is increasing with the increase of design life. (5) when the performance of the existing structure can not meet the requirements of seismic performance, it is necessary to strengthen the structure. This paper summarizes the relationship between the maintenance cost of the structure and the reliability of the structure. The calculation method of the failure cost of the structure is summarized, and the decision model of the maintenance and demolition criteria and the maintenance scheme is given. The model is used to optimize the reinforcement of the frame, and the optimal reliability is obtained, and the practicability of the model is verified.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU375

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