【作者】 李军；

【导师】 肖岩；

【作者基本信息】 湖南大学 ， 土木工程， 2016， 硕士

【摘要】 地震是一种不可预见的自然灾害,结构在地震作用下会发生不同程度的损坏,严重危及人们的生命及财产安全。地震作用是一个往复循环的过程,结构在整个过程中即使没有产生很大的反应,但是由于往复作用下的累积损伤可能使结构破坏。钢管混凝土柱由于具有许多优点而广泛应用于高层建筑、工业厂房及桥梁结构中。目前对于钢管混凝土柱抗震性能的评估,大多以延性、承载力、滞回耗能等特征为参考,很少考虑累积损伤的影响,损伤模型在实际地震作用下损伤评估的应用研究少之又少。由于地震的随机性,不同地震作用下结构的反应差别较大。为此,本文对钢管混凝土柱进行了不同地震动强度下的动力时程分析,并从概率的角度对钢管混凝土柱的地震损伤进行了较为系统的研究。采用Perform-3D软件,选取18条强震记录,对某钢管混凝土桥墩实例进行了增量动力分析,详细分析了墩柱在不同地震作用下的位移反应、弯矩-曲率关系及耗能等特性。研究表明,钢管混凝土柱能够抵抗较强的地震作用,具有良好的抗震性能。对比分析了不同累积损伤模型,提出了基于损伤指标的地震累积损伤评估方法,并对钢管混凝土柱进行了易损性分析。结果表明,对于设防烈度为7度的钢管混凝土墩柱,在7度E1地震作用下处于基本完好状态,在7度E2地震作用下发生严重破坏和失效的概率为0,在两种超罕遇地震作用下失效的概率较小,满足抗震设防目标。研究结果可为钢管混凝土柱基于性能的抗震设计和震后修复提供参考。通过对7个不同参数模型的分析考察了长细比、径厚比和轴压比对钢管混凝土柱地震反应和累积损伤的影响。结果表明,3个参数对钢管混凝土柱抗震性能和累积损伤的影响较为显著,各个参数对钢管混凝土柱的影响规律不同。更多还原

【Abstract】 Earthquake is an unpredictable natural disaster, which will cause damage in different degrees to structure, and endanger people’s lives and property safety seriously. The action of earthquake is a cyclical process. Even if the structure does not have a great response throughout the process, but the cumulative damage under reciprocating action may cause structural damage. Concrete filled steel tubular(CFT) columns have been widely used in high rise buildings, industrial buildings and bridge structures because of their many advantages. At present, most of the seismic performance evaluations of CFT columns are based on the characteristics of ductility, bearing capacity, hysteretic energy dissipation and so on, and effects of cumulative damage are seldom considered. There is little research on the application of damage model in the actual earthquake damage assessment. The response of structure under different earthquake action is different because of the randomness of earthquake. In this paper, the dynamic time history analysis of CFT columns under different ground motion intensity is carried out, and the seismic damage of CFT columns is studied systematically from the angle of probability.An incremental dynamic analysis of a CFT bridge pier example under 18 strong ground motion records was carried out by Perform-3D, and the characteristics of displacement response, moment-curvature relationship and energy dissipation of the column under different earthquake were analyzed in detail. The results show that the CFT column can resist strong earthquake, and has good seismic performance.Different damage models were compared and analyzed, and a seismic damage assessment method based on damage index was put forward, the vulnerability analysis of CFT column was carried out at the same time. The results show that for the CFT pier with a fortification intensity of 7, the pier is in perfect condition under 7-degree E1 earthquake action,and the probability of serious damage and failure is zero under 7-degree E2 earthquake action, and the probability of failure under two ultra rare earthquakes is small, which indicate that the bridge pier can satisfy the target of seismic fortification. The research can provide reference for the performance-based seismic design and post-earthquake restoration of CFT columns.Through the analysis of 7 different models, the effects of the length to thickness ratio, diameter to thickness ratio and axial compression ratio on the seismic response and cumulative damage of CFT columns were investigated. The results show that the influences of the 3 parameters on the seismic behavior and cumulative damage of CFT columns are significant, and different parameters have different effects.更多还原