【作者】 管桦；

【导师】 赵作周；

【作者基本信息】 清华大学 ， 土木工程， 2009， 硕士

【摘要】 本文以某大型升船机结构为背景,介绍了该门式连体塔柱结构1:25缩尺模型的模拟地震振动台试验情况。基于该结构模型的实测动力响应,分析了该结构的抗震性能。另外,用有限元程序SAP2000对该模型进行弹性时程计算。试验和计算结果表明,由于此升船机塔柱结构对称性强,塔柱结构的响应以单向的响应为主,双向或三向同时激励下塔柱结构的响应可由单向激励下的响应组合而成;沿塔柱高度其纵横向的最大加速度响应包络图呈S形分布,在10层附近塔柱的加速度响应较小,此特征不受模拟地震输入方式与输入地震波不同的影响;随着激励水平的提高与模型损伤的积累,塔柱水平加速度动力放大系数沿高度趋于均匀;船厢处于不同工作位置对塔柱结构的动力响应影响很小,但对船厢和塔柱结构间耦合力的影响显著,船厢处于最高位时耦合力最大。基于试验结果,得出现有设计结果可以保证该升船机塔柱结构在设计地震下的安全并有足够的安全储备。针对该升船机塔柱纵立面开洞少、沿高度塔拄筒体内楼板少,摆放附加配重的困难,提出了局部增加楼板或减少楼板以及外纵墙临时开洞口的解决方法,并利用SAP2000软件对简化试验模型进行了计算分析,计算结果表明简化方法是可行的,但是外纵墙预留洞口必须修补,才能更好模拟原型的动力特性。最后,本文对我国目前振动台模型试验采用的相似关系进行探讨。采用有限元软件SAP2000和MARC,预测了按照一致相似律设计的一座六层框架欠人工质量模型在不同配筋率下不同配重因素的影响。发现配筋率较小时配重不足的影响明显,配筋率较大时影响不明显。对模型钢筋采用与原型钢筋接近而模型混凝土弹模相似比采用0.3、按照一致相似律设计且不同配重的一座六层框架欠人工质量模型分析结果显示,按照等面积配筋率设计的模型将高估原型结构的抗震能力,按照构件承载力相似原则设计的模型能较好反映原型结构的地震响应。更多还原

【Abstract】 This thesis presents the shaking table test results of a 1/25 scaled structural model of a large ship lift tower, a large triumphal arch type twin-tower skyscraper. Based on the measured dynamic responses of the structural model, seismic performance of the structure was evaluated. Furthermore, linear time-history analysis of the structural model was carried out by using program SAP2000.Both the test results and analytical results reveal that the dynamic response of the model under one-way excitation is the governing component. Its dynamic response under multi-way excitation can be predicted based on its one-way excitation results because the tower structure is symmetric. The peak acceleration envelopes of the model along the model height are S-shaped with the smallest peak acceleration near the 10th floor level. This characteristic does not change with different earthquake records or different base excitation methods. The variation of the acceleration amplification factor along the model height becomes uniform with base peak acceleration increased. The dynamic response of the tower does not change obviously when the ship-chamber model was in different positions, however, the maximum coupling forces between the ship-chamber and the tower changed significantly for the ship-chamber model in different positions. Based on the experimental results, it can be concluded that the designed ship lift tower is safe under the design earthquake level and has sufficient safe margin.Due to few holes on the longtitudinal surface of the ship lift tower and few floors in the ship lift tower along its height, placing additional mass on the available floors is difficult. In order to solve this problem, adding or eliminating the floor plates at some local levels and leaving temporary opens on the longtitudinal surfaces of the tower model were adopted. SAP2000 software was used to predict the possible effects of the former variations. The predict results demonstrate that the propoded method is feasible. However, the temporary opens on the longtitudinal surfaces must be carefully piece up.Finally,some discussions on the similitude laws adopted in shaking table test in China’s mainland during the last decades were summarized. Pushover analysis and nonlinear dynamical analysis of different structural models of a 6-story frame structure were carried out by using software SAP2000 and MSC.MARC respectively. Variables considered are column reinforcement ratios and lack artificial mass degree. It was found that the effect of the lack artificial mass degree is significant for the model with smaller column reinforcement ratio and will be acceptable for the model with larger column reinforcement ratios. If the mechanical parameters of the model reinforcement is close to those of the prototype reinforcement but the Young’s modulas ratio of the theoretical concrete model is 0.3 for a scaled 6-story frame structural model with lack additional mass, the seismic resisting capacity of the prototype structure will be overestimated based on the results of the scaled model. However, if the structural elements are designed based on similitude capacity principle, the predicted seismic behavior of the prototype structure will be more reliable.更多还原