本文介绍某大型升船机塔柱结构这一门式连体结构1/25缩比结构模型的振动台试验研究结果。试验中考虑了不同加速度记录、单向或多向同时激励等不同激励方式、加速度峰值以及船厢不同工作位置等因素的影响。试验结果表面,由于塔柱结构对称性强,塔柱结构的响应以单向响应为主,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合成;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,此特征不受输入方式及输入地震动不同的影响;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。
This paper summarizes the shaking table test results of a 1/25 scaled structural model of a large triumphal arch type twin-tower ship lift tower, with movable ship-chamber model and balance chain systems included. Dynamic characteristics and dynamic responses of the structural model under different base acceleration excitations with different peak acceleration levels, different base excitation methods (such as one-way, two-way or three-way excitation) and different ship-chamber positions were measured. The test results reveal that the dynamic response of the model under one-way excitation is the governing component. Its dynamic response under multi-way excitation could be predicted on the basis of 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 smaller 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 is at the different positions, however, the maximum coupling forces between the ship-chamber and the tower change significantly for the ship-chamber model at 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.