【作者】 黄虎；

【导师】 张社荣；

【作者基本信息】 天津大学 ， 水工结构工程， 2010， 博士

【摘要】 进水口是水电站的重要组成部分,其安全性直接影响到水电站运行和发电效益。在运行期间,塔式进水口结构大部分位于水下,且多为高耸、单薄的箱式或筒式结构。地震发生时,结构和水体之间的相互作用;进水塔在地震作用的裂缝状态;高坝大库的进水塔群塔体之间的相互作用;作用于闸门的脉动压力;闸门的流激振动等都是值得关注的问题。本文对进水塔和水体的相互作用、进水塔在地震作用下裂缝的出现和发展方式、整体进水塔群塔段间的相互作用、叠梁闸门的脉动压力及闸门振动问题进行了系统的研究。研究成果对大型水电站进水塔结构优化设计和稳定运行具有重要的参考价值。主要成果如下:采用流固耦合理论研究塔体结构自振特性和地震作用下的动力响应,分析塔体与水体的相互耦合作用。对于水下高耸进水塔结构,水体与其流固耦合作用明显,采用强流固耦合方法比常规方法更能表现流体和固体的相互作用;并给出流固耦合作用下进水塔体表面的动水压力分布特征。根据当前有限元的计算特点,提出混凝土结构的破坏判断方法;在此基础上对分层取水进水塔结构进行地震荷载作用下塔体裂缝开展方式和破坏模式的研究,得出进水塔在地震过程中的破坏规律。对于大跨度的进水塔群而言,考虑地震的行波效应对结构响应存在一定的影响,尤其对于塔段之间的相互作用影响较大。根据计算结果,各塔段间发生较明显的挤压碰撞现象;塔段间的相互作用受地震波速影响较大。采用Matlab自编S-变换程序对脉动压力信号进行时频转换分析,根据时域和频域的相互关系说明了水脉动压力的振幅和相位的分布特征;通过闸门自振特性和脉动压力的优势频率和能量分布特点,对闸门和脉动压力共同存在条件下出现共振的可能性做出了相应评价。采用有限元方法进行数值仿真分析。根据水弹性模型试验结果,利用随机振动功率谱法进行闸门结构的流激振动分析,求解闸门在水脉动压强下的随机动力响应,评价叠梁闸门在流激荷载作用下的响应特征。更多还原

【Abstract】 The intake is an important part of the hydroelectric station, which safety is link to the normal working and the hydroelectric station benefit. The intake tower as a tall thin trunk or a columnar is in the water under normal working. There are some questions must be regarded when seism happens, for example, the interaction between structure and water,the crack form,the interaction between intakes,the pulsating water pressure and the flow-induced vibration of the stop log gate. This paper had done lots of systemic work according to the mentioned questions above. The research is important to the structure optimize design and the normal working for high intake tower of big hydroelectric station, the main parts of which are listed as below.The theory of fluid-structure interaction was applied to the research about the self vibration characteristic, the response of the structure and the interaction between structure and water. The interaction is more distinct by the strong fluid-structure interaction, and the dynamical pressure was showed as figure in the paper.This paper brought forward a judgment of the concrete’s breakage according to the characteristic of the finite element, which was applied to the research of the intake tower under earthquake, the rule of breakage for the intake tower was showed in the paper.The effect of traveling wave is important to the long span intake tower group, especially for the interaction between towers. As the results show: the collision between the towers was obvious and the interaction was effected obviously by the seismic waves.A s-transform program based on Matlab was used to the time-frequency transform analysis on pulsating water pressure, explained the distributing characteristic of the swing and the phase of pulsating water pressure; and then make an estimate of resonance between the strobe and the pulsating water pressure according to the self vibration of strobe and the dominant frequency of pulsating water pressure.According to the model test result and the finite element method, a random vibration power spectrum was utilized in this paper to study the flow-induced vibration of the strobe, the response of the strobe under the pulsating water pressure was achieved, finally, an estimate was made for strobe.更多还原