混凝土成层结构的流激振动特性

泄流激励引起水工建筑物振动的现象时有发生且形式多样,严重的还可能引起结构的破坏。对于混凝土成层结构而言,由振动引起破坏的案例不多,对其振动响应机制的研究也不够深入。以混凝土拱坝为例,通过数值计算及模型试验对比分析了整体与成层两种不同结构在相同泄流荷载作用下结构的振动响应,探讨了响应与结构自身的关系,并结合"拍"的概念,对混凝土成层结构振动响应特性与泄流荷载之间的关系进行了研究。结果表明,成层结构频率相近的前两阶振动是拍振形成的主要原因。此外,即使不满足拍振形成的条件,振动曲线同样可以表现为"拍"的形式,且振动量较受迫振动大幅增加,实质为"水力共振"现象。

Research on flow 2induced vibration characteristics of layered concrete structure

Vibration of hydraulic structures caused by flood discharge excitation occurs frequently and has different forms, andserious vibration may lead to structural damage. Few cases of damage caused by vibration for layered concrete structures werepresented, and the study of vibration response mechanism was not enough. In this paper, the vibration responses of concrete archdam with two different structures, including a whole structure and a layered structure, under the same flow discharge conditionswere investigated through the comparative analysis of numerical calculation and model test. The relationship between the struc 2ture and vibration response was analyzed. Furthermore, the relationship between the vibration response of layered concretestructure and flow discharge was studied in consideration of the "beat" concept. The results showed that the beat vibration ismainly caused by the first two bands of vibration with similar frequency. Although the conditions for the formation of beat vi 2bration may not exist, the vibration curve can present the form of "beat", and the vibration quantity is much large than that ofthe forced vibration, which indicated that this is actually the hydraulic resonance phenomenon.