156m水位下三峡水电站15#机组厂房结构的振动安全研究

Study on vibration safety of powerhouse under water level of 156 m for 15th unit of Three Gorges Hydropower Plant

三峡水电站机组蜗壳HD值高,其埋设方式对厂房和机组的安全稳定运行具有关键的影响。蜗壳直接埋入法相对于垫层埋入法和充水保压埋入法而言,其外围钢筋混凝土承担的内水压力较大,但施工比较简单且节省蜗壳钢材,因此三峡水电站15#机组拟采用直接埋入法。文中在已有静力研究成果的基础上,分析了局部混凝土开裂后的厂房结构的整体自振特性和振动响应,并根据计算结果和振动标准对厂房结构的振动做了安全评价。

On account of the high value of HD for the spiral cases of turbine-generating units in Three Gorge Hydmpower Plant, the embedding method for the case has a significant effect on safe and stable operation of both the powerhouse and the units. Compared with the embedment with cushion and the embedment with the method of water-filling and pressure-maintaining, a greater internal water pressure has to be born by its surrounding reinforced concrete, if the direct embedment is applied to the embedding of the spiral case of the unit, however, the construction can be simplified and the steel for the case can be saved to a certain extent with this method. Therefore, the direct embedment is planned to be applied to the spiral case for the 15th turbine-generating unit. Based on the existed analysis concerned, the self-oscillation characteristics of the integral powerhouse with local cracks on the concrete and its vibration response are analyzed herein, and then a safety assessment is made on the vibration of the powerhouse structure in accordance with the relevant calculation and vibration control standards.