闸阀失效诱发水库输水涵管振动探测与分析

Detection and analysis of vibration induced by the gate valve failure of a reservoir water conveyance culvert

为了对某水库输水涵管振动原因进行分析,首先采用振动监测仪对管道不同位置振动特性进行监测,分析管道不同位置振动变化规律,初步确定了振源位置;其次通过管道机器人对管道内部进行探测,结合已有理论基础初步分析了管道振动的内因;最后通过现场开挖,分析了管道振动的外因。结果表明:闸阀位置处质点振动峰值速度、主频、峰值加速度和峰值位移均明显大于其他测点,闸阀前后振动特性基本对称,推测闸阀为主要的振动源;闸阀处各方向质点振动峰值速度、峰值加速度和峰值位移均为垂向>切向>径向,推测闸阀的主要振动方向为垂向;输水涵管闸阀仅能开启至设计最大开度的1/3位置处,当闸阀在此种小开度开启时,产生的垂向流激振动是输水涵管振动的主要原因;闸阀附近土体松散,且未设置镇墩,无法较好地约束输水涵管变形,从而导致振动加剧。

To analyze the vibration causes of a reservoir water conveyance culvert,the vibration characteristics of different positions of the culvert were monitored using a vibration monitor,and the source location of the vibration was preliminarily determined by analyzing the vibration variation law of different positions of the culvert. Then,a pipeline robot was used to examine the inside of the culvert,and the internal cause of the pipeline vibration was then analyzed based on the existing theory. Finally,the external causes of pipeline vibration were analyzed after the field excavation. The results show that the peak velocity,dominant frequency,peak acceleration and peak displacement of the particle at the position of gate valve are significantly greater than those at other measuring points. The vibration characteristics in front of and behind the gate valve are basically symmetrical,so it is speculated that the gate valve is the main vibration source. The vibration peak velocity,peak acceleration and peak displacement of the particle at the gate valve are vertical > tangential > radial,and the main vibration direction of the gate valve is vertical. The gate valve of water conveyance culvert can only be opened to no more than 1/3 of the designed maximum opening. When the gate valve opens at such a small opening,the vertical flow induced vibration is the main reason causing the vibration of the water conveyance culvert. The soil mass near the gate valve is loose,and there is no anchorage block to restrain the deformation of the culvert pipe,resulting in the vibration aggravation.