基于光纤光栅技术的冲淤深度测量方法

Sediment depth measurement method based on the technology of fiber Bragg grating

由于冲刷和淤积引起的结构物和航运安全问题,水下泥面的冲淤监测已经成为结构健康监测中的一项重要的任务。本文对基于侧向土压力测量确定水下冲淤深度的方法进行可行性研究。该方法利用以光纤光栅作为传感元件的传感器,正面承受水土压力,背面承受水压力,通过测量正面和背面的压力差可以精确测量侧向土压力;由于水体中水平方向压力只有水压力,土体中水平方向压力由侧向土压力和孔隙水压力组成,因此通过若干只不同深度位置的传感器,计算出冲淤深度。该方法能实现水工结构的冲淤情况实时反馈,为水工结构安全运行提供可靠的数据支持。

The hydraulic structures and shipping safety is threatened by washing and deposition. The monitoring of the underwater deposit clay is important to the structure health. The feasibility study on the deposition depth measuring method based on earth pressure monitoring is performed. The method use fiber Bragg grating sensor to monitor the front side pressure and the back side pressure. The front side bears water and soil pressure,and the back side bears water pressure. The lateral earth pressure is then derived precisely by measuring the difference between front and back side. Only water pressure exists at horizontal direction in the water,while a combination of lateral earth pressure and pore water pressure exists in deposit soil. The deposit depth could be calculated based on the monitoring data of several sensors at different depth. This method could acquire the deposit in a real-time way and provide a support for the safe operation of the hydraulic structure.