基于磁性标签石块的桥墩局部冲刷监测方法

针对桥墩局部冲刷监测存在服役环境恶劣、传感器需粗放式布设等特点,提出基于磁性标签石块的桥墩局部冲刷监测方法。桥墩局部冲刷监测系统,包括磁性标签石块和磁力梯度仪。磁性标签石块采用磁性标签浇筑成混凝土石块,通过运动自由度缩减的方式,避免了基于优化搜索的磁场梯度反演中的非线性和不适定性的问题,采用磁场梯度反演磁性标签石块的三维运动,实现桥墩局部冲刷的动态监测。在磁性标签石块的模拟定位试验中,最大误差为0.2m,最大相对误差为5%,满足桥墩局部冲刷监测的要求。磁场梯度、磁场梯度张量不变量及张量的模量均与冲刷位移场高度相关,可直接用于冲刷监测的早期预警。

Bridge local scour monitoring using magnetic label rock

The bridge local scour monitoring is characterized by adverse environment with great danger which makes sensor arrangement very difficult. So, we proposed using magnetic label rock as a dynamic scour sensor for bridge scour monitoring. The monitoring system consists of magnetic label rock and magnetic gradiometer. The magnetic label is casted into concrete to construct a magnetic label rock. The degree of freedom is reduced to solve the nonlinear and ill-posed problems in the magnetic reversion by means of optimization search. In the experimental verification for localization of magnetic label rock, the maximum error and relative error for localization is about 0.2 m and 5% respectively, which satisfies the requirement in the bridge local scour monitoring. The magnetic gradient, invariants and magnitude are all highly correlated with scour displacement, which can be directly used for early warning in the bridge local scour monitoring.