华南地震

地震作为一种破坏性极强的自然灾害，往往会给桥梁结构带来严重的影响，例如位移、倾斜等变形，因此为了及时有效地监测和评估桥梁的响应情况，确保桥梁正常运行和人员的安全，提出地震作用下的桥梁位移响应倾斜摄影监测方法。通过最佳桥梁挠度曲线确定位移变化最显著或最具代表性的区域，将该区域作为倾斜摄影监测点位置。采用无人机搭载摄像机的方式采集地震作用下监测点位置桥梁倾斜图像，通过Harris算子提取图像亚像素角点并进行特征描述子生成，结合亚像素模版匹配方法进行在地震作用下的桥梁亚像素级位移跟踪。引入比例因子对桥梁位移响应亚像素级位移数值进行转换，得到准确的地震作用下桥梁位移响应数值，对每幅倾斜摄影图像的桥梁位移响应数值进行融合后得到桥梁位移响应倾斜摄影监测结果。实验结果表明，该方法具备较为准确的亚像素角点提取能力，计算的地震作用下桥梁亚像素级位移响应数值与实际值较为吻合，可有效实现地震作用下桥梁位移响应监测，应用效果较为显著。

As highly destructive natural disasters， Earthquakes often have serious impacts on bridge structures， such as displacements， tilt， and other deformations. An oblique photography monitoring method for bridge displacement response under earthquake action was proposed to monitor and evaluate the response of bridges in a timely and effective manner and to ensure the normal operation of bridges and the safety of personnel. Determining the areas with the most significant or representative displacement change through the optimal bridge deflection curve， and these areas were used as the location of the oblique photography monitoring points. Using drones equipped with cameras， oblique images of the bridge at the monitoring points under earthquake action were collected. The sub-pixel corner points of the images were extracetd by the Harris operator， and the feature descriptors were generated. The sub-pixel template matching method was combined for bridge sub-pixel displacement tracking under earthquake action. By introducing a scaling factor，the sub-pixel displacement values of the bridge displacement response were converted to obtain accurate values of bridge displacement response under earthquake action. The displacement response values from each oblique photography image were then integrated to produce the final monitoring results. The experimental results show that this method has a relatively accurate capability for extracting sub-pixel corner points. The calculated sub-pixel displacement response values of bridges match well with the actual values. The method can effectively realize the monitoring of bridge displacement response under earthquake，with significant application effectiveness.