Scour is the removal of ground material in water bodies due to environmental changes in water flow. It particularly occurs at bridge piers and the holes formed can make bridges susceptible to collapse. The most common cause of bridge collapse is due to scour occurring during flooding, some failures causing loss of life and most resulting in significant transport disruption and economic loss. Consequently, failure of bridges due to scour is of great concern to bridge asset owners, and is currently very difficult to predict since conventional assessment methods foresee very resource-demanding monitoring efforts in situ. This paper presents evidence of how InSAR techniques can be used to monitor bridges at risk of scour, using Tadcaster Bridge, England, as a case study. Tadcaster Bridge suffered a partial collapse due to river scour on the evening of December 29th, 2015 following a period of severe rainfall and flooding. 48 TerraSAR-X scenes over the bridge from the two-year period prior to the collapse are analysed using the small baseline subset (SBAS) interferometric synthetic aperture radar (InSAR) approach. The study highlights a distinct movement in the region of the bridge where the collapse occurred prior to the actual event. This precursor to failure observed in the data over a month before actual collapse suggests the possible use of InSAR as a means of an early warning system in structural health monitoring of bridges at risk of scour.

冲刷是由于水流环境变化而去除水体中的地面物质。它尤其发生在桥墩处，形成的孔会使桥容易倒塌。桥梁倒塌的最常见原因是洪水期间发生的冲刷，某些破坏导致人员伤亡，并且大多数导致严重的运输中断和经济损失。因此，由于冲刷而导致的桥梁故障是桥梁资产所有者非常关心的问题，并且由于传统的评估方法预见到非常耗资源的监测工作，因此目前很难预测。本文以英国Tadcaster桥为例，提供了有关InSAR技术如何用于监视有冲刷危险的桥梁的证据。在经历了一段时间的强降雨和洪水之后，Tadcaster桥在2015年12月29日晚上由于河水冲刷而部分塌陷。使用小型基线子集（SBAS）干涉合成孔径雷达（InSAR）方法分析了倒塌之前两年内桥梁上的48个TerraSAR-X场景。这项研究突出了在实际事件发生之前坍塌发生的桥梁区域的明显运动。在实际倒塌之前一个月内，在数据中观察到的这种破坏的先兆表明，可能将InSAR用作预警系统的手段，用于对有冲刷危险的桥梁进行结构健康监测。