基于DBHM的服役中小跨径桥梁快速检测理论及应用研究

针对我国中小跨径桥梁老化严重、病害频现、整体运营堪忧的现状，本项目基于DBHM（Drive-By Bridge Health Monitoring）技术，利用行驶过桥车辆响应信号间接获取桥梁动力参数信息，从而对服役中小跨径桥梁进行快速检测及运营状态评估。研究内容包括：1）DBHM中桥梁振动‘弱信号’高效识别和提取；2）DBHM中复杂车辆和桥梁模型的耦合力学性能研究；3）DBHM中车载传感元件类型与最优安装位置研究；4）DBHM中路面粗糙度的影响分析及适用于DBHM的‘短数据流’算法研究；5）提取目标桥梁健康状况下的特征值分布空间并提出基于DBHM技术的桥梁损伤识别模型。本项目将提出一套基于DBHM技术的桥梁快速检测理论和安全评估方法，初步实现该技术在中小跨径桥梁检测中的工程应用，提高当前服役中小跨径桥梁的检测效率，这对改善其运营状况并延长其服役寿命有广泛的理论与实用价值。

There are over 800,000 bridges in China, and about 90% of that are small and medium-spans. Because of the issue of "aging", overloads, most of small and medium span bridges are functionally deficient, leading to frequent accidents on that. Nowadays, manual inspection combined with dynamic and static load tests are still the most common and effective method for periodic monitoring of existing bridges. However, this method of bridge inspection is uneconomic, inefficient, time-consuming and even dangerous. In regard to over 600,000 bridges of small and medium-spans, this conventional method of bridge inspection is unable to meet the demand for its maintenance and safe operation. This project proposes to use the signals of passing vehicle over the bridge to indirectly obtain the bridge parameters, based on the effect of vehicle-bridge interaction. The indirectly obtained bridge parameters are then applied to calculate the bridge related damage index, so as to implement the fast inspection of the bridge and to evaluate its operation safety. To facilitate the application of DBHM (Drive-By Bridge Health Monitoring) on small and medium span bridges, the following aspects will be carried out: (1) To investigate the high-efficiency identification and extraction of the 'weak signals' related to bridge vibration component from vehicle signals; (2) To study the coupling mechanical properties of complex vehicle and bridge models; (3) To analyze different vehicle-mounted sensing types and to identify the most effective installation locations; (4) To investigate the influence of road surface roughness in DBHM and to propose modified DBHM algorithms related to ‘short data burst’; (5) To establish the bridge damage recognition model for the further inspection and evaluation of existing bridges based on the proposed DBHM algorithms. The research in the project will contribute to improve and extend the accuracy and applicability of existing algorithms of DBHM and overgo the gap between the current theoretical research and practical application of the DBHM system, which considerably improves the efficiency of small and medium span bridges’ inspection, consequently ameliorating their operating conditions and extending their service life.