基于长标距光纤传感的桥梁区域监测方法及车辆时空信息识别理论研究

Vehicle overloading is one of the main causes for frequent traffic accidents and severe damage to bridge infrastructure, so it is urgent to effectively early warn and monitor the overloaded vehicles on bridge in real time. Taking the 2-D bridge model as the research object, the long-gauge fiber bragg grating (FBG) sensing technology is used in this project to provide an effective way for the breakthrough of load identification theory research in the field of bridge monitoring combing with the signal processing technology, because it reflect the macro and micro information of the structure and can be connected into a network. The research content includes two aspects. The first one is to divide bridge elements into monitoring elements, prediction elements and remaining elements and then to explore the complex mapping relationship between the response of monitoring element and prediction element. In such a case, an area monitoring method can be established for the comprehensive estimation of bridge response. With the real bridge calibration test, the other aspect is to develop the spatio-temporal information identification theory of vehicles through analyzing the relevant information in the corresponding response of different lanes caused by the same axle load. This project is expected to locate and track overloaded vehicles on the bridge, which can provide a strong guarantee for effective early warning of overloaded vehicles. The research results also have important practical significance and application value for the design and evaluation of bridge structure.

车辆超载是交通事故频发、桥梁基础设施严重破坏的主要原因之一，有效预警并实时监测桥梁上超载车辆的研究工作迫在眉睫。本项目以二维桥梁模型为研究对象，利用长标距光纤光栅（FBG）传感技术反映结构宏微观信息和连接成网的特点，结合信号处理技术，为荷载识别理论研究在桥梁监测方面的突破提供有效途径。本项目侧重于以下内容研究：一、它通过将桥梁单元分为监测单元、预测单元及剩余单元三类，探索监测单元与预测单元响应间的复杂映射关系，建立桥梁响应全面估计的区域监测方法；二，它分析不同车道对应响应中包含的相同车轴荷载作用效应的关联信息，结合实桥校准测试，开发桥梁车辆时空信息识别理论。本项目预期将在桥梁上实现定位、跟踪超载车辆，这可为有效预警超载车辆提供有力保障。项目研究成果对桥梁结构的设计与评估也具有重要的实际意义和应用价值。

车辆超载是交通事故频发，桥梁基础实施严重破坏的主要原因之一，有效预警并实时监测桥梁上超载车辆的研究工作迫在眉睫。本项目以二维桥梁模型为研究对象，利用长标距光纤光栅传感技术和信号处理技术，为荷载识别理论研究在桥梁监测方面的突破提供有效途径。在较少传感器数目的前提下，本项目首先基于本征正交分解（POD）原理建立了桥梁区域监测的方法。该方法将未监测单元分为两层次进行响应重构，通过建立单元间本征模态的复杂映射关系来对单元的本征模态进行修正，从而获取有效的单元响应。其次，桥梁上车辆时空信息的识别主要是确定车轴的空间分布和车辆荷载的识别。为了解决这两个难题，本项目通过分析截面横向应变与作用车轴之间的关系，结合数据分离技术，确定车轴的时空分布信息；进而分析车轴信息对结构响应的影响，利用校准测试获取了桥梁的应变影响线；依据建立的影响面和反问题识别原理确定目标函数，最终建立多车道多车辆的荷载信息识别理论。通过有限元仿真和实验室试验缩尺模型对本项目所提方法的有效性和鲁棒性进行了验证，结果表明：所提出的识别理论在多车运行下的轴重和车辆总重识别误差均能满足工程需要，说明该方法能够可靠地识别车辆荷载的时空信息，为有效预警超载车辆提供有力保障。