基于光纤光栅的高陡边坡及危岩落石监测技术与应用研究

发布时间：2018-06-13 07:45

本文选题：边坡工程 + 危岩落石防护　；参考：《武汉理工大学》2014年博士论文

【摘要】：边坡工程是交通设施建设中常见的土木工程形式，高陡边坡的失稳和崩塌落石等地质灾害严重威胁着交通运输安全。随着我国高速公路、高速铁路的快速发展，高陡边坡的安全问题越来越突出，开展高陡边坡的在线安全监测与预警迫在眉睫。目前边坡安全监测大都采用传统的电磁类传感和仪器，这类设备不具备在线监测以及抗自然界电磁干扰等能力。而基于光纤光栅技术的传感器具备电磁类传感无法比拟的技术优势：其光信号可远距离传输、具有抗雷击等电磁袭扰、可串接复用等，这些优势特别适用于野外恶劣环境下的工程健康监测。本文在中国铁路总公司（原国家铁道部）和中铁二院工程集团、国家自然科学基金委等重大基金的支持下，以高陡边坡和危岩落石为研究对象，重点研究其安全运营中重要、关键物理量的光纤光栅传感安全监测新原理、新方法和新技术，注重理论设计与工程实际应用紧密结合，将提出的监测新原理和方法以及研制的光纤光栅传感器应用于实际边坡工程现场和落石冲击试验现场。在边坡安全监测方面，通过建立边坡模型并开展离心加速变形试验，研究了边坡的变形失稳特征和机理，在此理论研究基础上，针对边坡内部变形的特殊需求，提出了一种通过监测埋入到坡体内部的柔性杆的变形反演出边坡内部变形特征的测量方法，对该方法进行了传感器模型的试验验证。针对传统的光纤光栅锚杆测力方法存在的操作不便且无法标定等缺陷，研制了一种新型光纤光栅锚杆测力计；根据边坡表面位移监测要求，研制并开发出一种斜面结构的光纤光栅位移传感器，并通过工程实际验证了这些传感器及仪表的有效性。采用ANSYS显式动力学分析了防护网受落石冲击过程，研究了危岩落石防护网的受力变形特征和光纤光栅传感测量方法与实施技术。根据数值分析结果，提出了一种温度自补偿的拉力传感转换弹性结构体。在理论分析的基础上，基于该弹性体制造了两种量程的光纤光栅拉力传感器。此外，根据防护网振动冲击监测要求，，研制了一种增敏结构的光纤光栅振动传感器，以及一种全金属封装的光纤光栅振动传感器，并在工程现场应用。研究过程中，将理论设计与工程实际应用紧密结合，对吊水岩边坡的内部变形长期在线监测进行了研究，引入了一种变形数据处理与分析方法。通过对吊水岩边坡两个光纤光栅变形监测点几个月的数据利用该方法处理，得出该吊水沿边坡处于非稳定的加速变形状态。将光纤光栅位移传感器应用于吊水岩大桥的伸缩缝位移监测，传感器长期工作性能稳定，监测结果与实际情况一致。同时，开展了贵广铁路某边坡的锚杆应力长期监测，获得了锚杆不同长度处的应力变化情况。同时验证了研究工作的可靠和有效性。将光纤光栅拉力传感器、振动传感器以及应变光栅应用于落石冲击试验中，有效的获得了整个试验过程中钢丝绳拉力和钢柱应变的动态响应过程监测数据，监测结果与防护网的动力学有限元分析结果吻合。此外，根据防护网的冲击数值模拟和两次现场试验结果，提出了五种落石冲击判别响应模式，对落石冲击判别监测具有重要的实际意义。
[Abstract]:Slope engineering is a common civil engineering form in the construction of traffic facilities. The geological disasters such as instability of high steep slope and rockfall and rockfall threaten the safety of traffic and transportation seriously. With the rapid development of highway and high-speed railway in China, the safety problems of high and steep slopes are becoming more and more prominent, and the online safety monitoring and early warning of high and steep slopes is forced to be carried out. At present, most of slope safety monitoring uses traditional electromagnetic sensors and instruments. This kind of equipment does not have the ability of on-line monitoring and resistance to natural electromagnetic interference. And the sensor based on Fiber Bragg grating technology has the advantages that electromagnetic sensing can not compare: its optical signal can be transmitted in a long distance, and it has anti lightning strike and other electromagnetic attacks. These advantages are especially suitable for engineering health monitoring in harsh environment.
With the support of major funds such as China Railway General Corporation (former national railway ministry), the second Institute of China Railway and the National Natural Science Foundation of China and the National Natural Science Foundation of China, high steep slope and rockfall are taken as the research object. The new principle, new method and new technology of optical fiber optic grating sensing, which are important and key physical quantities in safety operation, are emphatically studied. The heavy theoretical design is closely combined with the practical application of the engineering. The new monitoring principles and methods proposed and the developed fiber grating sensors are applied to the actual site of the slope engineering and the site of the rockfall impact test.
In the side slope safety monitoring, by establishing the slope model and carrying out the centrifuge acceleration deformation test, the deformation instability characteristics and mechanism of the slope are studied. On the basis of this theory, a kind of deformation of the flexible bar which monitors the deformation of the slope inside the side of the slope is put forward in view of the special requirement of the internal deformation of the slope. A new type of fiber Bragg grating bolt dynamometer has been developed to develop and develop a kind of optical fiber light of the slope structure according to the requirement of the surface displacement monitoring of the slope. The grid displacement sensor is verified by engineering practice and the effectiveness of these sensors and instruments is verified.
The ANSYS dynamic analysis is used to analyze the impact process of the rockfall on the protective net. The characteristics of the stress and deformation of the rockfall protection network and the sensing method and the implementation technology of the fiber Bragg grating are studied. Based on the results of the numerical analysis, a self compensated tension sensing transfer elastic structure is proposed. Based on the theoretical analysis, the projectile is based on the theory analysis. Two kinds of fiber Bragg grating tension sensors are manufactured by the sex body. In addition, a fiber Bragg grating vibration sensor with an sensitized structure is developed and a kind of all metal package fiber grating vibration sensor is developed and applied to the engineering site.
In the course of the study, the theory design and the practical application of the engineering are closely combined. The long-term on-line monitoring of the internal deformation of the suspended rock slope is studied. A deformation data processing and analysis method is introduced. By using this method to deal with the two fiber Bragg grating deformation monitoring points of the hanging water rock slope for several months, the boundary of the hanging water side is obtained. The fiber Bragg grating displacement sensor is applied to the displacement monitoring of the expansion joint of the suspension bridge. The long-term performance of the sensor is stable and the monitoring results are consistent with the actual conditions. At the same time, the long-term monitoring of the anchor stress of a slope in the Guiyang Guangzhou railway is carried out, and the stress changes at different lengths of the bolt are obtained. At the same time, it verifies the reliability and effectiveness of the research work.
The fiber grating tension sensor, the vibration sensor and the strain grating are applied to the rockfall impact test. The monitoring data of the dynamic response of the wire rope tension and the steel column strain during the whole test process are effectively obtained. The monitoring results are in agreement with the dynamic finite element analysis results of the protective net. In addition, the impact values of the protective net are calculated. Based on the results of simulation and two field tests, five kinds of rockfall impact discrimination models are proposed, which are of great practical significance for discriminating and monitoring rockfall impact.
【学位授予单位】：武汉理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P642.2;TU196

【参考文献】