光纤光栅传感器在道路土基监测中的应用

发布时间：2018-11-27 18:50

【摘要】：近年来我国的公路运输事业取得了巨大的发展,随着高速公路的大规模建设,软土地基处理的问题显得越来越重要。虽然软土地基的加固手段日益完善,可以使其沉降并达到足够坚固,但是其长期稳定性也是一个重要的问题。软土地基如果处理不当或后期稳定性不足,将会引发路基的滑塌、沉陷、开裂等危害,进而影响道路的正常使用。为了有效的监测土基的稳定性,有必要找到一种长期有效的监测手段来监测软土地基的工作状态,进而在其影响道路正常使用之前采取相应措施进行加固处理。光纤光栅传感技术的不断发展以及其在工程实际中的不断应用,为软土地基的实时动态监测提供了一种新方法。将光纤光栅传感器应用到工程实际中,不仅可以监测道路路基的工作状态,提供报警信息,还可以为力学分析提供宝贵的实测数据。本文利用软土地基处理中常用的土工格栅作为光纤光栅的封装材料,并对封装方法进行了改良,制作了适用于道路土基监测的传感器。通过室内标定试验对传感器进行标定,得出该传感器的灵敏度系数,并且该系数与裸光纤本身的灵敏度系数非常接近,可以满足道路监测的需要。将传感器埋设于安哥拉实验路的土基中,在路面施工完全结束之后监测了试验路段在移动荷载下的应变变化情况,处理分析采集的数据,并观察传感器的成活率及工作状态。此外,利用有限元软件ABAQUS模拟了施加荷载的过程,依据实际道路结构建立了相应的路面力学分析模型,对比分析了模拟分析的结果与道路实测数据的处理结果,验证了FBG监测技术的可靠性。结果表明,该封装方法既可以很好地保护光纤光栅,又可以保证其测得数据的可靠性,满足道路土基监测的需要,为土基监测提供了一种新的方法。
[Abstract]:In recent years, highway transportation in China has made great progress. With the large-scale construction of highway, the problem of soft soil foundation treatment is becoming more and more important. Although the reinforcement method of soft soil foundation is more and more perfect, it can make it settle and be strong enough, but its long-term stability is also an important problem. If the soft soil foundation is not handled properly or is not stable enough in the later period, it will cause the collapse, subsidence and cracking of the roadbed, and then affect the normal use of the road. In order to effectively monitor the stability of soil foundation, it is necessary to find a long-term effective monitoring method to monitor the working state of soft soil foundation, and then take appropriate measures to strengthen the soil foundation before it affects the normal use of roads. The continuous development of fiber Bragg grating sensing technology and its application in engineering practice provide a new method for real-time dynamic monitoring of soft soil foundation. The application of fiber Bragg grating sensor to engineering practice can not only monitor the working state of roadbed, provide alarm information, but also provide valuable data for mechanical analysis. In this paper, the geogrid, which is commonly used in soft soil foundation treatment, is used as the packaging material of fiber Bragg grating (FBG), and the encapsulation method is improved, and the sensor suitable for road soil foundation monitoring is made. The sensitivity coefficient of the sensor is obtained through indoor calibration test, and the sensitivity coefficient of the sensor is very close to that of bare fiber itself, which can meet the needs of road monitoring. The sensor is embedded in the soil foundation of the experimental road in Angola. After the completion of the road construction, the strain changes of the test section under moving load are monitored, the collected data are processed, and the survival rate and working state of the sensor are observed. In addition, the process of loading is simulated by the finite element software ABAQUS, and the corresponding road mechanics analysis model is established according to the actual road structure. The results of simulation analysis are compared with the processing results of the measured road data. The reliability of FBG monitoring technology is verified. The results show that the encapsulation method can not only protect FBG well, but also ensure the reliability of the measured data. It can meet the needs of road soil foundation monitoring and provide a new method for soil foundation monitoring.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1

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