OFDR光纤传感技术在十字岩柱暗挖法物理模型试验中的应用

发布时间：2018-02-21 11:58

本文关键词： 隧道工程十字岩柱模型试验光纤传感器应变分布光频域反射(OFDR) 分布式监测　出处：《岩石力学与工程学报》2017年05期 　论文类型：期刊论文

【摘要】：现阶段岩土工程模型试验围岩变形监测多采用点式传感器,仅能获得部分测点的应变,而光纤传感作为一种迅速发展的分布式监测技术,能很好地解决这一问题。对于岩土工程室内试验,现有光纤传感技术无法满足试验对空间分辨精度的高要求。对一种新型光纤传感技术光频域反射技术(OFDR)的测量原理和优点进行介绍,并将其应用于浅埋超大断面圆形隧道十字岩柱开挖模型试验中,对整个模型不同断面进行水平向应变连续监测。根据试验结果,结合有限元分析,表明OFDR能准确记录试验过程中模型内部的应变变化,揭示围岩在十字岩柱开挖方法下的变形规律,反映十字岩柱对围岩的支撑作用,为今后隧道工程开挖提供参考。另外通过算法将应变结果转化为位移结果,并与多点位移计的监测结果进行对比分析,偏差在10%以内。结果表明,该技术可应用于岩土工程试验中的变形监测。
[Abstract]:In the present geotechnical engineering model test, the deformation monitoring of surrounding rock is mostly based on point sensor, which can only obtain the strain of some measuring points, while optical fiber sensor is a rapidly developing distributed monitoring technology. Can solve this problem very well. For geotechnical engineering indoor test, The present optical fiber sensing technology can not meet the high requirement of the spatial resolution precision of the experiment. The measurement principle and advantages of a new optical fiber sensing technology, optical frequency domain reflectance technique, are introduced in this paper. It is applied to the model test of cross rock column excavation of shallow and super-large section circular tunnel. The horizontal strain of different sections of the model is continuously monitored. According to the test results, combined with finite element analysis, The results show that OFDR can accurately record the strain changes in the model during the test, reveal the deformation law of the surrounding rock under the method of cross pillar excavation, and reflect the supporting effect of the cross rock column on the surrounding rock. In addition, the strain result is transformed into the displacement result by the algorithm, and compared with the monitoring result of the multipoint displacement meter, the deviation is less than 10%. The result shows that, This technique can be applied to deformation monitoring in geotechnical engineering tests.
【作者单位】：中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;武汉大学岩土与结构工程安全湖北省重点实验室;中建南方投资有限公司;武汉隽龙科技股份有限公司;
【基金】：国家自然科学基金面上项目(51474205)~~
【分类号】：U456

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