一种用于滑坡位移监测的OFDR测斜仪研发

Development of an OFDR inclinometer for landslide displacement monitoring

测斜仪被广泛应用于岩土工程的变形监测,现有传统测斜仪易受电磁干扰,耐腐蚀性弱,点式测量,难以实现分布式实时监测。为克服传统测斜仪的缺点,该文基于共轭梁法和光频域反射技术(OFDR),研制分布式光纤原位测斜仪,并进行数值模拟和实验研究。结果表明,该新型原位测斜仪位移测量结果准确,相对测量误差在±10%以内,多次测量标准差为0.44 mm。与FBG原位测斜仪进行对比,OFDR原位测斜仪在变形监测中距离分辨率更高、位移测量更加精确。OFDR原位测斜仪具有较强的工程实用性,可有效、准确地测量边坡等岩土体的连续变形,实现长期变形监测。

Inclinometers are widely used in deformation monitoring of geotechnical engineering.The traditional inclinometers are affected by electromagnetic interference and poor in corrosion resistance,which makes them can not be used well.What’s more,traditional inclinometers mainly rely on point measurement,which makes it difficult to achieve distributed real-time monitoring.To overcome the shortcomings of traditional inclinometers,a distributed optical fiber in-situ inclinometer is developed based on the conjugate beam method and optical frequency domain reflectance(OFDR).Numerical simulations and laboratory experiments are conducted,the results show that the displacement measurement of the novel in-situ inclinometer is accurate,the relative error is within ±10%,and the standard deviation is 0.44 mm.Compared with FBG in-situ inclinometer,OFDR in-situ inclinometer has higher resolution and accuracy in deformation monitoring.The OFDR in-situ inclinometer has certain significance in engineering application,which can effectively and accurately measure the deformation of rock and soil bodies such as slopes,and can realize longterm deformation monitoring.