一种用于滑坡监测的复合光纤装置

针对滑坡体深部位移这一重要指标,基于光时域反射技术,设计了一种蝴蝶结形式的复合光纤装置用于监测深部剪切位移.该传感装置由方形聚氯乙烯树脂管、毛细钢管、光纤、砂浆组合而成.首先在40mm×40mm×500mm(厚2.0mm)的聚氯乙烯树脂方管四周开挖导槽,将Φ1×500mm毛细钢管放置在导槽中.然后用光纤穿入毛细钢管,光纤一端固定,另一端绕制成蝴蝶结形式.最后在聚氯乙烯树脂管外围浇筑Φ110mm的砂浆,制作成圆柱式复合光纤装置.室内边坡模型剪切测试台测试结果表明:该装置对深部剪切位移初测准确度为1mm,最大测量范围为40mm.分析表明该复合光纤装置具有灵敏度高、测量范围大、结构简单易于安装等优点,可以用于滑坡以及野外岩土结构工程等进行现场原位监测.

A Composite Optical Fiber Transduser for Landslide Monitoring

Aimed at the important indicator of deep displacement in landslide body,based on the optical time domain reflection technique,a composite optical fiber transducer was designed to monitor the deep shear displacement.The transducer is composed of square PVC pipe,capillary pipe,optical fiber and mortar.Firstly,the surrounding of 40 mm×40 mm×500 mm (2.0 mm thick) PVC tube was grooved,and the Φ1×500 mm steel capillary was placed in the guide groove.Then the fiber was used to penetrate capillary tube.One end of the optical fiber was fixed,and the other end was wound into a bow form.At last,the mortar with diameter of 110 mm was poured outside PVC,so that a cylindrical composite optical fiber transducer was fabricated.The slope model shear test experiment shows the transducer detection accuracy is 1 mm and the maximum measurement range of fiber grating is 40 mm.Study shows that the composite optical fiber transducer has the advantages of high sensitivity,wide measuring range and convenient installation,and can be used for in-situ landslide monitoring and geotechnical engineering structure monitoring effectively.