Apparatus and method for monitoring three-dimensional strain in landslide slip zone

An apparatus for monitoring three-dimensional strain in a landslide slip zone, wherein the apparatus is configured to be installed partially in a landslide body and partially in the slip zone, the slip zone is located just below the landslide body, and a bedrock layer is situated below the slip zone, and the apparatus comprises:

• a strain sensor comprising a protective shell, a slidable rotating cover covering an opening of the protective shell, a fiber Bragg grating (FBG) sensor located inside the protective shell, and a telescopic rod slidably arranged within the protective shell and the slidable rotating cover, wherein the telescopic rod is configured to push the FBG sensor into contact with a stratum to monitor strain information of soil and rock mass in the slip zone;
• a data control module configured to be arranged on a surface of the landslide body, wherein the data control module is electrically connected to a switch of the slidable rotating cover via a data cable;
• the data control module is configured to preprocess data collected by the FBG sensor, save the data in a local database, and transmit the data to a remote monitoring center;
• and
• a magnetic positioning device configured to correct displacement detection orientation errors of the FBG sensor caused by landslide deformation.