The invention discloses a distributed
optical fiber sensing system and technical schemes. With the distributed
optical fiber sensing system and technical schemes adopted, the networked and integrated online
telemetry and large-scale multi-parameter space-time
full coverage of the
geomembrane bi-directional strain and joint fracture opening degree of the
geomembrane anti-seepage earth-rockfill dam can be realized, and the scientific and technological content and effectiveness of the
safety monitoring of the
geomembrane anti-seepage earth-rockfill dam can be significantly improved. A large-range composite sensing
optical fiber composed of a unique SM tight tube optic
fiber, a
carbon coated SM optic
fiber and a fluorinated plastic optic
fiber, and a supporting BOTDA type optical
signal demodulator and a supporting OTDR type optical
signal demodulator are adopted; the strain range of the distributed
optical fiber sensing system can be up to 40%, in particular, can simultaneously monitor the occurrence, location and opening degree of the joint fracture of the geomembrane; and therefore, the
upgrade of a conventional point-type electric measurement
strain gauge can be realized, technical blank and difficulty in joint fracture monitoring can be filled and eliminated respectively. An orthogonal sensing
network layout mode, optical fiber laying positioning and solidification techniques and an optical fiber mesh initial field establishing method are provided, so that
engineering practicability can be realized.