Method for monitoring compression and tensile deformation of stressed rod piece based on optical fiber sensing technology

The invention discloses a method for monitoring compression and tensile deformation of a stressed rod piece based on an optical fiber sensing technology. The method comprises the following steps thatdifferent sensing optical cables, namely quasi-distributed steel bar stress sensing optical cables or quasi-distributed fiber bragg grating strain sensing optical cables, are selected for installationaccording to the type of the supporting rod piece in a to-be-detected area in a foundation pit support structure, and the sensing optical cables are connected with an FBG demodulator; the FBG demodulator sends out a broadband optical signal, transmits the broadband optical signal to the sensing optical cable and reflects a group of narrow-band light with different wavelengths; when the sensing optical cable changes along with the supporting rod piece, the resonance wavelength of the sensing optical cable drifts, the wavelength of reflected narrow-band light is recognized through the FBG demodulator, the wavelength cha