Device and method for testing temperature conduction and frost-heaving strain of concrete lining canal

A device for testing temperature conduction and frost-heaving strain of a concrete lining canal, comprising:

• a frost-heaving device comprising a lining canal body and a temperature control device, wherein
• the temperature control device is configured to provide a predetermined temperature for the lining canal body;
• a detection device comprising a transverse deformation detection device, a vertical displacement detection device and a plurality of temperature sensors, wherein
• the transverse deformation detection device is configured to detect a transverse frost-heaving strain parameter of the lining canal body at the predetermined temperature;
• the vertical displacement detection device is configured to detect a vertical frost-heaving strain parameter of the lining canal body at the predetermined temperature;
• the plurality of temperature sensors are arranged along an axial direction of the lining canal body;
• the plurality of temperature sensors are embedded inside the lining canal body;
• and
• the plurality of temperature sensors are configured to detect temperature conduction performance of the lining canal body at the predetermined temperature,
• wherein the transverse deformation detection device comprises:
• a plurality of groups of single-mode bend-insensitive optical fibers, a temperature compensation device and a Fiber Bragg Grating (FBG) demodulator;
• the plurality of groups of single-mode bend-insensitive optical fibers are tightly sleeved on an overall outside of the lining canal body, and the plurality of groups of single-mode bend-insensitive optical fibers are electrically connected to the FBG demodulator;
• the temperature compensation device is arranged inside the lining canal body and is electrically connected to the FBG demodulator.

A method for testing temperature conduction and frost-heaving strain of a concrete lining canal, wherein the method is applied to a device for testing temperature conduction and frost-heaving strain of a concrete lining canal, the device comprising:

• a frost-heaving device comprising a lining canal body and a temperature control device, wherein the temperature control device is configured to provide a predetermined temperature for the lining canal body:
• a detection device comprising a transverse deformation detection device, a vertical displacement detection device and a plurality of temperature sensors, wherein the transverse deformation detection device is configured to detect a transverse frost-heaving strain parameter of the lining canal body at the predetermined temperature;
• the vertical displacement detection device is configured to detect a vertical frost-heaving strain parameter of the lining canal body at the predetermined temperature;
• the plurality of temperature sensors are arranged along an axial direction of the lining canal body;
• the plurality of temperature sensors are embedded inside the lining canal body;
• and the plurality of temperature sensors are configured to detect temperature conduction performance of the lining canal body at the predetermined temperature, the method comprising:
• S1, performing an initial detection, specifically comprising:
• detecting, by an FBG demodulator, an initial center wavelength λB of a pre-tightening force of a plurality of groups of single-mode bend-insensitive optical fibers sleeved on the lining canal body;
• detecting, by the plurality of temperature sensors, an initial temperature of the lining canal body;
• S2, configuring the temperature control device to provide the predetermined temperature for the lining canal body, specifically comprising:
• performing, by an upper temperature-changing box and an lower temperature-changing box, refrigeration to provide the predetermined temperature for an upper end and a lower end of the lining canal body;
• S3, detecting after temperature changing, specifically comprising:
• detecting, by the plurality of temperature sensors, a temperature change ΔTi of different regions of the lining canal body;
• detecting, by the FBG demodulator, a central wavelength changing value ΔλBi of the plurality of groups of single-mode bend-insensitive optical fibers caused by the temperature changing;
• detecting, by the FBG demodulator, a strain changing value si of the plurality of groups of single-mode bend-insensitive optical fibers;
• detecting, by a displacement sensor, a vertical displacement change of the lining canal body;
• S4, obtaining a frost-heaving strain parameter:
• calculating a transverse frost-heaving strain of the single-mode bend-insensitive optical fibers:
• Δ
• ⁢
• λ
• Bi
• λ
• B
• =
• (
• α
• +
• ξ
• )
• ⁢
• Δ
• ⁢
• T
• i
• +
• (
• l
• -
• p
• e
• )
• ⁢
• ε
• i
• wherein εi is a detection value of the transverse frost-heaving strain of the single-mode bend-insensitive optical fibers in the different regions, α is a thermal expansion coefficient of the single-mode bend-insensitive optical fibers, ξ is a thermo-optic coefficient of the single-mode bend-insensitive optical fibers, and pe is an effective photoelastic coefficient of the single-mode bend-insensitive optical fibers;
• calculating a transverse frost-heaving strain εai of the lining canal body:
• εai=εi−ε′
• wherein εai is an actual value of the transverse frost-heaving strain of the lining canal body in the different regions, εi is the detection value of the frost-heaving strain of the single-mode bend-insensitive optical fibers in the different regions, and ε′ is an error value detected by a temperature compensation device;
• obtaining a vertical frost-heaving strain parameter of the lining canal body by the displacement sensor provided at a second end of a fixing rod.