Experiment and numerical study on the monitoring of super long cast-in-place pile temperature based on BOTDR technology

Abstract In order to obtain the temperature variation of super long cast-in-place pile, the monitoring test of pile temperature is carried out based on Brillouin Optical Time Domain Reflectometer (BOTDR) technology. The results show that the temperature decreases with the depth gradually, it decreases under the ground and the temperature variation is little between 18m and 111m in depth. The temperature variation of pile top monitored by optical fiber sensor and air temperature variation are compared, it shows that the temperature variation of pile top is basically in accordance with air temperature variation. The numerical model is built to study the temperature variation of super long cast-in-place pile, the monitoring and numerical results are analyzed together according to the site situation, and it proves that the trend of numerical simulation and optical fiber monitoring results are consistent.