Construction monitoring of lock head base plate using distributed optical fibre sensing technique

Song Zhanpu 1,2 Shi Bin 1, Zhu Honghu 1, Shen Mengfen 2, Zhang Dan 1, Sun Yijie 1

1 School of Earth Sciences and Engineering, Nanjing University,  Nanjing 210023, China

2 Glenn Department of Civil Engineering, Clemson University, Clemson,  SC 29634, USA

Journal of Southeast University (English Edition), 2015, Vol. 31, No. 4, pp. 535-540 

doi: 10.3969/j.issn.1003-7985.2015.04.018

Abstract: The concrete hydration heat release process of the base plate is monitored using Raman optical time domain reflectometry (ROTDR) sensing sensors. The monitoring data shows that the internal maximum temperature of the base plate is about 54 degree after the concrete was cured for 120 h. The fiber Bragg grating (FBG) temperature sensors are adopted to measure the surface temperature of the concrete and the temperature results are used to compensate the data measured by the pulse-prepump Brillouin optical time-domain analyzer (PPP-BOTDA) to obtain the real concrete surface strain of the base plate. The monitoring data is analyzed to obtain a clear understanding of the strain state of the base plate under the effect of concrete hydration heat release. The monitoring results demonstrate the potential of distributed optical fibre sensing techniques as a powerful tool in real-time construction monitoring, and also provide an important insight into the design, construction and maintenance of large hydraulic structures.

Key words: construction monitoring; lock head base plate; optical fibre sensing; lock engineering; concrete