BOTDA based investigation on the effects of closure strips in bottom plate during the construction of navigation lock

The effects of closure strips was investigated by combining a distributed optical fibre sensing technology with a conventional monitoring scheme for analysing strain distribution, subsidence, earth pressure, and structural stress. It was found that the changes of the structural stress in each block were small and the strain distribution on the block surface was uniform. The closure strips effectively reduced the stress concentration and cracks induced by differential settlement and earth pressure of different RC blocks. The lock head BP underwent coordinated deformation after the sealing of the closure strips. This indicated that the construction of blocks exerted negligible interactive effects because of the closure strips. The results of some conventional point sensing methods, such as the rebar stress, earth pressure and subsidence show the same conclusion. The feasibility and effectiveness of distributed optical fibre sensing technology for structural monitoring of navigation lock construction were also verified.