Strain test of bare FBG under high pore water pressure

Bare Fiber Bragg grating(FBG) as the test components is smart size, waterproof and resistance to electromagnetic compared with the resistance strain gauge(RSG), which make strain tests under the high pore water pressure be possible. Taking corresponding experiment as background, strain tests of bare FBG under the high pore water pressure was studied. First, the effect of different kinds of adhesives on strain sensitivity coefficient and long-term stability of bare FBG was analyzed. At last, the HY-914 was adopt as adhesive of bare FBG to apply to the experiment of hydraulic load of structure in porous rock aquifer. Compared with RSG, it is found that both measured values are close and the change trends are same to each other, strain tests of bare FBG under high pore water pressure is feasible, sensible and precise. Standardization process, kind of adhesives and survival rate are important factors affecting success of model test.