Engineering interpretation

Approaches for interpreting the analysed data from fibre optic (FO) sensors into useful engineering information are presented in this chapter. Four example applications are discussed that refer to the most common applications of FO sensing in geotechnical engineering: foundation piles, retaining walls, tunnels and slopes.

The procedure for interpreting the spatially continuous DFOS strain data from pile load tests for axially loaded piles is described. Vertical reinforced-concrete foundation piles, which can be monitored with FO sensor cables attached on the reinforcement steel cage prior to concrete casting, are considered here. Similarly, steel piles (circular, hollow, H, etc.) can be considered in cases where the FO cables have been fully bonded to the shaft. Here, the basic steps for interpreting axial strains from FO sensors are provided and the interested reader is referred to Pelecanos et al. (2016a, 2016b) and Pelecanos and Soga (2016) for more details and relevant examples of application.