Experimental research on a novel spring-shaped fiber-optic displacement sensor for settlement monitoring

•An innovative spring-shaped fiber-optic displacement sensor (SSFODS) based on OTDR for settlement monitoring is proposed.•The SSFODS shows high linearity with the R2 of 0.985, large measurement range of 90 mm, minimum displacement resolution of 0.173 mm, maximum hysteresis error of 2.81% and maximum repeatability error of 8.42%, respectively.•Several SSFODSs can be connected in series on one optical link to realize quasi-distributed sensing monitoring.