Safety Inspection Strategy for Earth Embankment Dams using Fully Distributed Sensing

Both the changes in temperature and strain during the process are used to reveal serious seepages and settlements occurring inside the embankment dam. A method for seepage and settlement monitoring in earth embankment dams using fully distributed sensing along optical fibres is proposed. The proposed monitoring system also offers the owner the strategy of the inspection and maintenance in earth embankment dams. The database in the control and maintenance center is described. In this paper, as an example, a model filled with the soil from Yellow River is built and bare optical fibers are embedded under different soil layers near the seepage path. The configuration of optical sensing cable in series of embankment dams is developed. The simulated seepage flows under various flow rates are monitored using the optical fibers and measured by a DiTeSt –STA202 distributed temperature and strain analyzer. A partial settlement within the embankment dam model is observed. The continuously decreasing temperature curve shows an abrupt dramatic increasing rate, which shows that the change is not caused by the temperature of the seepage water but the strain. The information from the monitoring center provides important reference for the expert decision-making system to ensure the safety of the embankment dam long running.