Design and Implementation of Geophysical Monitoring and Remote Sensing during a Full-Scale Embankment Internal Erosion Test

Abstract

This paper describes the conception and deployment of a multi-geophysics and remote sensing approach to monitoring internal erosion in a test embankment that was loaded to increase seepage and initiate internal erosion in Booneschans, Netherlands in fall 2013. IJkdijk is a full-scale field testing embankment constructed to facilitate sensor validation testing for monitoring embankment loading and failure conditions. The embankment was constructed of a single zone high plasticity clay embankment with sand foundation. The test embankment was subjected to reservoir loads simulating tidal and storm surge conditions known to induce internal erosion in actual embankments. Geophysical monitoring of subsurface conditions was pursued using self-potential and passive seismic methods. Concurrent terrestrial lidar remote sensing methods were implemented to track millimeter scale deformation. Each of these monitoring approaches was implemented successfully and yielded useful spatial and temporal information throughout the seven days of testing, from initial reservoir loading to completion of the test.

Time-lapse monitoring of internal erosion in earthen dams and levees using ambient seismic noise

“…This is consistent with all other data from the experiment; that is, pore water pressure was constant ( Fig. 13) and there were no local observations of internal erosion in these areas (Mooney et al, 2014). Sensor pair 2 shows a gradual decrease in local surface wave velocity from T ¼ 35 h to T ¼ 110 h that is consistent with the gradual increase in local pore water pressure response and consequent decrease in local effective stress.…”

“…Relative velocity changes for the 1•8 m offset sensor pairs, along the first 4 h of the experiment. The largest velocity drop (% 20%) is observed around the centre of the structure, where the piping process is expected to induce strong stress redistributions terrestrial Lidar(Mooney et al, 2014;Rittgers et al, 2014). The work presented here focuses on the analysis of the passive seismic data.…”

Investigation of remote sensing for dike inspection

“…A standard classical measurement of groundwater levels in dikes makes use of standpipes or more sophisticated piezometers for pore water pressure measurements that may be used to indicate instability, (Fargier et al, 2012;Niederleithinger et al, 2012;Perri et al, 2014;van Leeuwen et al, 2007) Electromagnetic induction dike material composition/type, intrusions, material interfaces, water content (Bishop et al, 2003;Boukalová et al, 2009;Niederleithinger et al, 2012;Perri et al, 2014;Viganotti et al, 2013) Ground penetrating radar (GPR) intrusions, voids, discontinuities (Di Prinzio et al, 2010;Niederleithinger et al, 2012;Perri et al, 2014) Seismic lithological layers, bedrock depth (Lorenzo et al, 2014;Niederleithinger et al, 2012) seepage or groundwater flow (e.g., vibrating wire; Ng and Oswalt, 2010;Pengel et al, 2013). Other established sensor technologies used for geotechnical measurements which are investigated or used for dikes include voltmeters (connected to electrodes) for measuring self-potential indicative of water flow (Mooney et al, 2014;Ng and Oswalt, 2010;Rittgers et al, 2015); tensiometers for measuring soil water potential related to instability or seepage (Weller et al, 2014); inclinometers for local or global tilt indicting displacement or deformation (e.g., coaxial cable); strain and stress measuring devices (e.g., pressuremeters) and geophones and microphones (e.g., luisterbuis or listening tube) for passive seismic monitoring of vibrations and acoustic emissions related to seepage and internal erosion (Mooney et al, 2014;Rittgers et al, 2015;Weijers et al, 2009). Table 1.4 provides an overview of some recent research on newer in-or on-dike sensor technologies.…”