This　paper　focuses　on　laboratory　experiments　designed　to　investigate　the　influence　of　dynamic　shaking　on　water　level　fluctuations　in　boreholes　completed　in　unconsolidated　sediments.　A　large　flume　filled　with　natural　sandy　sediments　was　subjected　to　horizontal　dynamic　loading　at　different　frequencies　(0.5–15　Hz)　and　accelerations　(0.1　g,　0.15　g,　0.25　g　and　0.5　g),　generated　by　a　shaking　table.　Thus,　the　change　in　characteristics　of　the　water　and　saturated　sediments　were　investigated,　i.e.　how　water　levels　and　hydraulic　properties　change　with　time,　are　of　significant　interest.　A　range　of　different　of　water　level　changes　following　oscillating　pore　pressure　for　hydrostatic　and　hydrodynamic　(flowing)　conditions　were　observed:　oscillation,　step-rise,　step-rise　with　oscillation,　and　step-drop　with　oscillation,　similar　to　those　observed　in　the　field　after　earthquakes.　We　found　that　water　level　declines　occur　when　the　imposed　frequency　is　less　than　2　Hz,　while　the　magnitude　of　acceleration　shows　weak　correlation　with　the　water　level　change　when　it　is　less　than　0.5　g.　Sinusoidal　wave　propagation　reduces　hydraulic　conductivity　first　sharply,　stabilizes,　and　is　then　followed　by　a　constant　value　with　a　slight　increase.　Heterogeneous　consolidation,　mechanical　resonance,　compaction,　dilation,　and　re-packing　of　the　grain　structure　may　constitute　physically　plausible　mechanisms　for　water　level　fluctuations　and　hydraulic　parameter　adjustment.　Laboratory　experiments　can　therefore　provide　an　insight　and　a　quantitative　process-oriented　approach　to　better　understand　groundwater　level　response　to　seismic　waves.　©　2021　Elsevier　B.V.