Everything about N-OT04 Overtopping Test (Artificial burrow) id;activity_name;activity_type;activity_descriptor;breaching;animal;erosion;temporary;levee_survey;prolonged;start_date;end_date;date_length_day;date_length_hour;date_other;levee_stretch;location_x;location_y;location_z;location_descriptor;location_other;objectif_important;objectif_knowledge;pre_condition;act_des;monitoring_process;monitoring_reasoning;limits;during_activity;post_activity;activity_result;results_conc;knowledge_desc;ref_links;wrk_1;wrk_2;wrk_3;key_info 172;N-OT04 Overtopping Test (Artificial burrow);Strength test;This test was executed on a ‘test section with a uniform vegetation cover’, with only few bare spots, irregularities and holes. Artificial burrows in the higher part of the slope were drilled. The slope is 1:2,5.;False;True;True;False;False;False;;;2;;;VI;;;12.0;Landward slope of levee;;Longer artificial burrows in the higher part of the slope were drilled.;Impact of animal activity on cover strength;Levee slope is visually in good condition.;The following wave sets were consecutively applied: 0,5m60lsm and 1m190lsm (twice), 2m50lsm (30’) and 1m190lsm (2x 15’).;;;;When after 3 sets of wave no failure of the cover was imminent, 2 longe(r) artificial burrows were created, adjacent in the higher part of the slope, again with a diameter 10 cm but by increasing the total length of the pipe (inlet of pipe at an angle of 45°, outlet of pipe at an angel of -12,5°). Both pipes were connected within the sandy core. Applying wave set ‘2m50lsm’ for 30 minutes both pipes showed washout of sand. Continuing with the wave set ‘1m190lsm’, transport of sand remained and after 15’, sudden, a pit was formed at the inlet of 1 pipe. Gradually this pit eroded further and found connection to the other pipe inlet.;At the end, a step of 3m by 4m with a cliff of 1 m height was formed. The outlet pipes were still in place.;Pipes connecting to the sandy core and having sufficient lenght can give rise to sudden collapse of the cover layer.;;;;True;False;False; All DATA concerning N-OT04 Overtopping Test (Artificial burrow) No data added All EQUIPMENTS concerning N-OT04 Overtopping Test (Artificial burrow) No equipment added All SENSORS concerning N-OT04 Overtopping Test (Artificial burrow) No sensors added