http://researchonline.federation.edu.au/vital/access/manager/Index ${session.getAttribute("locale")} 5 http://researchonline.federation.edu.au/vital/access/manager/Repository/vital:16042 300m) horizontal bores. Features observed using the camera along the profile of horizontal bores are discussed. Water flow was quantified by flow meters. X-Ray Diffraction (XRD) was undertaken to investigate the water precipitates within the selected bores. Water flow temperature was recorded to test the hypothesis of a possibility to indicate whether a borehole was draining from the saturated zone or from the surface water through its temperature. The investigations have been conducted to determine the cause of change in the efficiency of horizontal boreholes and find a reliable measure to assess longevity and performance of horizontal drains. Bore efficiency has been defined as the bore functioning as a preferential path for water within the batter to be drained out to reduce the saturated zone and associated pore water pressures within the batter. The results suggest blockages and fractures inside the bores can be considered the leading cause of the change in the efficiency of a bore. Blockages occur because of sediment accumulation and because of coal chunks from internal wall collapses. Internal fractures affect efficiency when they become the water preferred path; thus, retaining water flowing within the batter. The bore’s longevity is considered the period of the bore is considered effective. Water flow measurement is suggested as a reliable measure to assess bores’ longevity.]]> Tue 10 May 2022 11:21:59 AEST ]]> http://researchonline.federation.edu.au/vital/access/manager/Repository/vital:15201 Thu 02 Sep 2021 14:17:07 AEST ]]>