Civil Engineering April 2021 | Vol 29 No 3

24 April 2021 Civil Engineering shown. At the start of the measurement period, a limitation of the fixed-matrix porous sensor can be see seen as these sensors have a measuring limit of –9 kPa. It is also clear that the fixed-matrix porous sensor is less sensitive to changes in matric suction than the tensiometer. It is, however, evident that both sensors measured similar trends and provide useful information of seasonal variations in soil suction. CONCLUSIONS Two years ago, Gaspar & Jacobsz (2019) highlighted the importance of unsatu- rated soil mechanics and illustrated how its application in practice had become significantly more accessible. Industry’s response to these developments was over- whelmingly positive, leading to further research on the subject, as well as its im- plementation in practice. Improvements Pore water pressure (kPa) 10 0 –10 –20 –30 –40 –50 Monthly rainfall (mm) 120 100 80 60 40 20 0 1 Jul 2020 1 Aug 2020 1 Sep 2020 1 Oct 2020 1 Nov 2020 1 Dec 2020 1 Jan 2021 1 Feb 2021 Sensor installation Depositions Figure 3 Suction measurements in a platinum tailings storage facility over a period of approximately 8 months Tensiometer 1 Tensiometer 2 Tensiometer 3 Monthly rainfall Pore water pressure (kPa) 10 0 –10 –20 –30 –40 –50 Monthly rainfall (mm) 120 80 40 0 Figure 4 Suction measurements in a gold tailings storage facility over a period of approximately 2 years 20 280 240 200 160 1 Jan 2021 1 Dec 2020 1 Nov 2020 1 Oct 2020 1 Sep 2021 1 Aug 2020 1 Jul 2020 1 Jun 2020 1 May 2020 1 Apr 2020 1 Mar 2020 1 Feb 2020 1 Jan 2020 1 Dec 2019 1 Nov 2019 1 Oct 2019 1 Sep 2019 1 Aug 2019 1 Jul 2019 1 Jun 2019 1 May 2019 1 Apr 2019 Depositions Tensiometer 1 Tensiometer 2 Tensiometer 3 Monthly rainfall