Ecologia undertook an extensometer trial in December 2018 at landfill site near Crawley that is being developed for mixed residential/commercial use. The trial involved drilling and installing multi-point extensometers within 2No. positions and then monitoring the settlement remotely for a number of months whilst up to 9m of surcharge was placed to allow consolidation to take place. Ecologia was able to value engineer the monitoring process using a wireless sensor network to transmit and receive data remotely from the rod extensometers (as it has been successfully undertaken on Vibrating Wire Piezometers currently being monitored by Ecologia) to reduce the requirement for visits to the site (as the data can be accessed 24/7).

After a detailed review of the date the trial has been deemed a success and Ecologia have now been instructed to install a further 25No. on a different part of the site. This area, which was not meant to be surcharged until the end of the programme can now have over 250,000m3 of fill material placed upon it and surcharging started early allowing the original programme to be reduced up to 9 months ahead of schedule. This is possible due to the Ecologia monitoring the settlement remotely allowing the client to use their resources elsewhere. More about the importance of the geotechnical challenges with quarry/landfill  rehabilitation and the advantages that an early engagement of a  specialist may provide for planning surcharge work can be found in our BLOG SESSION.