With over 20 years' experience in shaft construction and ancillary activities, Mancala is able to provide its clients with:
Over recent years Mancala has seen an increasing requirement for shaft support which incorporates speed of installation, structural certification and flexibility. As a consequence Mancala has adapted and improved the process of using galvanised steel liners as a non-entry method of ground control for vertical raise bored shafts.
The concept uses modular liner segments which are assembled as the installation is lowered into the shaft immediately following the raise boring activity. The method which can incorporate grouting of the shaft/liner annulus has been used on shafts up to 5.5m in diameter and in excess of 320m depth with the total liner segments weigh over 240 tonnes.
Off site fabrication and on site assembly during raise boring allows installation rates of up to 40 metres per day. Adaption of the liner design to incorporate ladderways for second egress or service lines are available.