Dr Toby Roberts, the Chairman of WJ, gave a fascinating presentation on dewatering cross passages using in-tunnel well systems. The presentation was one of the features at the 3rd Arabian Tunnelling Conference & Exhibition 2015 held in Dubai, UAE in November.
Toby’s presentation focused on a specific cross passage, Crossrail CP6, which, despite challenging ground conditions and programme constraints, WJ was able to dewater successfully. The installations were carried out using techniques developed at WJ that allows probe holes and dewatering wells to be installed from inside tunnels and basements under high external water pressure. The dry cross passage was constructed by main contractor Dragados Sisk JV using an open face timber heading with SGI rings and reinforced concrete collars. WJ has used these techniques to install dewatering systems to allow the repair of leaking basements and tunnels where there has been an external head of water in excess of 10 metres. The dewatering was carried out using a combination of inclined wellpoints and ejector wells.
To learn more about the event in general please visit our previous article here.
Please visit our What We Do page to discover even more about our Groundwater management projects. You can also phone +44 (0)20 8950 7256 to discuss your project ideas and options today.
Photos by Ollie Vincent