Newbridge landslide, Wrexham: Investigation and remediation - Western Regional Group

The Western Regional Group is pleased to welcome Tom St John and Dafydd Tudor who will present on the investigation and remediation of the B5605 Newbridge landslide, Wrexham, North Wales. This is a hybrid event being held both in person and online via Zoom.

The talk will describe the landslide which occurred during Storm Christoph in January 2021. The failure involved the river facing toe of the slope and retaining structures supporting the B5605, within a highly constrained setting. Tom and Dafydd will describe the ground investigations and mapping which revealed a complex ground model and evidence of historical failures and remediation. Methods to sample, test and characterise the weak mudstone of the Etruria Formation will be discussed. The investigations and model enabled understanding of the failure mechanism and material strength, which in turn allowed development of a proportionate, risk based remediation strategy.

Finally, the remedial options, detailed design and construction will be described. The repair comprised of a contiguous piled wall at the river edge to mitigate scour, a new highway retaining wall at the crest and 12,000t of engineered fill. A detailed petrographic assessment demonstrated that material typically perceived as of ‘marginal’ suitability was appropriate for the earthworks, introducing major cost and time savings. The scheme successfully reinstated the road in 2025 as a resilient, long-life asset while minimising environmental impact and future maintenance requirements.

The room opens at 6pm. Non-members are welcome. Zoom room opens at 6.15pm. 

Click on the Book Now button to access the Zoom link. o registration needed for those attending in person.