A40 Brecon bypass landslide: investigation, remediation and asset management for climate resilience

Abstract

During February 2020, a 300 m 3 slope failure occurred within a trunk road earthwork at Brecon, Wales, leading to the initial closure of all four lanes of the dual carriageway. As part of Welsh Government's strategy for climate resilient infrastructure and in accordance with the CD622 Managing Geotechnical Risk framework, the site investigation commenced in 2020 and proceeded through various phases to the completion of remedial works in 2022. This paper discusses the approach to management of geotechnical risk for the scheme, from desk study through implementation of an on-slope ground investigation and interim risk mitigation, to design and implementation of the remedial measures. The paper describes the nature and trigger of the landslide case study, adaptations in the design phase to provide resilience to geohazards and future climatic conditions, the constraints that were overcome during the site works and measures taken to manage residual risk and ensure ease of maintenance. Thematic collection: This article is part of the Geo-resilience and infrastructure collection available at: https://www.lyellcollection.org/topic/collections/geo-resilience-and-infrastructure