ABSTRACT
The HS2 tunnelling works in the United Kingdom required extensive ground movement assessment (GMA) for existing third party bridges to identify which assets might be susceptible to damage and require mitigation measures, and to provide a basis for screening out structures likely to suffer negligible damage. This paper presents an overview of the GMAs conducted on approximately 80 existing bridges located above the future twin-bored, tunnelled, HS2 route, focusing on the challenges faced, methodologies employed, and findings obtained. The GMAs ensured that detrimental effects of HS2 construction on existing assets were identified early and impacts to those assets were minimized, reducing overall project expenditure with risk-based damage assessment. This paper shares the learning points from assessing a large sample of bridges of various ages and structural types under the influence of tunnel-induced ground movement. Findings include recommended monitoring, remedial works, or mitigation outcomes grouped by bridge type.
