In Dundee, seismic assessment must account for the complex interface between the city’s volcanic bedrock and the thick alluvial deposits of the Tay Estuary. The UK’s Eurocode 8 framework, while nominally low-seismicity, demands rigorous evaluation where soft soils amplify ground motion. Our seismic category addresses this through targeted soil liquefaction analysis, critical for the saturated silts and sands prevalent along the waterfront, and seismic microzonation, which maps variable site response across the city’s distinct geological domains.
These investigations are integral to the design of foundation systems for multi-storey developments, port infrastructure, and energy projects within the Dundee Waterfront regeneration zone. A seismic microzonation study provides the spatial framework, while a detailed soil liquefaction analysis informs Improvement strategies, ensuring structural resilience and compliance with British Standards for dynamic loading.
Seismic site assessment in Dundee addresses the evaluation of ground behaviour under earthquake loading, despite the region’s low-to-moderate seismicity. The local geology, dominated by glacial tills, raised beach deposits, and the Dundee Formation igneous bedrock, creates variable impedance contrasts that can amplify ground motion. Our approach aligns with BS EN 1998-1 (Eurocode 8) and the UK National Annex, ensuring compliance with current structural design requirements. A detailed investigation programme establishes the seismic ground type, while In-Situ directly measures the small-strain stiffness and cyclic degradation potential of these Quaternary and bedrock units.
Methodology follows BS EN 1998-1 and BS 5930 for site classification, relying on shear wave velocity (Vs) profiles and Standard Penetration Test N60 values. We deploy SPT at regular depth intervals to assess relative density and liquefaction susceptibility in saturated granular layers beneath the Tay Estuary margins. For fine-grained glacial till, CPT provides continuous soil behaviour type classification and pore pressure data, essential for cyclic softening analysis. Where bedrock is shallow, Ménard pressuremeter test (PMT) campaigns yield the in-situ modulus and allow direct evaluation of rock mass stiffness under seismic shear strain. A laboratory programme on undisturbed samples quantifies plastic index, cyclic triaxial resistance, and bender element Vs, calibrating the field data.
Typical Dundee projects include waterfront regeneration schemes along the River Tay, where loose alluvial sands and silts require rigorous liquefaction assessment, and the redevelopment of historic mill structures on stiff glacial till, where site-specific response spectra often reduce foundation demands compared to generic Type D assumptions. We also support critical infrastructure such as substation upgrades and bridge pier assessments for the Tay Road Bridge approaches, where residual soil characterization of weathered igneous rock governs the seismic earth pressure and slope stability calculations. Each project demands a tailored seismic hazard assessment, integrating the British Geological Survey’s 1:50,000 scale maps with our intrusive data.
The process delivers a concise Ground Investigation Report containing seismic ground type classification, liquefaction potential index, and response spectra for the ultimate and serviceability limit states. By combining stratigraphic profiling with advanced dynamic laboratory testing, we provide the essential design parameters—Vs, damping ratio, and modulus reduction curves—that structural engineers require for performance-based design. This integrated approach eliminates conservative assumptions, resulting in optimised foundation geometries and resilient designs fully compliant with the current UK regulatory framework.