A site in Partick and another in Easterhouse can share the same building design yet sit on completely different ground profiles. The Clyde alluvial deposits that underlie much of the city centre amplify seismic waves in ways that the glacial till beneath the northern suburbs simply does not. We run seismic microzonation studies that capture this variation, producing amplification maps and Vs30 grids so engineers know exactly what each Glasgow postcode demands. The work ties directly into the city’s Local Development Plan and the requirement for ground investigation reports to address seismic hazard under BS EN 1998‑1:2004. For sites where the bedrock dips sharply beneath soft sediments, we often combine the zonation output with a targeted MASW survey to refine the shear‑wave velocity model before finalising foundation parameters.
Glasgow’s post‑industrial ground conceals sharp impedance contrasts that can double spectral acceleration over distances of less than 100 m.
Questions and answers
When does Glasgow City Council require a seismic microzonation study?
The council’s planning department routinely conditions seismic hazard assessments for major developments, high‑rise structures, and critical infrastructure. The trigger is typically set out in the Local Development Plan, referencing BS EN 1998‑1. If the site sits on alluvial deposits along the Clyde corridor or on variable made ground, a microzonation study demonstrates that ground amplification has been properly characterised rather than assumed.
How is the Vs30 profile obtained for a Glasgow site?
We combine direct downhole seismic testing in boreholes with surface‑wave methods, usually MASW or cross‑hole surveys, depending on access and depth to bedrock. The shear‑wave velocity profile is then calibrated against dynamic laboratory tests — resonant column and bender element — run on undisturbed samples recovered from each distinct stratum. This dual approach reduces the uncertainty that comes from relying on a single measurement technique.
What is the typical cost range for a seismic microzonation study in Glasgow?
The price depends on the number of measurement points, the depth of investigation, and the laboratory programme. For a mid‑rise development covering 0.5 to 2 hectares, the study typically falls between £3,200 and £11,520. A fixed quotation is provided once we review the site geology, the proposed structure, and any specific planning conditions attached to the application.
Can the microzonation output be used directly by the structural engineer?
Yes. We supply the design ground motion parameters — spectral ordinates, amplification factors, and site class — in a format that feeds directly into structural analysis software. Where the site straddles more than one ground type, we delineate the boundaries on a plan so the structural team can assign different response spectra to different parts of the building footprint.
