Abstract:
The presence of a significant thickness of soft silts beneath the site of a proposed new
road bridge caused concerns over the suitability of shallow foundations. Despite extensive
conventional ground investigations, it was not possible to obtain reliable stiffness data, and so a
full-scale, fully instrumented load test was undertaken to better determine ground stiffness. The
data obtained was used in conjunction with sophisticated numerical analysis to demonstrate that
the settlement of shallow foundations would be acceptable. Following completion of the bridge
construction, Continuous Surface Wave testing was undertaken and a range of simple non-linear
elastic settlement analyses conducted to model the behaviour of the load test. Through these
analyses this paper demonstrates the benefit of using continuous surface wave ground stiffness
testing in conjunction with simple analysis methods. It underlines the importance of obtaining
high-quality stiffness data to accurately predict settlement of shallow foundations.
