Infrastructure Civil Engineering Satellite Remote Sensing

Westgate Shopping Centre redevelopment 

Predicted ground movement and deflection of the new steel basement walls were too high. Also, the structural engineers needed reliable spring stiffness values for the basement raft design and dewatering advice for this low-lying site near the River Thames in Oxford.

Additional advanced in situ stiffness testing was specified allowing the Oxford Clay to be modelled more precisely. Hence, the predicted ground movement decreased to acceptable levels and accurate spring stiffness values were provided for the raft design. Groundwater flow modelling was also undertaken to estimate pumping rates for permanent basement dewatering options.

Highlights

• Specification of downhole seismic testing for more accurate Oxford Clay stiffness parameters.

• 3D FEA model of demolition, adjacent building foundations and proposed new basement construction.

• Predicted ground movements and differential settlement with existing parts of the shopping centre satisfactory.

• Outputs of coefficient of subgrade reaction provided to structural engineer for basement raft foundation design.

• Groundwater flow modelling by FEA to predict pumping rates of different permanent dewatering options.

• Subsequent DInSAR data validated the settlement predictions.