Soil-structure interaction analyses for Chestfield Tunnel, Kent

Advanced numerical analysis using finite element and finite difference meth ods provides a powerful tool in the design of highway structures. This appr oach of realistic soil-structural modelling gives a much better understandi ng of behaviour than 'subgrade modulus' methods. The rapidly increasing pow er of desktop computers in recent years has enabled these advanced techniqu es to be used more routinely as part of a cost-effective design approach. T his paper describes design analyses undertaken for the new Chestfield Tunne l in Kent. On the basis of the analyses, significant cost savings in the pe rmanent works were achieved. Use has been made, in the design, of recent re search into the behaviour of high plasticity clay backfill.