Behaviour of a cantilever contiguous bored pile wall in boulder clay at Finchley

For environmental reasons highways within built-up areas are increasingly being constructed below ground in retained cutting using bored pile or diaphragm wall techniques. Walls of this type can be constructed with high or low level props or anchors as methods of long term support: however the most basic form of construction is that of a cantilever wall which relies on base fixity in firm ground for its stability. This report describes the field instrumentation and monitoring carried out to establish the behaviour of a cantilever contiguous bored pile wall constructed as part of the A406 North Circular Road Improvement Scheme between East of Falloden Way and East of High Road, Finchley. Measurements of wall movement and bending moment together with movements in the adjoining ground were monitored during the various construction stages and for a period of about 10 months after completion of construction. (A)