ABSTRACT
The new Wembley Stadium’s main architectural feature is an iconic 133 m high triumphal arch. The arch was constructed at an angle of 1.63° to the horizontal. This was chosen as a compromise between minimising the force initially imposed on the arch and the practical difficulties of fabricating the arch the site ground surface. Trigger levels were specified for the arch and all the pile group foundations, which, if breached, required the implementation of contingency measures to maintain an acceptable level of safety. Precise surveys of the pile caps commenced about three months before commencement of arch raising. The arch raising was completed as originally planned. The application of the observational method through progressive modification enabled risks to be minimized during arch raising. It was possible to demonstrate that the risk of damage to the arch and the arch foundations was kept as low as reasonably practical.
