Behaviour during construction of a propped contiguous bored pile wall in stiff clay at Rayleigh Weir

Field instrumentation has been installed to investigate the performance of a contiguous bored pile wall propped at carriageway level founded in over-consolidated clay, during and immediately after its construction to form part of an underpass at Rayleigh Weir, Essex. The construction sequence involved installation of bored piles followed by partial excavation, installation of temporary props, completion of excavation, construction of the permanent prop slab and removal of the temporary props. Measurements of ground movements, total lateral stresses and porewater pressures were made both during pile installation and underpass construction. The development of movements and bending moments in the wall, and loads in both the temporary props and permanent prop slab were monitored. (A)