Field instrumentation and monitoring were carried out to establish the behaviour of a T-shaped diaphragm wall founded in over-consolidated clay during its construction as part of the Aldershot Road underpass on the A331 Blackwater Valley Route. Measurements of ground movements, wall movements and bending moments, temporary and permanent prop loads, and heave pressures and porewater pressures below the carriageway slab were continued until two years after its opening to traffic in 1996. After a period in which no measurements were made, monitoring of underpass performance was resumed in 2002 as part of the principal inspection of the structure, which was due six years after its construction. The scope of this report is primarily to report and discuss the more recent findings, although in many cases the data from the start of construction are included to help identify seasonal trends. (Author/publisher)
Abstract