Design of a contiguous bored pile wall to reduce lateral spreading potential; force based and displacement based approaches

Liquefaction induced lateral spreading associated with the Canterbury earthquakes of 2010 and 2011 has resulted in significant damage to numerous riverside properties in Christchurch. A number of methods for mitigating lateral spreading risk exist; these often involve ground improvement adjacent to the free face.

Preliminary design using a contiguous bored pile wall to retain liquefied soil and reduce the magnitude of seismically induced lateral spreading has been carried out for a site in Christchurch. Both force based and displacement based design methods have been used for this design. A summary of each method is presented, followed by discussion of the relative merits of each approach and parameter sensitivity.