ABSTRACT
New Zealand experienced several large earthquakes which damaged residential and commercial properties. For post disaster recovery, solutions were sought to rebuild on land prone to seismically induced liquefaction and lateral spreading. Engineering guidance in NZ introduced the basal geogrid reinforced gravel crust concept to allow construction of lightweight timber framed buildings on liquefaction prone ground. This paper describes the design and construction aspects for multiple layers of geogrids. It provides the detailed concepts behind the reinforced crust approach, including case studies of structures surviving repeated seismic shaking without major damage. The paper then describes several case studies of completed projects. It focuses on construction details that are considered essential for successful application of a reinforced crust subject to strong seismic shaking. Lastly, the paper provides releveling and repairability considerations to ensure that buildings can be returned to full functionality by relevelling after a major event.
