The damage to Christchurch’s lifelines has been observed widely across the region as a result of the Canterbury earthquake sequence. In order to incorporate earthquake resilience into
infrastructure repair and design, a cost effective and non-intrusive method of liquefaction mitigation is required. Commonly applied methods of ground improvement to mitigate liquefaction are best suited to coarse grained soils, are intrusive and they may require dewatering and a large green-field site to be cost effective.
The purpose of this paper is to review two emerging methods of ground improvement to mitigate liquefaction-induced land deformation using passive site remediation. Emerging ground improvement methods that will be effective in fine grained soils and can be applied with minimal disturbance to existing structures have a potential to provide significant environmental and cost savings in the future.
Two of the most promising emerging methods of ground improvement are passive site remediation using colloidal silica and microbial-induced calcite precipitation (MICP). Several studies have indicated that colloidal silica treated sands have shown significantly increased resistance to cyclic loading. The primary focus of biological engineering research to date,
MICP has been shown to increase resistance to liquefaction of loose sand. Successful field trials have been carried out for both methods.