Sign up to our Newsletter
Lankelma supports earthquake recovery investigations in Christchurch, New Zealand
Thursday, September 27th, 2012
A 20T 6×6 wheeled Cone Penetration Testing (CPT) truck and associated test apparatus from geotechnical specialist Lankelma is proving popular in Christchurch, New Zealand, where it is supporting the geotechnical community in refining its understanding of regional ground conditions.
The truck, which carried out its first investigation in May 2012, has since completed over 60 piezocone testing projects in the region. The work comes in the wake of the devastating February 2011 earthquake, which severely damaged Christchurch with widespread liquefaction of the underlying soils.
“There is an on-going need to establish well-understood and detailed ground models on which to develop future infrastructure,” explained Carlton Hall, Engineering Director at Lankelma, “and the keenness of the geotechnical community to engage with Lankelma and raise the bar on CPT data confidence has been very encouraging”.
“The CPT truck has proved popular with clients, not least because of its ability to push through near surface gravels using a casing system, before penetrating the potentially liquefiable materials below,” he said.
The truck is equipped with standard piezocone instrumentation which enables soil classification, the derivation of basic geotechnical parameters and an assessment of liquefaction potential. The unit can also be used to acquire 63mm undisturbed MOSTAP samples, deploy seismic cone apparatus to acquire shear wave velocity data with depth and install groundwater monitoring instrumentation. When combined with information on unit weight, the shear wave velocity data is used to develop the small-strain stiffness profile for the ground, and so provide designers with information contributing to the detailed design of geotechnical structures.
Lankelma is combining its broad international CPT experience in gathering high quality engineering data with local expertise, through its relationships with local ground investigation company, KGA Geotechnical Investigations Ltd and international drilling contractor Webster Drilling and Exploration Ltd.