Persevere Engineering Solutions Ltd.

Ian Coker was contracted by the UK's DFID in Bolivia 1997-8, as mentioned above and was based at the University of San Simon in Cochabamba, Bolivia. One aspect of the project required measuring the "shear strength" of soils in order to calculate the likelihood of landslides occurring on steep slopes. This work involved managing the design, construction and testing of a novel kind of soil sampler, which was called the 'Nail Cage Soil Sampler'. This had a very simple but effective design. It comprised of a box-section surface plate and 20 large "nails" (12" long by dia 1/2").The nails were hammered into the soil through holes in the plate and thereby isolated a volume of soil,

which could then be removed intact. It worked very well indeed. This work has been published on the Internet by the Electronic Journal of Geotechnical Engineering. (see http://www.ejge.com then click on the Vol 5, year 2000 papers "A Device for Extracting Large Intact Soil Samples" by Ian Coker and Roger Flores. This paper includes a series of colour photographs.