Laboratory Pull-Out Test of a Percussion Driven Earth Anchor Installed in a Clayey Soil Compacted Inside a Soil Box

A PDEA, Duckbill model 88 II (DB-88 II), was selected and tested in a laboratory pull-out test in a silty lean clay conducted in a soil box measuring 1 m in length, 1 m in height, and 0.6 m in width. The sampled soil was compacted in a soil box at 95% compaction and 10.5% water content based on the standard compaction test results. The PDEA was installed by driving the installation rod with a hammer nearly the bottom of the box at 0.9 m. The PDEA was pulled upward using a hydraulic jack to measure the pull-out resistance of the anchor. The pull-out load, displacement, and soil surface movement were recorded with a load cell and LVDTs. A pull-out load-displacement curve was obtained and analyzed to determine the ultimate pull-out load from the test. A prediction equation by DAS 1980 was also used to estimate the pull-out capacity of the anchor embedded in the box. The comparison between the measured ultimate pull-out load and the estimated values from the equation indicated that there is a considerable discrepancy between the value estimated from the equation and that from the actual controlled pull-out test.