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Enhancement of Hesco Bastion wall models to better predict magnitudes of response under far field loading conditions
journal contribution
posted on 2017-12-14, 13:17 authored by H Dirlewanger, D Pope, D Russell, F Landmann, C Haberacker, Andrew BarrAndrew Barr, Andrew TyasAndrew Tyas, A StolzPaper presented at the 17th International Symposium on the Interaction of the Effects of Munitions with Structures (ISIEMS 2017), in Bad Neuenahr, Germany.
Abstract
At the previous ISIEMS conference (2015), a UK-German initiative to generate validated models of Hesco-Bastion wall systems exposed to far-field loading was presented. Although the work produced models which very convincingly recreated the tipping and sliding modes of response, transient diagnostics revealed that the rates of deformation and the thresholds of wall instability were not faithfully predicted. During a subsequent series of wall trials in Germany (extending into 2017), the “in situ” condition of the wall’s fill material was investigated prior to blast testing and the extracted soil properties compared to those measured under laboratory conditions. This exercise revealed that the lower portion of the wall fill was considerably more saturated than had previously been assumed. When soil properties commensurate with this state were integrated into the simulations, a more faithful threshold for tipping was predicted. In addition to enhancements made to the modelling process and the aspiration to generate a quicker-running simulation technique, this paper describes the field measurement techniques used to assess the “in situ” water content together with the philosophy behind the resulting adjustments to the model geometry and material properties. The paper also describes the testing and blast response of other wall types and the improvements made to the general diagnostic process with respect to obtaining more comprehensive high quality model validation data and generally improving design and fabrication of field camp protection systems.
Abstract
At the previous ISIEMS conference (2015), a UK-German initiative to generate validated models of Hesco-Bastion wall systems exposed to far-field loading was presented. Although the work produced models which very convincingly recreated the tipping and sliding modes of response, transient diagnostics revealed that the rates of deformation and the thresholds of wall instability were not faithfully predicted. During a subsequent series of wall trials in Germany (extending into 2017), the “in situ” condition of the wall’s fill material was investigated prior to blast testing and the extracted soil properties compared to those measured under laboratory conditions. This exercise revealed that the lower portion of the wall fill was considerably more saturated than had previously been assumed. When soil properties commensurate with this state were integrated into the simulations, a more faithful threshold for tipping was predicted. In addition to enhancements made to the modelling process and the aspiration to generate a quicker-running simulation technique, this paper describes the field measurement techniques used to assess the “in situ” water content together with the philosophy behind the resulting adjustments to the model geometry and material properties. The paper also describes the testing and blast response of other wall types and the improvements made to the general diagnostic process with respect to obtaining more comprehensive high quality model validation data and generally improving design and fabrication of field camp protection systems.
