Please use this identifier to cite or link to this item:
Title: Physical property and dynamic compressibility analysis of the Watching Hill Blast Range
Authors: Jackson, J. G. (John Guy)
Keywords: Soils--Testing
Soil consolidation test
Shock waves
Stress-strain relations (Soils)
Publisher: Soils and Pavements Laboratory (U.S.)
Series/Report no.: Technical Report; S-72-4
Abstract: Abstract: This study was concerned with the analysis of geologic, physical property, and dynamic and static soil compressibility test data obtained for the Watching Hill Blast Range at the Defence Research Establishment Suffield, Alberta, Canada. The site profile consists of a thick succession of glacial tills and lake deposits with the near surface deposit composed of thin interbedded layers of lacustrine silt, sand, and clay sediments. The problem posed was that of furnishing accurate profile information for ground shock calculations of explosive events and selecting stress-strain curves to represent the in situ response of each stratum in the profile to transient uniaxial strain loading and unloading. The primary purpose of the analyses was to determine if a simplified procedure could be developed whereby this could readily be done for any given location within the site for which a field boring log and conventional soil classification test data were available. It was possible to develop such a procedure; two example applications are given for demonstration purposes. In the process of developing this procedure, it was found that the Unified Soil Classification System was too broad to adequately classify the various fine-grained sediments found within the near-surface lacustrine deposit. It was possible, however, to establish an expanded grain size and plasticity based classification whereby all of the sediments, regardless of their elevation location within the deposit, could be sorted into one of six soil groups. The specific gravity, water content, and density data for each of the six soil groups revealed consistent patterns of variation with depth and/or elevation. Therefore, the calculated void ratios, porosities, saturations, and air void contents also exhibited characteristic profiles. Evidence was presented, however, to show that, due to geologic and climatic influences, these composition property profiles were quite site dependent. They were used as a basis for subdividing each of the six soil classification groups into five generalized profile zones within which all the soil strata of the given soil group were expected to have similar compressibility characteristics. As a result of laboratory loading history similarities, the available uniaxial strain (or compressibility) test data for each soil group could be further categorized according to loading rate. By studying the records of field stress measurements obtained during explosive events, a rough correlation was established between laboratory test loading rates and those expected at various depths and surface overpressure ranges. Finally, based on the analysis of 130 measured stress-strain relationships (120 of which were from undisturbed specimens), a set of curves was drawn to represent, as a function of loading rate, the in situ uniaxial strain response of each soil classification group-profile zone combination. These curves quantitatively define the compressibility of the various interbedded soil strata in the upper glacial lake deposit at Watching Hill.
Appears in Collections:Technical Report

Files in This Item:
File Description SizeFormat 
TR S-72-4.pdf68.48 MBAdobe PDFThumbnail