Application of Magnetic and Geotechnical Methods for Archaeological Site Investigations

摘要

The overall objective of this research was to develop and use methods to measure and assess vehicle impacts on buried archaeological deposits. The need for this stems from the large number of archeological resources located on U.S. Department of Defense (DOD) sites where training includes vehicular activities. Specifically, the objectives of this research were to verify the quantitative relationship between soil compaction and changes in magnetic susceptibility, to develop a geotechnical model of subsurface compaction under a vehicle rut, to evaluate various compaction and deformation measurement methods in a controlled setting, to apply these measurements at the field scale, and to use magnetic modeling to interpret results. Multiple experiments were conducted, with each experiment building on the results of the previous ones. The first experiment was a core compaction test that verified the relationship between bulk density and magnetic susceptibility. Then a geotechnical model was developed, which provided a tool for estimating the compaction profile under a rut based on stress curves under footings with static loading. The accuracy and shortcomings of the geotechnical model were demonstrated in later tests. The first series of tests provided a detailed investigation of compaction of uniform soil within a large wooden box. These experiments were used to refine the measurement techniques, to verify the geotechnical model, and to develop a better understanding of the depth and distance that a surface impact could propagate into the subsurface.