Froude Scaling of Buried Structures Using Coal and Coal/Leas as Simulants for Sand. Volume 1. Study Results

Abstract : This technical report is divided into two volumes. Volume I presents the results of the study, while Volume II contains the Appendices. This study describes the development of the Froude scaling relationships between the various parameters or the general problems of both dynamic and static loadings. The results of laboratory tests on potential simulant materials are presented. The rationale for the selection of crushed coal and a mixture of crushed coal and lead shot as simulants for sand is presented and the results of a crushed coal/cement/water mix as a simulant for concrete. Results of proof-of-principle static tests of cone penetrometers being pushed into sand and the crushed coal and crushed coal/lead shot simulants are presented. Stress at the tip of the penetrator as a function of depth is presented for the full scale test in sand, the approximate 1/5 scale test in coal, and the approximate 1/10 scale test in the coal/lead mixture. The response of buried structures to the explosive affects of conventional weapons is often determined by testing scale models instead of actual full size structures. The size and material properties of the scale model structures are determined based upon scaling laws. Most scale models are based upon the Replica scaling law that reduces the linear dimensions of the structure while maintaining the same material properties.