SOIL TESTS FOR BOMB PENETRATION STUDY, HILL AFB, UTAH.
ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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The investigation described in this report was conducted to provide information concerning the physical properties of the soil in the impact area of a bomb cratering test conducted by the Air Force. The information contained herein is intended for use in relating depth of bomb penetration to shear strength of soil. The tests were conducted in the lacustrine deposits of Lake Bonneville, just west of the Great Salt Lake, Utah. Five undisturbed-soil-sample borings were made in close proximity to bomb penetrations, but were located in such a manner as to preclude disturbance of the soil by the bombs. Test results consist of a field determinations of natural density and water content of samples from borings 1 through 4, b laboratory determinations of natural density, water content, and shear strength of the soil from boring 5, and c laboratory determinations of Atterberg limits of samples from borings 1 through 5. Clays and silts of relatively high plasticity were encountered from the ground surface to an average depth of 35 ft. At the 35-ft depth, a thin stratum of clayey sand overlying silty clay was encountered. The physical properties divided the subsurface into three principal zones 0.5 ft, 5-35 ft, and 35-52 ft bottom of borings. Natural water content was very near the liquid limit below 5 ft, averaging 54 from 5 to 35 ft and 33 below 35 ft. Shear strength of the soil, which was determined from laboratory tests of unconfined compressive strength, averaged 740 psf between the depths of 5 and 33 ft below 33 ft, the shear strength averaged 892 psf. Author
- Soil Mechanics
- Aerial Bombs