2015-01-16_PERMIT FILE - M2015001 (2)

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Tegre Corporation Job No. 3124JS057 An exception to this general stratigraphy was encountered in Boring B-6, where a layer of poorly graded sand was encountered between depths of about 18 and 23 feet. This sand layer was not encountered in any of the other borings. 4.4 Groundwater Groundwater was not encountered in the borings during drilling. The level of the groundwater table will fluctuate seasonally with variations in the amount of precipitation, evaporation, and surface water runoff. The observations made during this investigation must be interpreted carefully because they are short-term and do not constitute a groundwater study. 5.0 GEOTECHNICAL PROPERTIES&ANALYSIS 5.1 Field Tests Penetration tests were performed in general accordance with ASTM test methods D1586 and D3550 to assist in evaluating the relative density/consistency of the soil. The N-values in the lean clay ranged from 19 blows per foot (bpf) to 50 blows per 8 inches. The R-values in the lean clay ranged from 35 bpf to 50 blows per 6 inches. The penetration tests indicate that the clay has very stiff to hard consistency. Only one penetration test was performed in the cobble and boulder layer because that material was very dense and we were unable to advance the augers more than about a foot into this material. An R-value of 50 blows per 8 inches was recorded in the cobble and boulder layer. 5.2 Laboratory Tests Laboratory tests were performed to assist in evaluating the engineering properties of the soil. Tests indicate that the lean clay is very stiff to hard, with hand penetrometer values typically in excess of 4.5 tons per square foot (tsf) and unconfined compression values ranging between 4,200 and 6,000 pounds per square foot (psf). Tests indicate that the clay is moderately plastic, with liquid limits ranging between 31 and 36 percent, and plasticity indices ranging between 20 and 23. The dry density of the clay ranged from 105 to 116 pounds per cubic foot (pcf). 5