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~ SECTIOMTHREE Back9round Information 3.7.1 Physical and Index Properties Testing The embankment clay samples generally classified as moderated to highly plastic, sandy, silty clay (CL, CH). The measured dry unit weight ranged from 94.7 to 103.8 pounds per cubic foot (pc fl at moisture contents ranging from 18.2 to 28.2%. The average dry unit weight was 98.9 pcf and the average moisture content was 23.6%. The specific gravity of a sample from boring DH4 at a depth of 5 feet was 2.65. The gradation results for the embankment clay show the fines content ranged from 64.3 to 89.2% for an average of 81.2%. Liquid limits (LL) ranged from 41 to 56 for an average of 52 while the plasticity index (PI) ranged from 28~ to 42 for an average of 47: Test results performed for the 2003 Study related to the embankment clay were generally similar to current results. The clay had measured dry unit weights ranged frorn 79 to 116 pcf, with an average of 1 O 1 pcf. The moisture contents averaged to 19.1 %, with a range from 14.2 to 29.0%. The fines content ranged from 61 to 92% for an average of 80%. The LL ranged from 33 to 53 and the PI ranged from 17 to 37. The average LL and PI was 47 and 29, respectively. The gravelly, silty, clayey poorly-graded sand (SP-SC) frorn boring DHI near 20 feet had a dry unit weight of 142.0 pcf with a water content of 12.7% and a fines content of 8.0%. The gravel content was not measured but was estimated in the field to be less than 10%. Testing for Atterberg Iimits was not performed on the ciayey portion of the sampie. None of the 2003 Study borings were located in the immediate area of DH1. The nearest 2003 Study boring is BH-3, but the boring log shows shale was encountered at approximately at a depth of 9 feet and no gravelly sands above that depth. The weak clay zone (CL) found in borings DH3 and DH4 was tested as a composite sample. The composite sampie had an average dry unit weight of 81.8 pcf, an average water content of 15.0%, a fines content of 69.3%, and a specific gravity of 2.65. The LL was 43 and the PI was 27. The 2003 Study boring BH-1 was the nearest test hole to DH3 location; the 2003 Study hole was drilled to 16 feet below ground surface with a tested dry unit weight at that depth of 100 pcf. It appeared that the 2003 Study did not encounter this weak clay zone. The sample of foundation material tested from boring DH7 at 35 feet has a dry unit weight of 121.5 pcf, a water content of 14.1 %, fines content of 98.2%, a LL of 46, and a PI of 28. It ~S 3-8