CCP 01-31-1994 - Laserfiche WebLink

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-- I AET #93-1379 - Page 5 J It is important to note that the subsurface conditions only indicate the material classification/properties at I the sampled locations and variations do occur between and beyond borings. I Keithson Drive (Borings #1-3) I The borings indicate bituminous thicknesses ranging from 2]12" to 3". Underlying base is mostly crushed limestone with thicknesses ranging from 5" to 7'12". The roadway also includes a silty I sand layer (granular borrow) which extends to about 3' beneath the top of the road surface. Soils below this depth are sandy lean clay and clayey sand fill soils. Although N-values are not I overly high in portions of the sub grade, and moisture contents are likely a little over the "optimum moisture content level," we do judge that none of these soils are excessively unstable I such that they should directly lead to significant pavement problems. Please note that Boring #2 was specifically placed within an obvious east/west sag within the I pavement. It appears these sags may be associated with utility/service backfill, and the boring . was specifically placed for comparison to the two remaining borings (which were not placed in sag areas). Because of the potential for buried utilities, this boring was only extended to 4', I although it did allow us to compare profiles with the other two borings. Our review of these borings suggest no significant differences are present in the sag area versus the remainder of the I roadway. I Amble Drive (Borings #4-7) The borings indicate quite variable pavement thicknesses ranging from 2',4" to 7". The borings I suggest the lack of a base layer, although Borings #5 and #6 suggest an oiled sand layer below the rather thin bituminous, which could potentially be a poor quality/weathered bituminous. I Sub grade soils vary from lean clay with sand glacial till to cohesive mixed fill soils. Stability of the clays appears to be variable, based on the wet and soft condition of some of the samples. I Poorest subgrade conditions appear on the north end and transitionally tend to improve to the south, where the soils at Boring #7 are more stable. ~ I