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I I AET #93-1379 - Page 8 ,. Review of Soil Prooerties I . Strength/Stability - Opinions relative to subgrade strength and stability have been generally discussed in the previous Site Conditions section which describes the soil I encountered at each individual street location. Generally, much of the soil subgrade appears to be reasonably stable with more obvious exceptions within the upper 3' zone I noted at Boring #4, #5, and #8. Conditions at Boring #6 are also somewhat unstable, - although sample review suggests the condition is not a severe as the other described I locations. Please note that soil conditions encountered are mixed and variable, and we I expect stability properties will also be variable along the roadways such that some local or "spotty" zones of instability will exist. I . Compressibility - Without a significant grade increase, and assuming upper soils are .. corrected as needed for strength reasons, compressibility of the subgrade soils will not be a problem at this site. I . Drainage Properties - Most of the subgrade soils are clayey, which are relatively poor I draining materials. These soils can allow for perching or trapping of water within the base and sub grade. The main exceptions to the above are as follows: I - The silty sand layer within the upper 3' along Keithson Drive meet the I requirements of a granular borrow. These soils are judged to be moderately fast to moderate draining. I The sand layer noted from 3' to 4' deep at Boring #12 is a silty sand which is also - I at least moderately draining. This particular layer was found to include trapped water, which resulted in a measurable water level within the borehole. I i' I