08-08-2007 Council Agenda - Laserfiche WebLink

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It should again he emphasized that the depths of unsuitable soil given above are a preliminary estimate based upon random split- barrel sampling tests. A small amount of additional estimated excavation depth should be added to that given in the logs and Table I, Analysis of Soil Borings, to conservatively allow for variations in the soil profile and for inadvertent over excavations, which are impossible to avoid, when using power machinery. Please see Boring Logs for the soil type and color at the base excavation as indicated in TABLE I. The bottom of the excavations should be compacted with a mechanical vibrating compactor prior to placing footings or engineered fill. If site correction occurs during winter, the base of excavation should be adequately protected from freezing. Recommendations appears on the standard data sheet at the end of this report entitled "Freezing Weather Effects on Building Construction." Excavated organic material, uncontrolled fill, wet unstable soil or other soil contaminated with topsoil, vegetation, etc, should be disposed of offsite, or in landscaping areas, where the bearing of weight will not be required. B. Fill Placement Fill material, as required, should be mineral soil, free of debris, boulders and organic material, of such suitable moisture content that it can be readily compacted to specified levels. Fill should be placed and compacted in a manner that will allow completed compaction of the total fill layer to 95% of standard maximum density according to ASTM D 698. Frozen material should not be used in fill construction, nor should any part of the completed fill be allowed to freeze. Due to the presence of organic soil, vegetation, etc, there appears to be no opportunity to salvage existing fill for re -use as controlled fill. A soil compaction test should be conducted for every two feet of till in appropriate segments of the area. Building adjacent to wetland. Please see the enclosed detail "Oversize for Swamp or Extremely Soft Soil Conditions ". Oversize for Swamp or Extremely Soft Soil Conditions" the top of fill should extend horizontally a distance 5 feet beyond the structure pad or footing limits. The fill surface may extend downward and outward on a 2:1 slope to competent soil. It is upon this formula that required laterial excavation oversizing should be base. C. Inspection and Testing The Client should retain a geotechnical engineering firm to inspect excavations, make field judgments as to subsoil adequacy, and to carry out a program of field and laboratory testing of engineered fill. This firm shall be responsibility for knowledge of contents of this report and for proper interpretation and correlation of data. - 1 1 - 4