Laserfiche WebLink
<br />solLS DAre <br />Soil laboratory testing was performed by Advanced Terra Testing o Denver. <br />Two soils samples were obtained from the embankment construction ea, one <br />being an extreme of the soils being utilized. One soil was a low lasticity <br />clay (CL) while the other was a low graded silty sandy material ( -SK). <br />Standard proctor tests were run on each of these soil extremes and copies of <br />the soils tests are attached. To summarize, the silty sand has a aximum dry <br />density of about 133 pounds per cubic foot and optimum moisture c tent of 7.8 <br />percent, while the lean clay had a maximum dry density of 110 poun s per cubic <br />foot and an optimum moisture content of about 19.4 percent. For p actical <br />purposes, the largest proportion of the berm was a blend of these wo <br />materials that exhibited characteristics closer to the silty sand hen to the <br />lean clay. <br />Laboratory tests enabled field compaction tests to be conducted. st of the <br />testa were conducted in the field Dy Fox Consultants. A copy of t air Eield <br />summary is attached. Essentially, the entire berm was compacted t 95 percent <br />of standard proctor density or greater. One small area near the u stream <br />limit of the berm was difficult to compact, and a layer of geotext le was used <br />to stabilize the material. Compaction efforts were continued abov the filter <br />fabric and 95 percent densities were achieved. <br />• COICLILSIOY , <br />We believe the embankment ie stable end safe. The "Design of Smal Dams" <br />guidelines are quite conservative, as shown by the results of the tability <br />analyses. A short live homogeneous dam of this type is likely to xhibit a <br />moderate amount of seepage through the embankment, but is not like y that the <br />seepage would endanger the dam. The 3:1 elopes, one foot freeboar and two <br />Foot flood control that are called for are conservative, safe engi eating <br />practices. <br />U <br />- 2 - <br />