Laserfiche WebLink
, � <br /> Mr. Robert Owens <br /> GME Project No. 3766 2 October 19 , 1992 <br /> Results <br /> On October 8 , 1992 , the writer and an Engineering Technician obtained <br /> elevations along three survey lines extending from the existing house <br /> perpendicular to the slope and ending at the edge of Lake Minnetonka. <br /> Line 1 was established approximately 20 feet south of the north edge of <br /> the house; Line 2 was established approximately 50 feet south of the <br /> north edge of the house; and Line 3 was established approximately 75 <br /> feet south of the north edge of the house. Attached are the cross <br /> sections based on these elevations. Line 2 was established through the <br /> existing failed zone within the slope. <br /> As can be seen from the attached cross sections, the slope is divided <br /> into approximately two portions. An upper zone having a sideslope of <br /> approximately 1. 1 to 1. 5 horizontal: l vertical; and a lower zone having <br /> a flatter slope of approximately 2 to 3 horizontal: l vertical. Based <br /> on the preliminary data, it is our opinion that it is the upper steeper <br /> zone that is marginally stable. <br /> Based on our engineering assessment of the cross sections, we submit <br /> three possible remedial schemes: <br /> 1. Reshape the entire slope to form a <br /> flatter, more stable configuration <br /> 2 . Construct a double retaining wall <br /> eliminating the existing sideslope <br /> 3 . Combination slope with reshaping and a <br /> single retaining wall <br /> We have included preliminary drawings outlining these possible remedial <br /> measures. After discussing these with you, we understand that <br /> reshaping the entire slope is undesirable since this would require <br /> losing a large amount of ground and trees. If one of the two remaining <br /> schemes is chosen for slope repair, it is important that the existing <br /> fill soil be removed and replaced in a properly compacted condition. <br /> The natural soils should be benched, and the fill placed and compacted <br /> in horizontal lifts, thereby eliminating the creation of a potential <br /> failure surface between the fill and natural soils. In addition, the <br /> use of a geotextile behind the wall would be beneficial for <br /> stabilization. It should be noted that alternate 3 would be less <br /> costly than alternate 2 , since a rough budget estimated cost for tied <br /> back timber retaining walls is about $10 per square foot of wall. <br />