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Proposal for Geotechnical Engineering Services <br />Norman Lutheran Church Riverbank Repair ■ Kindred, North Dakota <br />May 17, 2012 ■ Terracon Proposal No. PM1120117 <br /> <br />Reliable ■ Resourceful ■ Responsive 2 <br />Project Description <br />The church and 52nd Street Southeast are located along an outer curve in the Sheyenne River <br />about 3 miles northeast of Kindred. Based on the report you provided dated April 10, 2012, <br />erosion of the riverbank has caused slope failures along the outer edge of the channel and are <br />located presently less than 10 feet from the edge of the road. The proposed project would <br />involve the feasibility of stabilizing a section of the Sheyenne River near the Norman Lutheran <br />Church. <br /> <br />Three options were proposed by Houston Engineering in regards to stabilization of the <br />riverbank. Option 1 involves sheet pile approximately 78 feet long driven adjacent to the <br />existing river channel over a length of approximately 775 feet. This option would involve <br />minimal clearing of the riverbank, since the wall would be located between the edge of the road <br />and the top of the river channel. <br /> <br />Option 2 consists of driving sheet pile approximately 30 feet long over a similar length of 775 <br />lineal feet. This option would include shorter sheet pile, along with some minor reshaping of the <br />channel as well as clearing and grubbing. <br /> <br />Option 3 would consist of clearing and grubbing along the road, combined with reshaping the <br />channel slope and placing riprap along the entire project area to protect the riverbank from <br />further erosion. This option assumes a 2:1 (H:V) slope on the riverbank would be acceptable. <br /> <br />Most of the riverbanks in the Red River Valley would be considered only marginally stable with <br />estimated factors of safety of less than 1¼ within close proximity to the top of channel. For a <br />successful repair alternative, we would recommend a minimum long-term factor of safety of 1.5. <br />Based on our past experience in this area, obtaining a minimum factor of safety of 1.5 for <br />roadways located within 10 feet of the top of the channel may not be economically feasible. <br />Also, in areas with correct slope failures, we have observed increased movement after removal <br />of trees and other vegetation. <br /> <br />Should any of the above information or assumptions be inconsistent with the planned construction, <br />please let us know so that we may make any necessary modifications to this proposal. <br /> <br />B. SCOPE OF SERVICES <br /> <br />The services to be provided by Midwest Testing/Terracon are summarized in the following <br />paragraphs. <br /> <br />Field Program – Based on an overall repair length on the order of 775 feet, we propose three soil <br />test borings along the edge of the existing roadway. Our past experience in the Kindred area