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slope and on both sides of the road at the drainage crossing, Figure 1). Photos of the road and <br />retaining walls are presented in Figures 2 through 9. <br />Retaining Wall <br />As shown in the photos, the retaining walls consist of timber retaining structures consisting of <br />vertical logs embedded an unknown depth into earth, horizontal logs placed, in some cases, <br />against the vertical members to retain fill materials placed behind the wall, and, in some <br />instances, horizontal members situated at approximate right angles to the wall face to provide <br />additional resistance to earth pressures. Some horizontal members are strewn over the hill side <br />providing little or no earth retainment; others are lashed to the vertical members on the <br />downstream side of the wall via steel cable. In some instances, the steel cable is being used to <br />retain vertical (and some cases) horizontal members. In one instance, the cable is anchored to an <br />upslope vertical member (Figure 8); in other instances, to what the cable is anchored to is not <br />known. Vertical members on cut -fill portion of the road are leaning downslope up to 20 degrees <br />from vertical. <br />Test Pits <br />As shown in Table 1, our test pits encountered a dark brown gravelly, clayey sand fill, 5 to 8 feet <br />thick. Hard, strong bedrock similar to the materials exposed in the cut slope was encountered <br />below the fill. This material was dense to an approximate depth of 12 inches, and relatively <br />loose below. The fill was dry to moist over the upper approximate 12 inches, and moist to wet <br />below. Occasional cobbles up to 14 inches in longest dimension were encountered in Test Pit #1 <br />and Test Pit #2, primarily near the bottom of the test pits near the fill/bedrock contact. Test Pit <br />#2 encountered bedrock at 5 feet below grade approximately 3 feet from the bottom of the <br />adjacent cut slope (shown as Test Pit #2a in Table 1) and at 8 feet, approximately 8 feet from the <br />bottom of the cut slope (Test Pit #2b in Table 1). Laboratory test results, summarized in Table 2, <br />indicate the Unified Soil Classification of the fill material is SC. <br />May 26"' Report <br />Density test were performed on the upper 6 inches of the roadway subgrade. Test results <br />indicated relative compaction values greater than 97 percent compaction per ASTM D698. <br />Atterberg limits results are similar to those obtained from this investigation. No conclusions <br />regarding roadway stability was contained in the May 26 report. <br />Conclusions <br />On the basis of our geotechnical reconnaissance, we conclude that the road can be used for the <br />purposes intended, provided the recommendations summarized in this report are incorporated <br />into the efforts to complete the road. The road appears to be in relatively good condition. Minor <br />cracking was observed at cut fill transitions; however, no slumps or severe depressions were <br />observed in the road. The cut slopes in the through -cut section are performing well. The cut <br />slopes in the cut -fill section are steep but the rock is generally strong and hard and the rock <br />May 30, 2010 <br />