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Vl�oodwardrC - <br />� <br />a.o <br />SCOPE OF WORK <br />4.1 PROPOSED SCOPE OF WORK <br />Based on our understanding of the history of Brush Hollow Dam, and our experience <br />with over 100 "old dams", we have developed a detailed scope of work to complete the <br />investigation of the apparent slope movement and development of repair <br />recommendations. The purposc of the 5eld investigations will be to identify the <br />potential failure mode and slide surface within tha embankment/foundation. Stability <br />anaiyses will be performed using the results of the field investigations and laboratory test <br />results on samples abtained in the field. We will then deveiop recommendations for <br />embankment repairs based on the res f the investigations and analyses and our <br />extensive experience on simila� recommend the following detailed scope <br />�� <br />of work: � <br />����� <br />Task 1 - Test Holes/Pielo <br />�� <br />Our field investigations will consist of dri�lling test boles and installing piezometers and <br />movement monuments in the dam. We will locate the drill hales as described below, <br />based on a review of the records for Brush Hollow Dam and our field reconnaissance. <br />We recommend drilling a miniinum of 5 test holes. One additional drill hole could be <br />added depending on conditions encouatered at the five drill hole locations described <br />below. T�vo holes will be drilled from the dam crest at the azea of the cracking. The <br />crest drill holes will be used to attempt to locate the slide plane within the dam and to <br />obtain samples af the embankment material for laboratory testing. Two drill holes will <br />be drilled from the upstrea.m slope at the same stations as the crest drill holes. The <br />purpose of the upstream drill holes will be to sample the upstream zone of the <br />embankment and to try to Iocate the potential slide plane. One drill hole will be located <br />at the downstream toe to provide further definition of the embankment and foundation <br />section and to investigate the potential for a slide plane within t6e downstream slope. <br />Surface signs and the occurrence of drawdown prior to identi5cation of cracking may <br />indicate upstream slope movement; huwever, the absence of movement in the crest may <br />Woodward-CIYde Consultants • <br />23360/PR0.4 12-0$-93(8:53am)�RPT 4' 1 <br />