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Ransom Tunnel Bulkhead Page 2 May 7, 1997 <br /> the open fractures carries water at times, probably during the <br /> spring runoff. The strike of the fracture is roughly parallel to <br /> the topographic contours . <br /> The recommended location at 319 feet from the portal was <br /> selected based on the competency of the rock present, second best, <br /> and sufficient depth to eliminate the potential for hydrofracturing <br /> if subjected to the maximum possible pressure head of 275 feet. <br /> Slightly better rock conditions are present at 446 feet from the <br /> portal . The reasonably competent rock present 293 feet from the <br /> portal is only 93 feet below the ground surface, not sufficient to <br /> eliminate the possibility of hydrofracturing of the adjacent rock <br /> and possible release of impounded water. This nearest to the <br /> portal bulkhead site is adjacent to major jointing. <br /> The Ransom Tunnel turns approximately 200 to the west <br /> approximately 550 feet from the portal . This limits the line of <br /> sight potential water potentially accelerated by the maximum <br /> credible earthquake acceleration of 0 . 087 ft/sec2. The design <br /> calculations demonstrate that earthquake acceleration does not <br /> control bulkhead design. <br /> The bulkhead design presented meets all design requirements, <br /> as shown on the calculation sheets . <br /> J'.0-L 5 ' <br /> J <br /> John F. Abel, Jr. <br /> Colorado P.E. 5642 <br /> 2 <br />