The 100 year water surface elevation is 552.47 at the South Pedestrian Bridge. The landings really need to stay where they are at (555.50). We need to further discuss this at our meeting on Thursday. ________________________________ From: Christiansen, Eric [mailto:echristiansen@halff.com] Sent: Tuesday, April 13, 2010 2:33 PM To: Bruce Dunne Cc: Barnett, Clay Subject: RE: South Pedestrian Bridge Importance: High Bruce, After reviewing our calculations, it appears that we should be able to reduce our request for raising the landings. Previously, we were using the 100-year WSEL that Viewtech indicated on their drawings dated this past January. Of course, we've been told that those drawings were erroneous. Now, using the drawings from June of 2009, we see that this value should be 552.00'. If we add the structure depth of 2.67', that shows the landing must be at 554.67' with no freeboard. Since the current landing drawing shows them to be at an elevation of 555.50', we actually have 0.83' of freeboard with no adjustment whatsoever. Halff has requested Contech to try and shallow up the pedestrian truss by 6"-8". If we can get the landings raised by a similar amount (6"-8"), we could theoretically reach the 2' of freeboard we're trying to attain. Please respond by letting us know how much the landings could be raised. Thanks, Eric Eric S. Christiansen, P.E., SECB, LEED AP Senior Structural Engineer HALFF ASSOCIATES, INC. 1201 North Bowser Road Richardson, Texas 75081 Phone 214-346-6284 Fax 214-739-0095 Cell 972-955-2996 www.halff.com From: Bruce Dunne [mailto:bdunne@icon-engineers.com] Sent: Friday, April 09, 2010 3:31 PM To: Christiansen, Eric Cc: Barnett, Clay Subject: South Pedestrian Bridge Eric – you need to look at other options than this 32” deep bridge structure you are currently proposing for the pedestrian bridge. It will not work with what has currently been constructed. BRUCE F. DUNNE, P.E. President icon Consulting Engineers, Inc. Bicentennial Financial Center 250 W. Southlake Blvd., Suite 117 Southlake, Texas 76092 Phone: (817) 552-6210 Fax: (817) 552-3126 Mobile: (817) 707-9711