Construction Today - January 2010 - (Page 100)
Civil | NICHOLSON CONSTRUCTION CO. Finding New Methods T AN AUXILIARY SPILLWAY FOR CANTON LAKE DAM IN OKLAHOMA USES INNOVATIVE BUILDING TECHNIQUES. he Canton Dam Auxiliary Spillway Channel Excavation Project Phase One involves upgrading the existing dam to meet revised probable maximum flood (PMF) criterion. In 2001, the U.S. Army Corps of Engineers determined that the spillway capacity of 339,000 cubic feet per second (cfs) for the 61-year-old gated structure, which was completed in 1948, was inadequate for revised PMF flows of 626,000 cfs. The Corps’ solution was to construct a new 2,100-foot-long auxiliary spillway channel on the right abutment of the dam to provide the additional discharge capacity required for a PMF event. The new spillway structure will utilize a system of fuse gates designed to topple in a controlled manner when a flood of a certain magnitude occurs. Unlike tainter gates, which open and close using electromechanical mechanisms, fuse gates need to be rebuilt once the flood event passes. However, whereas tainter gates require continual maintenance to maintain the integrity of seals and operability, fuse gates provide a reliable means for passing a flood while remaining relatively maintenance-free over the design life of the structure. At initial glance, it may seem that rebuilding a fuse gate would be a costly endeavor. However, one of the advantages of a fuse gate system lies in the statistical probability of how often a PMF event occurs. It could be many years before such an event might occur. Construction »Nicholsonown sand for the made its Canton Lake Dam project. Nicholson Construction Co. www.nicholsonconstruction.com • Headquarters: Cuddy, Pa. • Service: Geotechnical contracting Unique Construction Method The fuse gate system is situated near the upstream portion of the spillway between 45foot-high by two-foot-thick reinforced concrete walls. One of the unique aspects of the Canton Project was the method used for constructing the reinforced concrete walls, also known in the geotechnical industry as diaphragm walls (d-walls) or slurry walls. Dwalls are a top-down construction method. They are essentially a trench excavated in a series of panels under a polymer (or bentonite) slurry designed to stabilize the trench walls during the excavation process. Once a panel is excavated, a reinforcing steel cage is inserted into the trench immediately followed by placement of the structural con- “The unique thing about Oklahoma is that there’s a lot of sand; it’s just not the right sand.” –Paul Krumm, project manager crete. A high slump concrete mix is tremied to the bottom of the trench panel through 10inch diameter pipes. While the trench is being slowly back-filled, the displaced polymer slurry is recaptured for use to excavate the next panel. The diaphragm wall construction method was selected for the Canton Project because it reduced the extent of additional excavation necessary for constructing a conventional reinforced concrete wall, wherein appropriate side sloping is required for trench stability and safety. The auxiliary spillway channel entails two 730-foot-long d-walls extending from the existing ground surface at an elevation above sea level of ~EL. 1647 to a bottom toe elevation of ~ EL. 1585. The d-walls are toed-in about 18 feet below the final channel excavation of ~EL. 1603. Construction of the d-walls started May 1, 2009, and was completed Sept. 15, 2009. A total of 6,850 cubic yards of concrete and 500 tons of steel was placed for 79,000 square feet of wall area. As the channel area between the d-walls is excavated, approximately 200 tieback anchors will be installed at two levels. The Cut-off Wall Immediately downstream of the diaphragm walls, a 670-foot-long cut-off wall was installed extending from the south diaphragm wall to the north diaphragm wall. The purpose of the cut-off wall is to stop erosion of the spillway channel during a flood event from migrating upstream and comprising the fuse gate structure and channel d-walls. CONSTRUCTION-TODAY.COM JANUARY 2010
Table of Contents for the Digital Edition of Construction Today - January 2010
Construction Today - January 2010
Metrus Construction Limited: Le Parc Tower II
CJ Pink Ltd.
Costello Dismantling Co. Inc.
Allied Building Products Corp.
IDEURBAN: The St. Regis Mexico City
Jersen Construction Group
Killian Construction Co.: The Westin Hotel
Legacy Partners Residential: Riverpark
Strathcona Mechanical Ltd.
Tilton Pacific Construction Inc.
On the Cover
Product Showcase: Software and New Technology
Nicholson Construction Co.
Gilchrist Construction Co.
Turner Construction Co.: MIC Rental Car Center
Union Concrete Construction: Outer Harbor Parkway Project
D’Onofrio General Contractors Corp.
Worldwide Rental Services
AmQuip Crane Corp.
EIC Associates Inc.
Intercounty Paving Associates LLC: N.Y. Route 112
Matrix Design Group
Nicholson Construction Co.: Canton Dam
Wilson & Company Inc. Engineers and Architects: Rail Division
Group Lepine Ltd.
Laurysen Kitchens Ltd.
Aspen Ridge Homes: Vu Living
Walsh Construction: Sherman Replacement Hospital
PortSide Builders Inc.
Summit Builders Construction Co.: Classic Residence at Silverstone
Keystone Construction Corp.: Carmel Arts District Lofts
HDR Architecture Inc.
Brasfield & Gorrie LLC
Dimeo Construction Co.
EllisDon: North Park Quad Pad Arena
CANA Construction: TELUS World of Science
Cornerstone General Contractors Inc.
Harvey-Cleary Builders: City of Austin Public Safety Training Facility
Hensel Phelps Construction Co.: Granada Hills High School
Pirtle Construction Co.: City of Miami College
Sundt: East Contra Costa
Taylor & Parrish Inc.: Carole Weinstein International Center
Turner Construction Co.: Nationwide Children's Hospital
Turner Construction Co.: Duval Unified County Courthouse Facility
Weddle Brothers Construction Co. Inc.
AP Construction Inc.: Kensington Creative and Performing Arts High School
The Boldt Co.: Luther Midelfort Hospital Expansion
Choate Construction: NGCSU Projects
Donley’s LLC: Bavaro Hall at the University of Virginia
EllisDon: Woodstock General Hospital
McCarty Corp.: Maneuver Center of Excellence Headquarters
Munlake Contractors Inc.
Murray Company: Kiowa Country Memorial Hospital
River City Construction LLC
Skyline Roofing Ltd.
SpawGlass: Austin Community College Round Rock Campus
W.E. O’Neil Construction: Downtown Women's Center Project
CANA Construction: SMART Technologies
Ecco III Enterprises Inc.
G.W. Peoples Contracting Co.
ARCO/Murray National Construction Co. Inc.
Baker Electric Inc.
Chester Bross Construction Co.
Titan Wrecking & Environmental LLC
Last Look: Urban Landmarks
Construction Today - January 2010