Transcription
A Winding Road: Building aSustainable Sanitary SewerStream Crossing in EmergencyConditionsAPWA Mid-Atlantic ConferenceVirginia Beach, VAMay 10, 2013
OutlineBackground Site Conditions Immediate Response Temporary Solution Permanent Solution Construction Questions
Background – LocationDCFairfaxCountyAlexandria
Tropical Storm LeeFairfaxCountyDCAlexandria
Tropical Storm Lee The HolmesRun Crossing saw 8-10inches of rain Parts of Fairfax County received over5 inches of rain in 5 hours Rainfall equated to 500-1000 yearstorms in parts of Fairfax County
OutlineBackground Site Conditions Immediate Response Temporary Solution Permanent Solution Construction Questions
Before LeeNeighboringUtility SewerFairfaxCountySewer
After dSewer
Site Conditions (After Lee)County 36”EncasedConcreteSewerWeir ApronLow Flow weirCut into DamConcrete Damwith Z-pile
Apron Void
Causes for Damaged Pipe Large highintensity flows in HolmesRun Scour caused by high flows Earthquake?
OutlineBackground Site Conditions Immediate Response Temporary Solution Permanent Solution Construction Questions
Immediate Response By passpumping in place within 48hours of discovery of the break Emergency Contractors Adjustment of weir boards in anupstream flow structure Working with neighboring agencies tocoordinate pumps and response
Pumps Silent pumps to limit disturbance to surroundingcommunity24 pump monitoring to prevent overflowsHigh Cost
OutlineBackground Site Conditions Immediate Response Temporary Solution Permanent Solution Construction Questions
Temporary Solution On landconnection to the adjacenttrunk sewer The connection is suitable dryweather and smaller wet weatherstorms Allowed for time to design a long termsolution
Connection to Adjacent SewerNeighboringUtility SewerFairfaxCounty SewerNew SewerDamagedSewer
Temporary Structure Features Canal Gate PipeSlope
OutlineBackground Site Conditions Immediate Response Temporary Solution Permanent Solution Construction Questions
Permanent Solution Drop Manhole Micropiles Structural Steel Protecto 401 StreamBank Protection Stream Restoration
Permanent Crossing OverviewNeighboringUtility SewerFairfaxCounty SewerNew SewerNew Manhole
Drop Manhole Lowers the elevation ofthe pipe in the streamAllows for better pipeprotection and armoring
Micropiles 14 micropiles in 7 pairsCore reinforcement,steel casing, groutDrilled intodisintegrated rockDrilled and not driven toprotect the weir andstream
Structural Steel Gussett PlateLacingTransversal beamLongitudinal BeamsCradle Stiffener PlateBents
Pipe and Protecto 401 36”Diameter Ductile Iron Pipe Protecto 401 Liner Selected
Stream Bank Restoration Coir Block Soil Lifts at Construction entrances
Stream Restoration Upstream and Downstream of the Weir ApronReinforced Bed MixtureStream Base FillImbricated Rock
Stream Restoration Downstream
Low Flow Weir Cut Out
OutlineBackground Site Conditions Immediate Response Temporary Solution Permanent Solution Construction Questions
Construction PortaDam Goose
Porta Dam
Porta Dam
Porta Dam
Dry Site
Dry Site
Goose on Site
OutlineBackground Site Conditions Immediate Response Temporary Solution Permanent Solution Construction Questions
Acknowledgements Jonathan OkaforJonathan.okafor@fairfaxcounty.govThomas J. RussellThomas.russell@fairfaxcounty.govSam ShaikhSam.shaikh@fairfaxcounty.govBrendan SchilloBrendan.schillo@fairfaxcounty.govKen Eyrekeyre@greeley-hansen.comGary Ferrantegferrante@greeley-hansen.comEd Gerulategerulat@greeley-hansen.com Mike Pekkalampekkala@greeley-hansen.com Clyde Wilbercw@clydewilberllc.comCarlos Englertcenglert@schnabel-eng.comQamar Kazmiqkazmi@schnabel-eng.comMohammad Nasimmnasim@schnabel-eng.com
Questions
Fairfax County Sewer Damaged Sewer . Site Conditions (After Lee) County 36” Encased Concrete Sewer Concrete Dam with Z-pi
