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Cost Effective Drainage Structures. Henry J. “Hank” Gottschalk, III Technical Resources Engineer Virginia Concrete Conference March 2010. Financial Assessment of Drainage Structure. Cost of supply. Bridge Systems. Culverts. Pipes. Drainage Inlets.
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Cost Effective Drainage Structures Henry J. “Hank” Gottschalk, III Technical Resources Engineer Virginia Concrete Conference March 2010
Financial Assessment of Drainage Structure • Cost of supply
Conduit Structure Horizontal Structures
Purpose of vertical structure • Connect pipes
Purpose of vertical structure • Connect pipes • Provide access
Purpose of vertical structure • Connect pipes • Provide access ASCE Photo Contest
Purpose of vertical structure • Connect pipes • Provide access
As = 0.0025 x D(in) Round Vertical Structure
Financial Assessment of Drainage Structure • Cost of supply • Cost of proper installation & inspection
Highway Congestion • Congestion robs our nation of productivity and quality of life • 3.5 billion hours/year time delay • 5.7 billion gallons of wasted gas/year • Total cost of $75 billion for the 75 urban areas 2010 FHWA Presentation - Reggie Holt, Sr. Bridge Engineer
Work Zone Safety • Continued need for Accelerated Construction and methods to close fewer lanes TRB DCG Critical & Cross Cutting Issues, 01-14-11
Work Zone Safety • As many as 1000 fatalities occur each year in roadway construction work zones TRB DCG Critical & Cross Cutting Issues, 01-14-11
Financial Assessment of Drainage Structure • Cost of supply • Cost of proper installation & inspection
Financial Assessment of Drainage Structure • Cost of supply • Cost of proper installation & inspection • Maintenance
Financial Assessment of Drainage Structure • Cost of supply • Cost of proper installation & inspection • Maintenance • Service Life versus Project Life
U.S. Army Corps of EngineersNo. 1110-2-2902 Engineering and DesignConduits, Culverts, and Pipes (31 March 1998) • CONCRETE- Most studies estimated product service life for concrete pipe to be between 70 and 100 years.Of nine state highway departments, three listed the life as 100 years, five states stated between 70 and 100 years, and one state gave 50 years. • (2) STEEL - Corrugated steel pipe usually fails due to corrosion of the invert or the exterior of the pipe.Properly applied coatings can extend the product life to at least 50 years for most environments. • (3) ALUMINUM- Aluminum pipe is usually affected more by soil-side corrosion than by corrosion of the invert. Long-term performance is difficult to predict because of a relatively short history of use, but the designer should not expect a product service life of greater than 50 years. • (4) PLASTIC- Many different materials fall under the general category of plastic. Each of these materials may have some unique applications where it is suitable or unsuitable. Performance history of plastic pipe is limited. A designer should not expect a product service life of greater than 50 years. Excerpt from Para. 1-4 Life Cycle Design
Risk Assessment • Modes of Failure
Road Closed but they’re Open for Business
User Delay Costs (Indirect Costs) Joseph Perrin’s Research: D = AADT * t * d *(cv * vv * vof + cf * vf) Where: AADT = Annual Average Daily Traffic of the roadway which the culvert is being installedt = the average increase in delay or congestion the installation is causing to each vehicle per day, in hoursd = the number of days the project will takecv = the average rate of person-delay, in dollars per hour vv = the percentage of passenger vehicles traffic vof = the vehicle occupancy factor cf = the average rate of freight-delay, in dollars per hourvf = the percentage of truck traffic
User Delay Costs (Indirect Costs) Average Established Delay Costs as of 2005, in Dollars: cv = $18.62 per person / hour of delay cf = $52.86 per freight /hour of delay Typical Traffic Assumptions: vv = 97% vehicle passenger traffic vf = 3% truck traffic vof =1.2 persons per vehicle A one-hour delay on a roadway carrying an Annual Average Daily Traffic of 20,000 vehicles costs the public over $450,000 every day.
Risk Assessment • Modes of Failure
Financial Assessment of Drainage Structure • Cost of supply • Cost of proper installation & inspection • Maintenance • Service Life versus Project Life
It is unwise to pay too much, but it is worse to pay too little. When you pay too much, you lose a little money. When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do. JOHN RUSKIN 1819-1900, renowned English critic, social commentator, and economist of the Victorian Age
Advantages ofPrecast Concrete Structures Cast and Cured in a Quality Controlled Environment Shows up at the Jobsite as a Structure Strength is All Ready “Built In” Just Set, Connect… and Go! Save Time & Money! Precast Concrete = Long Service Life