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Design Deviation Examples November 2011. ODOT Bridge Design Exchange Nov. 10, 2011. Design Deviations – Nov. 2011. During Design (better) More time to consider & refine proposal During Construction (not so good) Usually something has gone wrong Time and $$ pressure for resolution.
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Design Deviation Examples November 2011 • ODOT Bridge Design Exchange • Nov. 10, 2011
Design Deviations – Nov. 2011 • During Design (better) • More time to consider & refine proposal • During Construction (not so good) • Usually something has gone wrong • Time and $$ pressure for resolution
Design Deviations – Nov. 2011 • R1 US30 at Eilertsen Creek Br 21455, kn 17037 • New bridge to replace culvert • Request for ACWS instead of Concrete • ADT favored concrete deck • Desire to finish in one in-water work period • District commitment to maintain ACWS
Design Deviations – Nov. 2011 • R1 Hwy. 160 over Washington St. Br 21417 • Requested wider steel girder spacing, and “W” cross frames • Saved a girder line and some $$
Design Deviations – Nov. 2011 • R2 Bundle 513 OR200 Bear Creek • Column Hoops: Construction request to use Caltrans “Ultimate Butt Splice” Weld instead of ODOT details • “Why?” Caltrans specs are rigorous for weld procedures and testing • Supplier (in CA) used automated welding equipment • Lab tests: bars broke first, welds held
Design Deviations – Nov. 2011 • R1 US26 Bundle 511 • E. Fork Dairy Creek Br 21323, • McKay Creek Br 21322 • Prestressed Slab bridges • Std. ODOT details use ½” Strands • Design calcs used 0.6” Strands • Fabricator used same number of ½” Strands • Replace McKay slabs, Keep Dairy Cr. Slabs & make continuous over bents
Design Deviations – Nov. 2011 • R3 I-5 Curtiss Creek Bundle 508 Br 21306 • Was designed & built • Load rating: Bent-2 Column inadequate for Live Loads • What to do?
Design Deviations – Nov. 2011 • I-5 Curtis Creek, cont. • Early proposed solution: • Jacket column w/ reinforced concrete • Mech. splice vert. bars to shaft rebar • Bar tops: Resin bonded into X-beam • Our concerns: overhead drilling approx. 3’ deep, overhead resin bonding
Design Deviations – Nov. 2011 • Questions? Discussion?
Thank You kevin.f.davidson@odot.state.or.us 503-986-3342