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CALTRANS COMPONENT REPAIR MODELS. by Stuart D. Werner for presentation at Third Tri-Center Workshop Las Vegas NV October 13-14, 2004. BASIS FOR MODELS: Judgment/Experience of Caltrans Staff. Bridges Tom Harrington and Steve Sahs Approach Fills Kirsten Stahl, Dan Adams, Minh Ha Tunnels
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CALTRANS COMPONENT REPAIR MODELS by Stuart D. Werner for presentation at Third Tri-Center Workshop Las Vegas NV October 13-14, 2004
BASIS FOR MODELS:Judgment/Experience of Caltrans Staff • Bridges • Tom Harrington and Steve Sahs • Approach Fills • Kirsten Stahl, Dan Adams, Minh Ha • Tunnels • Randy Anderson, Ray Mailhot, Umakant Dash, Bob Delbarrio • Roadway Pavements • Bill Farnbach, Tinu Mishra, Brian Weber, Leo Mahserelli
REPAIR MODELS: Purpose • For a Given Damage State, Repair Models will Estimate: • Repair Costs • Repair Durations • Functionality (Traffic State) during Repairs • These will Differ for Different Regions of U.S. due to Differences in: • Available Repair Resources • Component Construction, Maintenance, and Repair Practices
REPAIR MODELS:Component Functionality (i.e., Traffic State) • Percent of Pre-EQ Traffic-Carrying Capacity that can be Accommodated by Component while Repairs are Proceeding • Varies with Time after EQ • To Reflect Estimated Rate of Repair of Damaged Component • REDARS Currently Represents Reduced Functionality as: • Reduced Lanes • In Practice, Can Also Use Other Metrics, e.g., • Reduced Speeds • Load Restrictions
REPAIR MODELS:Role in REDARS Analysis (For One EQ/Simulation and Four Previously-Selected Post-EQ Times) • Repair Models Estimate Traffic States for All Components in Roadway Network • After Damage States have been Estimated • For Damaged Components • Their Roadway Link will Have Reduced Traffic-Capacity • System-State Model of Entire Roadway Network is Formed (shows all link traffic-carrying capacities throughout network) • Transportation Network Analysis Procedure is Applied to System-State Model (estimates post-EQ travel times)
REPAIR MODELS:Assumption 1 • Current REDARS Repair Models • Assume Required Repair Resources are Immediately Available • However, if There are Many Damaged Components: • Available Repair Resources will be Stretched • This will Increase Repair Times Given in Repair Model
REPAIR MODELS:Assumption 2 • Use California (Caltrans) Repair Models as Default: • Only Region in U.S. with Significant Recent Experience in Actual Post-EQ Highway-Roadway Repairs • For Other Regions of U.S. • Caltrans Repair Models can be Frame of Reference (Starting Point) • Should be Modified to Account for Differences in Repair Resources/Practices, Construction Practices, etc.
BRIDGE REPAIR MODEL: DEFAULT REPAIR COSTS • Repair Cost = Repair Cost Ratio (RCR) x Replacement Cost (REP) • Default Replacement Cost = $150/ft2 x Bridge Deck Area • $150/ft2 is Caltrans unit cost for typical cast-in-place prestressed concrete box-girder bridge in Northern California • Default Replacement Cost and RCR can differ for other materials of construction and regions of U.S.
DEFAULT REPAIR COST MODELS: OTHER COMPONENTS • Approach Fills • Due to EQ-Induced Settlement • Based on California Construction/Repair/Maintenance Practices, and Typical RCRs and REPs • Assumed Settlement Ranges for Damage States 1, 2, and 3 • Roadway Pavements • Due to EQ-Induced Permanent Ground Displacement (PGD) • Based on California Construction/Repair/Maintenance Practices, and Typical RCRs and REPs • Assumed PGD Ranges for Damage States 1 through 5 • Tunnels • Due to Ground Shaking and PGD • Based on Construction and Maintenance Practices for Caldecott Tunnel through Oakland-Berkeley Hills