The objectives of this paper are to （I） quantify the effects of age and other key factors on bridge deterioration rates, and （2） provide bridge managers with strategic forecasting tools. A model for forecasting su...The objectives of this paper are to （I） quantify the effects of age and other key factors on bridge deterioration rates, and （2） provide bridge managers with strategic forecasting tools. A model for forecasting substructure conditionisestimated from the National Bridge Inventory that includes the effects of bridge material, design load, structural type, operating rating, average daily traffic, water, and the state where the bridge is located. Bridge age is the quantitative independent variable. The relationship between age and substructure condition is a fourth-order polynomial. Some of the key findings are： （I） a bridge substructure is expected to lose from 0.52 to 0.11 rating points per decade as it ages from 10 to 70 years; （2） levels of deterioration increase significantly as the material changes from concrete, to steel, to timber; （3） slab bridges have lower levels of deterioration than other structures; （4） bridges that span water have lower condition ratings; （5） bridges with higher operating ratingshave higher condition ratings; and （6） substructure condition ratings vary significantly among states.展开更多
文摘The objectives of this paper are to （I） quantify the effects of age and other key factors on bridge deterioration rates, and （2） provide bridge managers with strategic forecasting tools. A model for forecasting substructure conditionisestimated from the National Bridge Inventory that includes the effects of bridge material, design load, structural type, operating rating, average daily traffic, water, and the state where the bridge is located. Bridge age is the quantitative independent variable. The relationship between age and substructure condition is a fourth-order polynomial. Some of the key findings are： （I） a bridge substructure is expected to lose from 0.52 to 0.11 rating points per decade as it ages from 10 to 70 years; （2） levels of deterioration increase significantly as the material changes from concrete, to steel, to timber; （3） slab bridges have lower levels of deterioration than other structures; （4） bridges that span water have lower condition ratings; （5） bridges with higher operating ratingshave higher condition ratings; and （6） substructure condition ratings vary significantly among states.
