Finite-Element Simulation and Cost-Benefit Analysis of Full-Scale Skewed Inverted-T Bridge Caps with Traditional and Skew Reinforcements

Abstract

In highway design, inverted-T bridge caps (ITBCs) have been extensively used in the United States. Depending on the project requirements, some ITBCs need to be skewed. In Texas, the traditional method of flaring the transverse reinforcement out is used to design the skewed ITBCs, as stated in the Texas Department of Transportation (TxDOT) Bridge Design Manual. However, this method has significant drawbacks in terms of design and construction. To solve the complexities of the traditional method, the skewed reinforcing method is proposed to TxDOT. In this paper, to enlarge the knowledge of the structural behavior and the economic impact of skew reinforcing in ITBCs, the nonlinear finite-element (FE) simulation and cost-benefit analysis of 96 full-scale skewed ITBC models are performed. The structural and economic performance of the specimens are investigated and compared according to the following design variables: (1) skew angle; (2) transverse reinforcement detailing; (3) amount of the transverse reinforcement; (4) presence of the end reinforcement; (5) size of the diagonal end reinforcement; and (6) the concrete strength. The finite-element analysis shows that skew reinforcing can achieve better structural performance than the traditional method in terms of stiffness, crack width, and the ultimate capacity. Moreover, the skew transverse reinforcement method considerably reduces the design and construction costs.