Using Strut-and-Tie Model for Concrete Hammerhead Design

Periodically, construction-based confinements or aesthic aspects gets desiners kindled to utilize single column piers (hammerhead) bridges. Some factors such as geometrical discontinuities and inserted loads would be conducive to generate disturbed stress distribuition; consequently, such cases deserve special consideration, instead of conventional-adopted methods. Strut-and-Tie Model (STM), as a simply- and newly- designed approach in concrete structure, seems to be a robust tool to deal with the problem. This is a lower bound solution of constraint analysis could be deployed to analyze concrete structures with disturbed stress distribution and a set of compressive and tensional components. By using 3 STMs, a sylindrical-shaped bridge pier was elastically drawn. To get deformation and bearing load evaluated, nonlinear analysis through ABAQUS software was performed. Derived outputs illustrated that not only do those samples designed by STM possess enough resistance, but also they present adequate behavior. It is true that this methdeology is known as a lower bound solution; however, not only is this cost effective more than 35% over against conventional STMs as long as rebar arrangement allows, but it also tends to utilize rebar far less (by 29%) than common designing method (LRFD) and final resistance. It is worth to bear in mind that this figure would be considerable in big projects of bridge construction. Addtionally, analysis of designed specimens demonstrates that this design would possess more ductible behavior and experience a smooth failure.