Evaluation of Hammer Head Pier Cap Bridge Design

The design of D-regions of reinforced concrete beams is the past was based on rules of thumb and past experience. Strut-and-Tie Modeling (STM) is an accepted design method to deal with these D-regions and also for B-regions. It simply idealizes the entire structures, or portions of the structure as a truss where steel bar is placed according to the locations of the tension members. This report is written to investigate the use of strut-and-tie modeling with AASHTO LRFD provisions to design bridge structure which includes the girder, hammerhead pier caps & pier. A brief background on STM, STM as Standard Design Provision, Euro Code 2 Provisions for STM & a guide to design with STM using AASHTO LRFD is discussed. Design examples of a bridge structure of step-by-step are performed using STM with AASHTO LRFD section 5.6.3 provisions and compared with conventional method. Design example of hammerhead pier cap is also performed according to EURO Code provision to show the difference with ASSHTO LRFD provision for STM. The strength of struts and nodes according to AASHTO was checked in this report. Conclusions and Recommendations based on the findings of this report are listed. The important findings provided with this work are a refined procedure to guide designers using STM. The findings of this work show that STM with AASHTO LRFD & EURO Code 2 provisions can be an applicable design method for both the D-region & B-region of structures. However certain criteria need to be met and the engineer needs to give special consideration to the geometry of their models, crack control and concrete strength.