ISTHA 4168 Meacham Road Bridge
- 74 Drilled Shafts
- 22 Drilled Soldier Piles
- 150 WF of Sheeting
Meacham Road was widened to accommodate the interchange leading to the westbound and eastbound mainline of Interstate 90 in Cook County. The previous configuration of Meacham Road was three lanes in both the northbound and southbound direction, and proposed number of mainline lanes will remain the same. However, the widening portion of Meacham included adding additional turn lanes to accommodate the interchange leading to the I-90 mainline.
The four abutments in this project were originally designed to be supported on shell pile foundations. Therefore, an earth retention system was necessary to support approximately 25ft below Meacham Road in order to reach bottom of abutment elevation. In addition, a few constructability issues made this bridge a challenging project. The south abutment was directly under power lines which created an overhead limitation to the pile driving equipment, and utility lines sensitive to vibration were located within 20 feet of the proposed shell piles.
Value Engineering Design: In order to address the constructability issues that were encountered in this project, our alternative solution was to redesign the bridge to substitute shell piles for drilled shafts. The size of the drill and telescoping Kelly Bar eliminated the overhead limit issue which allowed for faster production. Furthermore, drilling the shafts minimized vibration which was critical for the nearby utilities. The alternative also resulted in a significant reduction in excavation and backfill quantities for the general contractor.