With a full year to prepare for Derby City’s Labor Day event, the Louisville Sports Authority set plans in motion to build a renovated BMX ramp. BMX tracks stand apart from traditional sports venues as each course varies in length, design, and complexity, offering riders a unique challenge every time. The BMX track would also offer our wall designers a unique challenge…

This project presented several engineering challenges that complicated design and construction. Large precast Redi-Rock blocks were chosen as the best option for the five proposed retaining wall structures. Other retaining wall technologies had been considered, but each system was rejected based upon concerns about cost, constructability, and long-term performance. The maximum wall height for this project was 30-feet and required 90-degree corners with no horizontal set-back.

“From a Redi-Rock standpoint, this project had it all. We had to use 60 inch and 48 inch blocks, large batter walls, gravity walls, and positive connection walls. Construction was a challenge because we had to maneuver and build in such a small space. We had to be careful not to disrupt any of the electrical systems for the tracks,” said Irvin Vittitow of Redi-Rock K.I.T.

Three retaining walls were designed to wrap around and support the BMX ramp, with the largest wall stabilizing the stairway to the top. Due to the ramp’s tight proximity to the walls, the engineering team used a hybrid (geogrid / gravity) system. Integration with the ramp was further complicated by clay soils of marginal shear strength. The tiered wall supporting the stairway required special design to withstand the high plasticity clay conditions.

Learn more about Derby City and their BMX track here.