05/29/2026
As part of Phase One on the Woodlawn Reconstruction, construction crews excavated the existing roadway to the bottom of the 2-foot rock layer. After some initial testing, Professional Engineering Consultants (PEC) requested a proof-roll, which revealed several areas of soft subgrade. Because of the extensive geotechnical investigations and testing that occurred prior to reconstruction, it was anticipated that soft subgrade would be encountered on this project. However, the extent of the soft subgrade was surprising.
Thankfully, this was discovered before the construction crews began laying the aggregate base. All parties agreed that a pause in the reconstruction efforts was needed to determine the best path forward.
Initially, the on-site recommendation was to chemically stabilize the soil with calcium oxide (lime) in order to provide a solid base from which to build on. To determine what percentage of lime needed to be added to the subgrade, KDOT began running soil samples through the KDOT lab. KDOT had to run at least three tests at different lime percentages to get the desired Plasticity Index (a measure of how much a soil can be deformed before it breaks) in the subgrade, which ultimately was an 8% lime mixture.
Removal and replacement of unstable subgrade with suitable engineered fill is also being calculated and considered at this time.
Final selection of the preferred approach remains subject to KDOT and City review and approval. A formal change order for the proposed soil stabilization work must be prepared, presented, and approved by the City Council.
The Council is currently awaiting receipt of the change order and is prepared to hold a special meeting as soon as it becomes available. Following Council approval, the change order will receive final authorization from KDOT, allowing for materials to be ordered and work to resume thereafter.
While reconstruction delays are frustrating, it is important that this reconstruction effort is successful. The City will continue to provide updates as the change order moves through the approval process and will announce a revised construction schedule as soon as one is available. We appreciate the community's patience as we work through these challenges and move the project forward.
