Fast-Track Installation of Micropiles to Resupport Settled Florida SR-60 Bridge End Bents

The end bents of an existing bridge located west of Lake Wales, Florida, experienced significant settlement, leading to concern about its stability. A detailed foundation inspection attributed the settlement to deterioration of the existing timber piles. The bridge was closed to traffic until both end bents could be remediated. An adjacent bridge handled both directions of traffic during the closure. The geotechnical contractor proposed a solution of micropiles installed through both end bents to restore the bridge's capacity. Timing was a critical component of the remediation work. The micropile program consisted of the use of rotary drilling techniques to install 20 micropiles through the end bents to a depth of 30 ft. The tops of the micropiles were bonded to the end bent pile caps. A load test was performed on a test pile installed adjacent to the existing bridge.