Case History: New South Runway Design and Construction at Fort Lauderdale International Airport: Geotechnical and Pavement Considerations

As part of the airport expansion program at Fort Lauderdale International Airport, Broward County selected a team to replace the old runway and design a new south runway and associated taxiways. The runway and the parallel Taxiway J extend over the existing Florida East Coast Railway and US Route 1 by using an earth embankment and an elevated bridge structure. During construction, Fort Lauderdale International Airport was the busiest airport in the country operating with a single runway. The earth embankment was a major challenge due to the expected vertical and horizontal displacements. An extensive geotechnical investigation was conducted to define the characteristics of the subsurface stratums. The P-152 earthwork and other associated specifications were modified to minimize the primary settlement in the embankment to allow for the construction of the new pavement within a reasonable timeframe. The secondary settlement was monitored to promptly address any issues that could affect the integrity of the new airfield pavement. The life-cycle cost and settlement analyses indicated that under a controlled embankment construction and surcharge process, a portland cement concrete pavement was advantageous over an asphalt pavement. The transition slabs to the approach slabs were reinforced and dowelled so that they could be slabjacked if significant differential settlement is obtained between the embankment and the bridge structure. Due to the extensive area of concrete pavement to be constructed, it was decided to modify the P-501 specification by requiring slip form paving with a dedicated on-site batch plant. The mixture required dense graded aggregate mixtures, and other material requirements to improve the quality of the end product. Construction of the concrete pavement was a learning curve since concrete pavement construction of this magnitude and process was a first to South Florida. This paper summarizes key design elements affecting the construction and long term performance of the airfield pavements.