Abstract: A soil improvement work was performed at end of runway under operation for the runway extension project. The constraints for the construction activities were, short effective working time windows, restrictive requirements for the equipment and operation headroom, adverse night working environment, high quality requirement on the post construction performance for the extended runway after the soil improvement. This paper presents a case history of a soil improvement work performed at the end of an active runway. The vacuum preloading method was able to be applied at the ends of the operational runway with active air traffic. The bearing capacity of the improved soft soils is evaluated. Construction measures and procedures applied in the soil improvement work are also reviewed in the paper.

Key words: Construction under Operation Conditions, Runway Lengthening, Soil Improvement, Vacuum Preloading