Abstract:
The existing sub-grade of the Tampuling Airport runway in Tembilahan City, Riau Province is in the group of peat soil with the depth of more than 30 m. The compressibility rate type of this soft soil is very high. Based on “the worst case scenario” without any soil stabilization treatment, it was estimated that the soil consolidation rate would reach 1.7 metres, within 20 years of period of settlement time. In order to speed up its consolidation process to stabilizing the soil (for becoming a sub-grade the run way), the vertical drain method was applied. The procedures for designing of pre loading for the soil, as well as the calculation of the distance between vertical drains are then demonstrated in this paper. It was recommended that the depth of the designed vertical drain would be 18 metres, with the distance between the vertical drains is 1.2 metres each; height of the soil pre loading is 4.5 metres. With these design parameters, it was expected that the settlement process would be accelerated by 40 folds (235 months to become 6 months period).
