The evaluation of the differential settlements due to the variability of the subsoil properties, is important problem to construct the airport facilities on the soft ground. In the present sutdy, a numerical method to evaluate the differential settlements is newly developed. The results of the study is summarized as follows:
1) FUTO88, the new computer program to evaluate the differential settlements in the reclaimed land, is developed. In FUTO88, the probabilistic models of the soil; properties, including the horizontal correlation of soil properties, is used. The effect of the three dimensional distribution of the settlements of the deep layer is also taken into consideration.
2) The extensive settlements observations were carried out in Offshore Development Project of Tokyo International Airport. The results of the numerical simulation with FUTO88, agreed favorably with the statistic properties of the observed settlements.
3) Based on the calculation with FUTO88, the practical chart to evaluate the differential settlements in the typical reclaimed land is proposed.
4) The damages of airport pavements due to the future differential settlements can be predicted with FUTO88.