Abstract：The deformation behaviors of oil tank foundation，which sits on deep-thick liquidated soft soil of the estuarial coastal area，are studied in this paper. The soft soil is treated with gravel piles, plastic drainage bands and water filling preload. Through the long-term monitoring of deformation of the deep soil and surface soil, a great number of primitive data were obtained. In this paper, the plane inclination and non-plane inclination of the surface and deep soil, and the sway settlement of the round wall are discussed. The settlement of the oil tank foundation is analyzed and evaluated. At last, the reasonable distance between tanks，the rational depth for the settlement calculation and empirical factors of the settlement are also presented.
