针对场地上部为吹填海砂、下部为粉砂的特殊地层条件，在储存罐的基础中采用了普通直孔灌注桩和三节DX旋挖挤扩灌注桩；通过现场自平衡载荷试验，判定桩的竖向抗压极限承载力和沉降量，分析桩的载荷传递机理，并对桩侧阻力、桩端阻力的分配和发展规律进行研究；同时通过对两种桩的试验结果进行对比，发现DX挤扩灌注桩的极限承载力、桩身沉降明显优于普通直孔灌注桩，而且DX桩的长度明显小于直孔桩。

In this paper, considering the special field with hydraulic fill sand in upper soil layer and fine sand in the lower soil, we adopt straight piles and DX piles in foundation of LNG storage tanks; a series of self-balanced load tests for piles are conducted. The purpose is to determine the ultimate bearing capacities and settlement of piles, analyze its load transfer mechanism, and study the distribution and development of the skin friction resistances and tip resistances. Comparing DX piles with straight piles, we find that DX piles are superior in ultimate bearing capacities and settlement; at the same time, the length of DX piles can be reduced apparently.