本文介绍了大直径扩底桩的地基变形特点，讨论了桩端面积效应问题，阐述了按变形确定竖向承载力的原理和方法。文中提出的承载力取值和沉降计算是一套适合于我国大直径扩底桩的设计方法。 This paper introduces the characteristics of the foundation deformation of the large diameter enlarged bottom pile, discusses the area effect of the pile tip, and expounds the principle and method of determining the vertical bearing capacity according to the deformation. The calculation of bearing capacity and settlement proposed in the paper is a set of design methods suitable for large diameter enlarged bottom piles in China.