二灰砂桩是作者近几年研制成功的一种地基处理新方法，１９９２年被中国专利局受理为发明专利。该项专利在石灰、粉煤灰和砂三种材料配合比及加水、加压技术等方面有重大突破。本文仅就４个工程实例阐述二灰砂桩对填土地基的加固机理与加固效果。 The lime sand pile is a new method of foundation treatment developed by the author in recent years. It was accepted as a patent for invention by the Chinese Patent Office in 1992. The patent has made major breakthroughs in the mixing ratio of lime, fly ash and sand, and the addition of water and pressure technology. In this paper, the reinforcement mechanism and reinforcement effect of the lime sand piles on the filling foundation are described in four engineering examples.