为了发挥直孔灌注桩的优势,结合北京地区工程地质特点,改进直孔灌注桩的缺点,提出了钻孔扩底灌注桩的设想。我公司1979年研制了 KZ-120型及 KZY-100型两种扩孔器,于1980年在北京劲松小区做了42根钻孔扩底灌注桩工艺试验及15根荷载试验桩,并完成了一幢6层框架轻板结构住宅基础施工,作为工艺考核,取得了初步成果,为钻扩桩的推广使用准备了施工技术条件。 In order to take advantage of the advantages of straight bored cast-in-place piles, combined with the characteristics of engineering geology in Beijing, to improve the shortcomings of bored bored cast-in-place piles, the concept of bored borehole cast-in-place piles was proposed. In 1979, our company developed two types of KZ-120 and KZY-100 reamers. In 1980, 42 drilling boring piles and 15 load test piles were completed in Jinsong Community in Beijing and completed. The construction of a 6-story frame light-slab structure residential foundation, as a process assessment, achieved preliminary results, and prepared technical conditions for the promotion and use of drilling and expanding piles.