某住宅楼采用端扩灌注桩基础，桩身直径0．4m，桩长9．0m，桩端扩底直径10m，总计298根螺旋钻孔扩底灌注桩。根据地质条件和设计要求，选用双城钻机厂生产的GZL400型螺旋工程钻机，端扩机械采用旋转式扩孔机，工期提前15d，桩身质量及单桩承载力大大超过设计要求，桩基质量良好 A residential building adopts end-expanded cast-in-place pile foundation. The diameter of the pile is 0.4m, the length of the pile is 9.0m, and the diameter of the end of the pile is 10m. A total of 298 auger boreholes are used to extend the bottom of the pile. According to the geological conditions and design requirements, the GZL400 spiral construction drilling rig produced by the Shuangcheng Drilling Plant was selected. The rotary drilling machine was used for the end expansion machine. The construction period was advanced by 15 days. The pile quality and the bearing capacity of the single pile greatly exceeded the design requirements. good