振动沉管灌注桩缩径原因的分析及预防

通过对镇江开发区某工程振动沉管桩基础施工方法的总结，系统地论述了沉管灌注桩施工中发生缩径的原因，提出了预防措施。

Analysis of Cause of Shrink Diameter and Prevention for Vibro Pile

The vibro pile is characteristic of good compacting and improving of the physical and chemical properties for surrounding pile soil, high mechanical level, non pollution for the operation site, quick speed drilling and low cost without displacing nd hole making. The method is suitable for the variation of geological conditions. However,the accident of shrink diameter may occur due to underground drilling. The causes of shrink diameter are excess pore water pressure and expansion of soil, overspeed removal of pipe and poor quality concrete, small pile distance, different solum condition and solidification speed and uncompacted filled concrete. So, some prevention measures are carried out including control of removal speed of pipe, reasonable maintenance of concrete height in pile and control of strirring time of concrete, etc.