孔桩开挖施工标准化手册

厦门至成都公路贵州境

毕节至生机（黔川界）段

孔桩开挖施工作业标准化操作手册二〇一二年十一月目录

1施工准备·····························································11.1技术准备·······················································11.2施工现场准备·················································21.3施工机具························································52挖掘工艺·····························································82.1挖掘程序·······················································82.2挖孔质量要求················································92.3挖孔排水······················································102.4孔桩护壁······················································112.5终孔检查······················································153文明施工及安全、环保要求····································143.1标志、标牌····················································143.2孔口围护·······················································153.3安全用品·······················································163.4通风·····························································173.5爆破·····························································183.6环保措施·······················································1911施工准备1.1技术准备1)在开工报告批复后，编制单项施工组织设计和专项安全方案，向作业班组进行书面的三级技术交底和安全交底。2)施测墩台十字线,定出桩孔准确位置,设置护桩并记录,经常检查校核。21.2施工现场准备1.2.1场地准备平整场地,清除坡面危石浮土;坡面有裂缝或坍塌迹象者应加设必要的保护措施,铲除松软的土层并夯实。31.2.2锁口施工每个孔桩开挖前,将孔位四周的场地整平,进行夯实并硬化。锁口可采用C25混凝土施工成矩形,且高出地面30cm,锁口参照长宽尺寸:φ1.8m桩孔为2.4×2.4m、φ2.0m桩孔为2.6×2.6m、φ2.2m桩孔为2.8×2.8m。锁口四周场地平整后,采用M7.5水泥砂浆抹面,厚度1cm。平整面积根据现场实际情况确定。4锁口采用C25混凝土施工成矩形锁口高出地面30cm51.3施工机具1.3.1电动吊机挖掘采用电动吊机,用10KN-20KN慢速卷扬机提升,卷扬机要设限位器。6出料吊机须安装稳定，特别是配重须稳固。71.3.2提碴吊桶

吊桶要坚固结实，吊环应采用Ⅰ级钢筋加工，吊钩应安装保险卡扣。82挖掘工艺2.1挖掘程序

挖掘程序视土层性质及桩孔布置而定。挖孔由人工自上而下逐层用镐、锹进行,遇坚硬土层用锤、钎破碎,遇孔内岩石则采用浅眼爆破,开挖由中部向周边进行。92.2挖孔质量要求在挖孔过程中,应经常按每节护壁检查桩孔尺寸和平面位置。1)群桩桩位误差≯10Omm;排架桩桩位误差≯50mm,极值≯100mm。2)直桩倾斜度不超过0.5%桩长,且不