云南某特厚粉细砂覆盖型喀斯特地区的桩基础施工技术

Pile Foundation Construction Technology in a Karst Area Covered by Extra Thick Silt and Fine Sand in Yunnan Province

为解决特厚粉细砂覆盖型喀斯特地区桩基础施工存在的坍孔、漏浆、钻孔偏斜等问题,进行了施工方案比选,最终采用冲击成孔+抛填弃土(拌和了羧甲基纤维素钠)、块(片)石加固、护壁等施工方案。实践证明,上述施工方案能有效解决喀斯特地区桩基础施工难题,保证成桩质量,同时还能有效利用弃土,降低了施工成本,对类似地质条件的桩基础施工具有一定的指导价值。

In order to solve the problems of slump,slurry leakage and drilling deviation in the pile foundation construction in karst area covered by extra thick silt and fine sand,the construction plans were compared,and finally the construction plans of impact holing+dumping of discarded soil(mixed with sodium carboxymethyl cellulose),block(slice)stone reinforcement and retaining wall were adopted.Practice has proved that the above construction solutions can effectively solve the pile foundation construction problems in karst area,ensure the quality of piles,and at the same time,effectively utilize the discarded soil to reduce the construction cost,which has certain guiding value for the pile foundation construction under similar geological conditions.