浅覆盖层陡岩面水中桩基础施工技术研究

Research on Construction Technology of Pile Foundation in Steep Rock Surface of Shallow Overburden Layer

针对浅覆盖层陡岩面上修筑桥梁桩基础的技术难题,结合毛家园大桥地质条件及工程特点对浅覆盖层地质条件下水中桩基础施工技术进行研究。主要从冲孔钢平台搭设方法、钢护筒引孔埋设施工方法及桩锤改造施工工艺,有针对性地研究浅覆盖层地质条件下水中桩基础施工技术。研究结果表明,采用"板凳墩"形式搭设水上钢平台可满足施工平台需要,运用钢护筒引孔埋设技术有效保证水中桩基础施工质量及安全,改造桩锤加大桩锤冲击力可缩短成孔时间,提高施工效率。

Regarding the technical difficulties in constructing bridge pile foundation on steep rock surface of shallow overburden layer,in the paper,the geological conditions and engineering characteristics of Maojiayuan Bridge are taken as background to study the construction technology of pile foundation under shallow overburden geological conditions.The construction technologies of pile foundation in shallow overburden under geological conditions are being targeted to study from the method of setting up steel platform,perforation construction in steel guard barrel and reconstruction of pile hammer.The results show that the construction platform needs can be met by setting up steel platform on water in the form of"bench pier".The quality and safety of pile foundation construction in water are effectively guaranteed by the technique of pilot hole of steel casing.The reconstruction of pile hammer to increase the impact can shorten the time of hole forming and improve the construction efficiency.