提升软土条件下桥梁旋挖扩底桩成桩质量的施工工艺研究

Research on the Construction Technology of Improving the Quality of Bridge Rotary Excavation Belled Pile under the Soft Soil Condition

针对软土地区桥梁基础施工中旋挖扩底桩技术的应用,基于普通地质条件的施工先例及规范难以直接提供有效的技术指导,文章以吴淞江工程(上海段)新川沙河段桥梁2标沪太路飞云桥为例,对软土地区进行的旋挖扩底桩施工的施工工艺,从泥浆配比、泥浆循环系统、钻孔技术、扩底技术4个方面进行了优化。结果表明,优化后的施工工艺能够保证较高的成桩质量,同时节省了成本,取得了较好的经济效益,对于后续类似工程在软土条件下进行桥梁旋挖扩底桩施工具有一定的借鉴意义。

In response to the application of rotary excavation and expansion pile technology in bridge foundation construction in soft soil areas,it is difficult to provide effective technical guidance directly based on construction precedents and specifications under ordinary geological conditions.Taking the Feiyun Bridge on Hutai Road in Section 2 of the Xinchuansha River section of the Wusong River Project(Shanghai section)as an example,it optimizes the construction process of rotary excavation and expansion pile construction in soft soil areas from four aspects:mud ratio,mud circulation system,drilling technology and bottom expansion technology.The results show that the optimized construction process can ensure high pile quality,save costs,and achieve good economic benefits.It has certain reference significance for similar projects to carry out bridge rotary excavation and expansion pile construction under soft soil conditions in the future.