上海深厚砂层旋挖桩施工关键技术研究  

Research on Key Construction Technology of Rotary Excavation Pile in Deep Sand Layer in Shanghai

作　　者：贾宝荣 邵治理 朱其凯 方华 JIA Baorong;SHAO Zhili;ZHU Qikai;FANG Hua(Shanghai Mechanized Construction Group Co.,Ltd.,Shanghai200072,China)

机构地区：[1]上海市机械施工集团有限公司,上海200072

出　　处：《施工技术（中英文）》2024年第19期25-29,共5页Construction Technology

基　　金：上海市“科技创新行动计划”启明星项目(扬帆专项)(23YF1436800)。

摘　　要：东方枢纽上海东站项目所处区域地质条件特殊,地表30m以下为深厚砂层,第(7)层、(9)层呈连通状态,采取常规旋挖施工工艺易缩径塌孔、孔底沉渣厚度达数米,施工质量难以保证。通过现场试验确定施工参数,从护壁泥浆配合比、深厚砂层成孔稳定性、施工工艺及设备改造等多方面开展研究,分析了深厚砂性土层中旋挖桩存在的主要问题,分别为地表孔口塌陷、抽吸负压效应和深层砂性土体缩径,采用护筒长度优化、钻头形式改造和泥浆参数控制等针对性优化措施,可确保深厚砂层中旋挖桩成孔质量,进一步总结形成了软土深厚砂层特殊地质条件下旋挖桩施工关键技术。The geological conditions of Shanghai East Railway Station of Eastern Hub located are special.The deep sand layer is below 30m on the surface.The 7th and 9th layers are connected.When the conventional rotary excavation construction technology is adopted,the rotary excavation pile construction is prone to shrink and collapse,and the thickness of the sediment at the bottom of the hole is as deep as several meters,hence,the construction quality is difficult to guarantee.The construction parameters are determined by a field test.The research was carried out on the aspects of wall mud mix ratio,hole-forming stability of deep sand layers,construction technology and equipment transformation.The main problems of rotary drilling piles in deep sand layers,which are surface orifice collapse,suction negative pressure effect,and deep sand soil shrinkage,were analyzed.The targeted optimization measures of casing length optimization,drilling bit form transformation and mud parameter control can ensure the hole-forming quality of rotary drilling piles in deep sand layers.The key technology of rotary drilling pile construction under special geological conditions of deep sand layers in soft soil is further summarized and formed.

关 键 词：车站 桩基础 旋挖桩 泥浆护壁 稳定性 施工技术 

分 类 号：TU753.3[建筑科学—建筑技术科学]