桩端后注浆灌注桩承载力异常原因探讨  

Discussion on Causes of Abnormal Bearing Capacity of Post Grouting at Pile End

作　　者：李玉灿 Li Yucan(China Shipbuilding Industry Institute of the Engineering Investigation&Design,Co.,Ltd.,Shanghai 200063,China)

机构地区：[1]中船勘察设计研究院有限公司,上海200063

出　　处：《岩土工程技术》2024年第4期436-439,共4页Geotechnical Engineering Technique

摘　　要：深厚软土层中的桩端后注浆灌注桩承载力受多重因素影响。以上海某项目的3组桩端后注浆灌注桩为研究对象,研究了在上海地区以粉细砂⑨层作为桩基持力层的桩端后注浆灌注桩的承载力影响因素,结果表明后注浆灌注桩承载力受成孔工艺、注浆工艺、沉渣厚度的影响较大。为规避上述因素影响,采用反循环成孔、循环泥浆除砂施工工艺,并对注浆孔结构进行改进,采用高低压力交替注浆使得注浆量大幅提高,孔底沉渣得到有效胶结,解决了该区后注浆灌注桩承载力不足问题。The bearing capacity of post grouting piles in deep soft soil layers is influenced by multiple factors.Taking three sets of post grouting piles at the pile end of a certain project in Shanghai as the research object,the influencing factors on the bearing capacity of post grouting piles were investigated,with the ninth layer of silt layer as the bearing layer of the pile foundation.The results indicated that the bearing capacity of post grouting piles was greatly influenced by the drilling process,grouting process,and sediment thickness.To avoid the influence of the above factors,the reverse circulation drilling and circulation mud sand removal construction technology were adopted,and the structure of the grouting hole was improved.The use of alternating high and low pressure grouting significantly increased the grouting amount,effectively cemented the sediment at the bottom of the hole,and solved the problem of insufficient bearing capacity of grouting pile in the area.

关 键 词：后注浆 沉渣 交替注浆 反循环 

分 类 号：TU473[建筑科学—结构工程]