勘察技术在特殊构造性承压水场地桩基施工中的应用  

Application of Survey Technology in Pile Foundation Construction of Special Structural Confined Water Field

作　　者：党智荣 王志中 党静茂 杨少飞 Dang Zhirong;Wang Zhizhong;Dang Jingmao;Yang Shaofei(China Jikan Research of Engineering Investigations&Design Co.,Ltd.,Xi’an 710043,Shaanxi,China;Northwest Branch of China Construction Eighth Engineering Bureau Co.,Ltd.,Xi’an 710075,Shaanxi,China)

机构地区：[1]机械工业勘察设计研究院有限公司,陕西西安710043 [2]中国建筑第八工程局有限公司西北分公司,陕西西安710075

出　　处：《岩土工程技术》2022年第2期129-134,共6页Geotechnical Engineering Technique

摘　　要：针对某工程旋挖钻孔灌注桩实施过程中出现的严重冒水涌砂现象,利用勘察技术对该问题进行分析研究,认为冒水涌砂问题来自于特殊构造性承压水的作用。对此,提出了改用正循环成孔工艺,通过增加泥浆比重及黏度来减小地下承压水水头压力,减轻或消除孔底涌砂现象。再采用加大桩径、增加桩长、对桩侧泥皮及桩端沉渣用后压浆进行处理,有效解决了该工程桩基施工中不同工艺可能造成的承载力及变形有较大差异的技术难题,保证了桩基承载力及变形均满足设计及规范要求。In view of the serious phenomenon of water and sand gushing during the implementation of the rotary drilling cast-inplace pile, the problem was discussed according to survey technology. The problem of water and sand gushing comes from the effect of the special structural confined water. In order to solve this problem, reverse circulation drilling technology was proposed to reduce the head pressure of underground confined water and reduce or eliminate the sand gushing at the bottom of the hole by increasing the mud specific gravity and viscosity. Then, the post-grouting process was used to deal with the mud skin effect on the side of the pile and the sediment at the end of the pile, and the measures such as increasing the diameter and length of the pile were adopted to effectively solve the technical problems. It effectively solves the technical problem that the bearing capacity and deformation may be greatly different caused by different processes in the pile foundation construction of the project, and ensures that the bearing capacity and deformation of the pile foundation meet the requirements of the design and specifications.

关 键 词：勘察技术 构造性承压水 锅锥旋挖成孔 正循环钻机成孔 

分 类 号：TU195.1[建筑科学—建筑理论]