预制桩基质量问题分析与处理  

Analysis and Treatment of Quality Problems of Prefabricated Pile Foundation

作　　者：周剑 刘洋 张建强 Zhou Jian;Liu Yang;Zhang Jianqiang(Northwest Engineering Corporation Limited of Power China,Xi'an 710065,China)

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,西安710065

出　　处：《特种结构》2018年第6期112-118,共7页Special Structures

摘　　要：表层覆有深厚软土、持力层起伏较大的场地,采用静压管桩施工,出现了低应变检测不合格、单桩静载荷试验检测不合格及斜桩等问题。本文结合施工及地层因素,指出低应变检测不合格的原因是断桩,断桩发生在焊接接缝处;单桩静载荷试验检测不合格的原因也是断桩,且断桩位置未入岩或入岩深度不足。随后,对所有桩基均进行低应变检测,根据检测结果,对缺陷深度小于9m的桩按废桩处理,缺陷深度大于9m的桩采用混凝土灌芯处理。最后,文章提出采用注浆微型钢管桩进行补桩,处理后桩基各项指标满足设计要求。Problems such as unqualified low strain detection, unqualified static load test of single pile and inclined pile may occur at sites subjected to the construction of static pressure pipe where the surface is covered with a deep soft soil and has a large fluctuation of the bearing stratum. Combined with construction and formation factors, this paper points out that the failure of low strain detection is caused by broken piles, which occur at welding joints. The failure of single pile static load test is also the cause of breaking pile, and the position of breaking pile is not in rock or the embedded depth of pile is insufficient. Subsequently, all pile foundations were tested for low strain. According to the test results, piles with defect depth less than 9 m were treated as waste piles, and those with defect depth greater than 9 m were treated with concrete core. Finally, the paper proposes that the grouting micro-steel pipe pile is used to reinforce the pile, and all indexes of the pile foundation after treatment meet the design requirements.

关 键 词：低应变检测 单桩静载荷试验 斜桩 注浆微型钢管桩 

分 类 号：TU476[建筑科学—结构工程]