摘要
大直径超长灌注桩作为超高层建筑普遍使用的一种桩型,具有承载力高、有效减小建筑物沉降的特点。桩基所处地质环境复杂,桩周土性质、土层分布情况等均会对桩侧摩阻力产生很大影响,地勘结果在桩侧阻力的取值上比较保守。桩端桩侧联合注浆可有效提高单桩承载力,目前在黄土地区注浆工艺对桩侧阻力的提高效应方面缺乏设计经验。通过对黄土地区桩基注浆前后试桩测试结果的研究,分析了注浆前后桩身轴力、桩顶沉降及侧摩阻力的变化规律,提出桩侧极限阻力具有深度效应,并根据试桩结果给出了注浆条件下桩侧阻力的增强系数,提出了实用的设计方法;同时根据试桩结果对工程桩进行了优化设计,优化后的桩基承载力经检测满足设计要求,取得了良好的经济效益。
Large diameter super long cast-in-place pile is a kind of pile type widely used in super high-rise buildings, has the characteristics of high bearing capacity and effetive buildings settlement decrease. The site condition of pile foudation is complex. It means properties of the soil surrounded and the distribution of soil layers will have a great impact on side friction resistance, so that the result shown in geological prospecting report shall be hedging. Pile end and pile side joint grouting effectively improves the bearing capacity of single pile. However, the improvement effect of lateral friction is lack of design experience in loess area. Based on the test results of axial pile force, pile top settlement and lateral resistance before and after grouting of pile foundation in loess area, proposing the lateral friction shows the phenomenon of “deep effect”, and giving the adviced enhancement coefficient of lateral friction under grouting condition. Finally, the bearing capacity of the pile foundation after the optimized design meets the design requirements, a better economical benefit is obtained.
作者
丁凯
寇利军
宋臣
王明明
车佳奇
DING Kai;KOU Lijun;SONG Chen;WANG Mingming;CHE Jiaqi(East China Architectural Design and Research Institute Co.,Ltd.,Xi’an 710054,China)
出处
《建筑结构》
CSCD
北大核心
2022年第S02期2075-2079,共5页
Building Structure
关键词
黄土地区
注浆
侧阻分布
深度效应
桩基优化
loess area
grouting
lateral resistance distribution
deep effect
pile foundation optimization
