大直径嵌岩灌注桩竖向承载特性试验研究
Experimental study on vertical bearing characteristics of large diameter cast-in-place pile in mudstone foundation
赵香梅 1闫楠 1白晓宇 1韩磊 2蒋冲 3包希吉 2程海涛 4米春荣 4张明义1
作者信息
- 1. 青岛理工大学土木工程学院,山东青岛 266520
- 2. 中建八局第二建设有限公司,山东济南 250022
- 3. 中南大学资源与安全工程学院,湖南长沙 410083
- 4. 山东省建筑科学研究院有限公司,山东济南 250031
- 折叠
摘要
为了探讨泥岩地基大直径灌注桩竖向承载性能,依托青岛某机场桩基工程,对嵌入泥岩的9根大直径灌注桩进行了竖向抗压静载试验和桩身应力监测,分析大直径嵌岩灌注桩的竖向抗压性能,明确大直径灌注桩的荷载传递规律.结果表明,试桩桩身完整性较好,桩身质量可靠;试桩荷载-沉降(Q-s)曲线均为缓变型,加载初期存在明显的压密段,桩顶沉降量为10.31 mm,最低回弹率大于50％;最大荷载作用下,各试桩的竖向抗压极限承载力特征值均不小于6 480 kN,试桩竖向抗压承载能力仍有较大潜力;试桩均表现出端承摩擦桩的特性,轴力自桩顶到桩端逐渐衰减,桩侧摩阻力峰值发生在中风化泥岩段,桩端阻力占桩顶荷载的10.55％～34.48％.
Abstract
To explore the vertical bearing performance of large-diameter grouted piles on mudstone foundations,nine large-diameter grouted piles embedded in mudstone were subjected to vertical compressive static load tests and pile stress monitoring based on the pile foundation project of an airport in Qingdao.The vertical compressive performance of large-diameter embedded rock-filled piles was analyzed to clarify the load transfer law of large-diameter-filled piles.The results showed that the integrity of the test piles was good and the quality of the piles was reliable.The load-settlement(Q-s)curves of the test piles were all of slow-variable type,and there was a significant pressure-tight section at the beginning of loading,with a settlement of 10.31 mm at the top of the pile,and a minimum rebound rate of more than 50％.Under the maximum load,the characteristic value of the vertical compressive ultimate bearing capacity of each test pile was not less than 6480 kN.The vertical compressive bearing capacity of the test piles still has greater potential.The test piles all showed the characteristics of end-bearing friction piles.The axial force gradually decayed from the top of the pile to the end of the pile.The pile side friction resistance peak occurred in the moderately weathered mudstone segment,and the pile end resistance accounted for 10.55％-34.48％of the pile top load.
关键词
泥岩地基/大直径灌注桩/静载试验/桩身内力/桩侧摩阻力/桩端阻力Key words
mudstone foundation/large diameter cast-in-place pile/static load test/pile internal force/pile lateral friction resistance/pile end resistanc引用本文复制引用
基金项目
国家自然科学基金项目(51778312)
国家自然科学基金项目(51708316)
山东省自然科学基金重点项目(ZR2020KE009)
山东省博士后创新项目(201903043)
出版年
2024
NETL
NSTL
万方数据