湿陷性黄土地基注浆花钢管桩加固承载力试验分析
Experimental Analysis on Bearing Capacity of Grouting Steel Pipe Pile Reinforcement for Collapsible Loess Foundation
董超 1汪过兵 2樊建祥 1王罗林 1董圣君 1杨婷婷1
作者信息
- 1. 甘肃省建材科研设计院有限责任公司,甘肃 兰州 730020
- 2. 西安理工大学 岩土工程研究所,陕西 西安 710048
- 折叠
摘要
针对黄土地基不均匀湿陷沉降变形的问题,采用注浆花钢管桩进行加固,并对湿陷性黄土地基注浆花钢管桩加固承载力进行分析.通过对 6 个独立基础下的 32 个采用Q235 级材料、直径为ø108、壁厚为8mm的花钢管桩进行注浆前后的静载试验.发现在同级荷载下,花钢管桩注浆后的变形较注浆前明显减小.沉降变形较未注浆前提高了 50.3%～92.83%,承载力提升了37%～114.5%.此外,还观察到注浆前后试验载荷增量ΔQ随桩长先增大后减小,桩长约为 11m时载荷增量ΔQ达到峰值,并给出黄土地基加固最佳经济点.提高加固完成后持续 6 个月的沉降观测显示,地基未发生明显继续沉降,表明加固效果显著.此成果也为湿陷性黄土地区工程结构的地基加固设计提供了科学的数据支持.
Abstract
In order to solve the problem of uneven wet subsidence settlement and deformation of loess foundation,an analysis is carried out on the reinforcement of collapsible loess foundation by grouting steel pipe pile.The stat-ic load test before and after grouting is carried out on 32 steel pipe piles with Q235 grade material,diameter of Ø108 and wall thickness of 8mm under six independent foundations.It is found that under the same level of load,the deformation of steel pipe piles after grouting is significantly reduced compared with that before grouting.The settlement deformation increases by 50.3%to 92.83%and the bearing capacity increases by 37%to 114.5%compared with that before grouting.In addition,it is also observed that the test load increment ΔQ before and af-ter grouting increases and then decreases with the pile length,and the load increment ΔQ peaks at a pile length of about 11 m.The optimum economic point for loess foundation reinforcement is found.The settlement observation lasting six months after the completion of the improvement and reinforcement shows that there is no obvious con-tinued settlement of the foundation,indicating that the reinforcement effect is remarkable.The results also provide scientific data support for the foundation reinforcement design of engineering structures in collapsible loess areas.
关键词
湿陷性黄土地基/注浆花钢管桩/地基加固/承载力Key words
collapsible loess foundation/grouting steel pipe pile/foundation reinforcement/bearing capacity引用本文复制引用
出版年
2024
NETL
NSTL
万方数据