(1 宁夏宁电电力设计有限公司, 银川 750001; 2 西安交通大学土木工程系, 西安 710054)

摘要: 微型桩因其受力性能好及施工优势逐渐应用于输电线路杆塔基础,但群桩基础承载性能的研究相对较少。基于黄土地基微型群桩现场静载试验,研究了桩数和桩间距对微型群桩抗拔承载性能的影响;并建立了精细化有限元模型,进行了极限承载力分析。 通过与试验结果对比,验证了有限元模型的合理性,在此基础上分析了桩间距、桩倾角对微型群桩抗拔承载性能的影响。 结果表明:随着桩数、桩间距及桩倾角增加,微型群桩抗拔承载力均表现出不同程度的提高。 结合试验和有限元分析可得黄土地基微型群桩的桩间距建议值 4d,桩倾角建议值 10°,群桩抗拔效应系数建议值 0. 80。

关键词: 微型群桩; 静载试验; 数值模拟; 抗拔承载性能; 桩间距; 桩倾角; 群桩效应

中图分类号:TU473 文献标志码:A 文章编号:1002-848X(2022)24-0120-06

DOI:10. 19701 / j. jzjg. 20211538

Study on uplift bearing capacity and group pile effect of micro-pile group in loess foundation

ZHANG Aijun1, FU Hongan1, WANG Jiajia2, WANG Xueping1, TIAN Shuai1, SUN Qing2

(1 Ningxia Ningdian Power Design Institute Co. , Ltd. , Ningxia 750001, China; 2 Department of Civil Engineering,Xi'an Jiaotong University, Xi’ an 710054, China)

Abstract: The micro-pile has gradually been applied to the foundation of transmission line tower due to its good mechanicalperformance and construction advantages, but the bearing performance of pile group is relatively little researched. Based onthe field static load test of the micro-pile group in loess foundation, the influence of the number of piles and the distancebetween the piles on the uplift bearing performance of the micro-pile group were studied. And a refined finite element modelwas established to carry out analysis of the ultimate bearing capacity. By comparing with the test results, the reasonablenessof the finite element model was verified, and on this basis, the influence of pile spacing and pile inclination angle on theuplift bearing performance of micro-pile group was analyzed. The results show that with the increase of the number of piles,pile spacing and pile inclination angle, the uplift bearing capacity of micro-pile groups shows different degrees ofimprovement. According to the results of experiment and numerical simulation, the recommended values of pile spacing,pile inclination angle and anti-pull effect coefficient of micro-pile group in loess foundation are 4d, 10° and 0. 80respectively.

Keywords:micro-pile group; static test; numerical simulation; uplift bearing capacity; pile spacing; pile inclination; pilegroup effect

∗国家自然科学基金(51978570)。

第一作者:张爱军,学士,高级工程师,主要从事输电线路杆塔基础设计工作,Email:zzz_70_70@ sohu. com。

[引用本文] 张爱军,付红安,王佳佳,等. 黄土地基微型群桩抗拔承载力及群桩效应研究[J]. 建筑结构,2022,52(24):120-125. ZHANG Aijun,FU Hongan,WANG Jiajia,et al. Study on uplift bearing capacity and group pile effect ofmicro-pile group in loess foundation[J]. Building Structure,2022,52(24):120-125.