黄土地基微型群桩抗拔承载力及群桩效应研究  

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

作　　者：张爱军 付红安 王佳佳 王学平 田帅 孙清[2] ZHANG Aijun;FU Hongan;WANG Jiajia;WANG Xueping;TIAN Shuai;SUN Qing(Ningxia Ningdian Power Design Institute Co.,Ltd.,Ningxia 750001,China;Department of Civil Engineering,Xi'an Jiaotong University,Xi’an 710054,China)

机构地区：[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

出　　处：《建筑结构》2022年第24期120-125,共6页Building Structure

基　　金：国家自然科学基金(51978570)。

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。The micro-pile has gradually been applied to the foundation of transmission line tower due to its good mechanical performance and construction advantages, but the bearing performance of pile group is relatively little researched. Based on the field static load test of the micro-pile group in loess foundation, the influence of the number of piles and the distance between the piles on the uplift bearing performance of the micro-pile group were studied. And a refined finite element model was established to carry out analysis of the ultimate bearing capacity. By comparing with the test results, the reasonableness of the finite element model was verified, and on this basis, the influence of pile spacing and pile inclination angle on the uplift 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 of improvement. 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 0.80 respectively.

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 

分 类 号：TU473[建筑科学—结构工程]