边汉亮，马宇豪，张建伟，等.不同桩长对GFRP复合桩竖向承载性能影响研究［J］.河南理工大学学报（自然科学版），2024，43（2）：177-185.

BIAN H L，MA Y H，ZHANG J W，et al.Effect of different pile sizes on vertical bearing capacity of GFRP composite piles［J］.Journal of Henan Polytechnic University（Natural Science），2024，43（2）：177-185.

不同桩长对GFRP复合桩竖向承载性能影响研究

边汉亮1，马宇豪1，张建伟1，瑜璐1，樊亚龙2

1.河南大学 土木建筑学院，河南 开封 475004；2.中建七局第四建筑有限公司，陕西 西安 710000

摘要: 目的 探究不同桩长对玻璃纤维增强复合材料（GFRP）桩竖向承载性能的影响。方法 分别对普通钢筋混凝土（RC）桩和GFRP复合桩的竖向承载性能进行研究，开展室内模型实验，同时利用有限元软件模拟不同桩长对其竖向承载特性的影响。结果 模型试验中，GFRP复合桩的竖向承载力大于RC桩，在桩顶荷载6 kN时，GFRP复合桩侧摩阻力占桩顶荷载的34.1%，RC桩占24.7%，GFRP材料明显改变了桩身的粗糙程度，使桩身界面摩擦特性增强，从而在较高的竖向荷载作用下，产生较小的端阻力。有限元软件模拟中，与RC桩相比，GFRP布与土体的摩擦系数比混凝土与土体的摩擦系数大，有利于GFRP复合桩侧摩阻力的发挥，相同桩长的GFRP复合桩端阻力占比明显低于RC桩。对比桩长5，10，15 m，RC桩，侧摩阻力值占桩基极限承载力的35.69%，42.44%，50.54%，GFRP复合桩的桩身侧摩阻力分别占桩基极限承载力的42.44%，63.09%，75.69%，表明GFRP复合桩是通过增加侧摩阻力来提高竖向承载力的，且桩长越长，GFRP复合桩承载性能提升越明显。结论 相同桩长的GFRP复合桩竖向承载力明显高于RC桩；随着桩长增大，GFRP复合桩桩侧摩阻力的发挥效果更好，对应的桩基极限承载力越高，GFRP桩-土的界面摩擦特性发挥越理想。试验结果可为GFRP复合桩的竖向承载力设计提供理论参考。

关键词: GFRP复合桩；竖向承载性能；模型试验；压实度；摩擦系数

doi:10.16186/j.cnki.1673-9787.2022120033

基金项目:国家自然科学基金资助项目（51508163）；河南省研究生教育改革与质量提升工程项目（YJS2021JD13）

收稿日期: 2022/12/13

修回日期: 2023/03/21

出版日期:2024/03/25

Effect of different pile sizes on vertical bearing capacity of GFRP composite piles

BIAN Hanliang1，MA Yuhao1，ZHANG Jianwei1，YU Lu1，FAN Yalong2

1.School of Civil and Architectural Engineering，Henan University，Kaifeng 475004，Henan，China；2.The Fourth Construction Company Ltd of China Construction Seventh Engineering Bureau，Xi’an 710000，Shaanxi，China

Abstract: Objectives To explore the influence of pile length on the vertical bearing capacity of glass fiber reinforced composite piles （GFRP composite piles）. Methods A series of model tests were performed to investigate the vertical bearing capacity of ordinary reinforced concrete piles （RC pile） and GFRP composite piles，respectively. Simultaneously，the effect of pile length was analyzed through finite element analyses for the vertical bearing capacity. Results In the model tests，the vertical bearing capacity of GFRP composite piles was found to be greater than that of RC piles.When the pile top load is 6 kN，the lateral friction resistance of GFRP composite piles accounts for 34.1% of the pile top load，while RC piles account for 24.7%. GFRP material significantly changes the roughness of the pile body，enhances the interface friction characteristics of the pile body，and generates smaller end resistance under higher vertical loads. In finite element software simulation， compared with RC piles，the friction coefficient between GFRP fabric and soil is greater than that between concrete and soil，which is conducive to the development of lateral friction resistance of GFRP composite piles.The proportion of end resistance of GFRP composite piles with the same pile length is significantly lower than that of RC piles.Compared with RC piles with pile lengths of 5，10， and 15 meters，the lateral friction values of GFRP composite piles account for 35.69%，42.44%，and 50.54% of the ultimate bearing capacity of the pile.The lateral friction values of GFRP composite piles account for 42.44%，63.09%，and 75.69% of the ultimate bearing capacity of the pile，respectively. This indicates that GFRP composite piles improve their vertical bearing capacity by increasing lateral friction，and the longer the pile length， the more significant the improvement in the bearing performance of GFRP composite piles. Conclusions The vertical bearing capacity of GFRP composite piles with the same pile length is significantly higher than that of RC piles.With increasing length， the side friction of the GFRP composite pile increased， which led to the corresponding results：a higher ultimate bearing capacity in the pile foundation， and larger interface friction of GFRP composite pile-soil.The conclusions could provide some suggestions for the design of the vertical bearing capacity of GFRP composite piles.

Key words:GFRP composite pile；vertical bearing capacity；model test；compaction degree；friction coefficient