张建伟, 杨森, 瑜璐,等.阶梯型变截面桩水平承载机理研究[J].河南理工大学学报（自然科学版）,2025,44(2):176-185.

ZHANG J W, YANG S, YU L, et al.Study on the horizontal bearing mechanism of stepped variable cross-section piles[J].Journal of Henan Polytechnic University(Natural Science) ,2025,44(2):176-185.

阶梯型变截面桩水平承载机理研究

张建伟1,2, 杨森1, 瑜璐1, 赫山林1, 张龑3

1.河南大学 土木建筑学院，河南 开封  475004；2.开封市特殊土改性与修复工程技术研究中心，河南 开封  475004；3.黄河勘测规划设计研究院有限公司，河南 郑州  450003

摘要: 目的 为探究粉砂地基中刚性与弹性阶梯型变截面桩的水平承载机理和变径因素对水平承载性能的影响，进行室内和数值模拟实验。   方法 分别对刚、弹性阶梯型变截面桩和常截面桩进行水平加载，并利用有限元软件建立不同变径比和变径长度的数值模型。   结果 研究结果表明，下半段桩径减小阶梯型变截面形式对弹性桩的水平承载性能影响较小，考虑材料利用率情况下，刚性阶梯型变截面桩的单位体积水平承载力比常截面桩提高6.4%，弹性阶梯型变截面桩提升33.28%；水平荷载相同条件下，刚性阶梯型变截面桩的浅层土抗力大于常截面桩的，弹性阶梯型变截面桩的浅层土抗力小于弹性常截面桩的；阶梯型变截面桩的水平承载力随变径比和变径长度的增加而增大，单位体积水平承载力随变径比增加而减小。变径比为0.8，变径长度占比为50%时，弹性阶梯型变截面桩的水平承载力接近于弹性常截面桩；与弹性常截面桩相比，当弹性阶梯型变截面桩变径比为0.8，变径长度占比为40%时，单位体积水平承载力提升最大。   结论 与常截面桩相比，阶梯型变截面桩的单位水平承载力更高，合理设置变径长度和变径比可以节约成本。研究结果为实际工程中阶梯型变截面桩的应用提供参考。 

关键词:粉砂地基;阶梯型变截面桩;水平承载机理;变径比;有限元分析

doi:10.16186/j.cnki.1673-9787.2023110005

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资助项目（YJS2021JD13）；河南省自然科学基金资助项目（232300420292）；河南大学研究生英才计划资助项目（SYLYC2023060）

收稿日期:2023/11/04

修回日期:2024/01/05

出版日期:2025-03-05

Study on the horizontal bearing mechanism of stepped variable cross-section piles

ZHANG Jianwei1,2, YANG Sen1, YU Lu1, HE Shanlin1, ZHANG Yan3

1.School of Civil Engineering and Architecture， Henan University， Kaifeng  475004， Henan， China；2.Kaifeng Technology Research Center of Engineering on Soil Modification and Restoration， Kaifeng  475004， Henan， China；3.Yellow River Engineering Consulting Co.， Ltd.， Zhengzhou  450003， Henan， China

Abstract: Objectives This study aims to investigate the horizontal bearing mechanism of rigid and elastic stepped variable cross-section piles in silty sand foundations and to evaluate the impact of variable diameter factors on horizontal bearing capacity. Indoor and numerical simulation experiments were conducted.   Methods Horizontal loading tests were performed on rigid and elastic stepped variable cross-section piles as well as constant cross-section piles. Finite element software was used to develop numerical models with different variable diameter ratios and lengths for analysis.   Results The results indicate that reducing the diameter of the lower half of the pile， using the stepped variable cross-section design， has a minimal impact on the horizontal bearing capacity of the elastic piles. Considering material efficiency， the unit volume horizontal bearing capacity of the rigid stepped variable cross-section pile is 6.4% higher than that of the constant cross-section pile， while the elastic stepped variable cross-section pile shows a 33.28% increase. Under the same horizontal load conditions， the shallow soil resistance of the rigid stepped variable cross-section pile is higher than that of the constant cross-section pile， while the shallow soil resistance of the elastic stepped variable cross-section pile is lower than that of the elastic constant cross-section pile. The horizontal bearing capacity of the stepped variable cross-section pile increases with higher variable diameter ratios and lengths， while the unit volume horizontal bearing capacity decreases as the variable diameter ratio increases. When the variable diameter ratio is 0.8 and the variable diameter length is 50% of the pile length， the horizontal bearing capacity of the elastic stepped variable cross-section pile is close to that of the elastic constant cross-section pile. Compared to the elastic constant cross-section pile， the unit volume horizontal bearing capacity is maximized when the variable diameter ratio is 0.8 and the variable diameter length is 40% of the pile length.   Conclusions The unit horizontal bearing capacity of the stepped variable cross-section pile is higher than that of the constant cross-section pile. Reasonable optimization of the variable diameter length and ratio can help reduce project costs. The findings provide valuable insights for the application of stepped variable cross-section piles in practical engineering. 

Key words:silty sand foundation;stepped variable cross-section pile;horizontal bearing mechanism;model test;finite element analysis