组合荷载下考虑摩擦增强效应的基桩承载性能研究

兰州理工大学学报 ›› 2023, Vol. 49 ›› Issue (3): 115-120.

组合荷载下考虑摩擦增强效应的基桩承载性能研究

宋小春^*1,*, 段新国², 黄瑞¹, 朱彦鹏²

1.甘肃第六建设集团股份有限公司, 甘肃兰州 730050;
2.兰州理工大学土木工程学院, 甘肃兰州 730050

收稿日期:2022-11-05 出版日期:2023-06-28 发布日期:2023-07-07
通讯作者: 宋小春(1960-),男,甘肃静宁人,高级工程师. Email:1761139606@qq.com
基金资助:
甘肃省住房和城乡建设厅科研项目(JK2020-06),甘肃建投科技项目(JTKE-2020-08)

Study on bearing capacity of foundation pile considering friction enhancement effect under combined load

SONG Xiao-chun¹, DUAN Xin-guo², HUANG Rui¹, ZHU Yan-peng²

1. Gansu Sixth Construction Group Co. Ltd., Lanzhou 730050, China;
2. School of Civil Engineering, Lanzhou Univ. of Tech., Lanzhou730050, China

Received:2022-11-05 Online:2023-06-28 Published:2023-07-07

摘要/Abstract

摘要： 目前规范采用的单一荷载分别作用再进行效果叠加的基桩承载能力分析方法,忽视了竖向荷载和水平荷载之间的耦合作用,不符合基桩的真实受力情况.为探讨组合荷载作用下基桩承载机制,基于弹性地基梁理论,考虑荷载影响的摩擦增强效应和位移增量,推导出摩擦力产生的抵抗弯矩表达式,并建立了基桩的位移-内力控制方程.采用Mathematica软件对既有案例进行分析,验证了理论的正确性.研究结果表明:在组合荷载作用下,当基桩处于小变形时考虑摩擦增强效应和位移增量计算得到的变形与内力具有很好的计算精度;随着桩身自由段的增长,计算得到的弯矩相对误差仍控制在10%以下.研究成果为基桩承载能力的计算提供了新的思路,丰富了组合荷载作用下基桩承载性能分析理论.

关键词: 摩擦增强效应, 位移增量, 组合荷载, 基桩承载力, 抵抗弯矩

Abstract: At present, the pile bearing capacity analysis method of single load acting separately and then effect superimposing is adopted in the code, which ignores the coupling between vertical and horizontal loads and does not conform to the real stress situation. In order to investigate the bearing mechanism of foundation pile under combined load, based on the beam theory of elastic foundation, the expression of resistance moment caused by friction was derived considering the friction enhancement effect and displacement increment under load, and the displacement-internal force control equation of foundation pile was established. Use Mathematica software to analyze the existing cases and verify the correctness of the theory. The results show that under the condition of small deformation, considering the friction enhancement effect and displacement increment, the calculation accuracy of pile deformation and internal force is very good, and the accuracy is greatly affected by the change of calculation parameters. The results show that the deformation and internal force calculated by considering the friction enhancement effect and displacement increment have good accuracy when the pile is in small deformation under combined load. With the increase of the free section of the pile, the relative error of the calculated bending moment is still less than 10%. The research results provide a new idea for the calculation of bearing capacity of foundation piles, and enrich the analysis theory of bearing capacity of foundation piles under combined loads.

Key words: friction enhancement effect, displacement increment, combined load, bearing capacity of foundation pile, resisting moment

中图分类号:

TU311
P315.9

宋小春, 段新国, 黄瑞, 朱彦鹏. 组合荷载下考虑摩擦增强效应的基桩承载性能研究[J]. 兰州理工大学学报, 2023, 49(3): 115-120.

SONG Xiao-chun, DUAN Xin-guo, HUANG Rui, ZHU Yan-peng. Study on bearing capacity of foundation pile considering friction enhancement effect under combined load[J]. Journal of Lanzhou University of Technology, 2023, 49(3): 115-120.

参考文献

[1] 赵春风,刘丰铭,邱志雄,等.砂土中竖向和水平荷载共同作用下的单桩承载特性研究[J].岩土工程学报,2015,37(1):183-190.
[2] 皇甫明,王幼青,张军.纵横向荷载作用下桩的工作性状研究[J].哈尔滨工业大学学报,2003,35(6):743-746.
[3] 冯凯,木林隆,张静,等.竖向荷载对砂土中大直径桩水平加载反应的影响[J].地下空间与工程学报,2015,11(S1):53-58.
[4] 梁发云,廖晨聪,毛磊,等.竖向-水平荷载联合作用下单桩性状模型试验研究 [J].建筑结构,2013,43(6):92-94+98.
[5] 陈正,刘宇,梅国雄.既有竖向荷载对微型桩水平承载特性的影响[J].南京工业大学学报(自然科学版),2011,33(1):101-106.
[6] 郑刚,王丽.竖向及水平荷载加载水平、顺序对单桩承载力的影响[J].岩土工程学报,2008,30(12):1796-1804.
[7] KARTHIGEYAN S,RAMAKRISHNA V,RAJAGOPAL K.Interaction between vertical and lateral loads on the response of piles in soft clays [C]//Proceedings of the 16th International Conference on Soil Mechanics and Geotechnical Engineering.IOS Press,2005:1997-2000.
[8] RAJAGOPAL K,KARTHIGEYAN S.Influence of combined vertical and lateral loading on the lateral response of piles[J].International association for computer methods and advances in geomechanics (IACMAG),2008:3272-3282.
[9] ANAGNOSTOPOULOS C,GEORGIADIS M.Interaction of axial and lateral pile responses[J].Journal of Geotechnical Engineering,1993,119(4):793-798.
[10] 横山幸满. 桩结构物的计算方法和计算实例 [M].北京:中国铁道出版社,1984.
[11] 竺明星,戴国亮,龚维明,等.水平荷载下桩身侧阻抗力矩的作用机制与计算模型研究 [J].岩土力学,2019,40(7):2593-2607+2662.
[12] 张磊,龚晓南,俞建霖.纵横荷载下单桩地基反力法的半解析解[J].哈尔滨工业大学学报,2011,43(6):96-100.
[13] 木林隆,康兴宇,李婉.砂土地基中V-H-M组合荷载下单桩分析方法研究[J].岩土工程学报,2017,39(S2):153-156.
[14] 竺明星,龚维明,何小元,等.纵横向受荷基桩变形内力的矩阵传递解[J].岩土力学,2014,35(11):3281-3288.
[15] ASHOUR M,NORRIS G M.Laterally and axially loaded deep foundation systems computer program DFSAP final report [R].Washington: Washington State Department of Transportation,2006.
[16] 中交第三航务工程勘察设计院有限公司.港口工程桩基规范: JTS 167—4—2012 [S].北京:人民交通出版社,2012.
[17] COX W R,REESE L C,GRUBBS B R.Field testing of laterally loaded piles in sand[C]//Proceedings of the 6th Annual Offshore Technology Conference.Houston:Texas,1974:459-472.
[18] BRINKGREVE R B J.PLAXIS user’s manual-version 8[M].Rotterdam,the Netherlands:A.A.Balkema,2002.
[19] LIANG F,ZHANG H,YANG K.A variational solution for nonlinear response of laterally loaded piles with elasto-plastic winkler spring model[J].KSCE Journal of Civil Engineering,2015,19(1):74-80.
[20] 赵明华. 倾斜荷载下基桩的受力研究 [D].长沙:湖南大学,2001.
[21] 中国建筑科学研究院.建筑桩基技术规范:JGJ 94-2008 [S].北京:中国建筑工业出版社,2008.