Lateral bearing characteristics of inclined pile-cap system installed in sandy ground
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摘要: 通过开展室内模型试验，研究了砂土中斜桩-承台系统的水平承载特性，重点分析了桩身倾角及桩身抗弯刚度两个因素对桩顶水平位移、桩身弯矩分布的影响。利用有限元方法开展了与模型试验相对应的三维有限元分析，两者所得结果的对比表明所采用的有限元分析方法能较好地反映斜桩在水平荷载下的受力和变形特性。为了更好地与工程实际相对应，基于上述数值分析方法开展了原型尺寸的数值参数分析，考虑了桩体的弹塑性力学特性，探究土体弹性模量、桩身刚度以及桩身长度对斜桩-承台系统水平承载能力的影响。计算结果表明，相较于改变桩身的抗弯刚度，土体弹性模量的变化对斜桩-承台系统水平承载能力的影响更为显著；当桩长小于25 m（25倍桩径）时，桩长的增加能较明显降低桩顶水平位移响应，当桩长超过该值时，斜桩水平承载能力的提升效率下降。此外，基于试验数据开展了多元回归分析，获得了斜桩-承台系统桩顶水平位移的半经验预测公式，该公式的预测值与试验实测值及数值参数分析计算值的吻合度均较高，具有良好的适用性，有望能为砂土中斜桩工程的设计和分析提供一定的参考依据。Abstract: The lateral bearing characteristics of inclined pile-cap systems installed in sandy soil are comprehensibly studied via a series of laboratory model tests, and the influences of inclination angle and flexural rigidity of pile on the lateral displacement at pile top and the distribution of pile bending moment are analyzed. Based on the model tests, a suite of three-dimensional finite element analyses are performed, and the favorable comparison of the test and numerical results convinces the capability of the adopted finite element analysis procedure in replicating the stress and deformation characteristics of the inclined piles in the model tests. Subsequently, a number of numerical parametric analyses based on the prototype models are implemented, accounting for the elastic-plastic mechanical properties of the pile, as well as the variations in elastic modulus of soil, flexural rigidity and length of the pile. The analysis results show that the variation in the elastic modulus of soil has a more significant effect on the lateral bearing capacity of the inclined pile-cap system than the change in pile flexural rigidity. When the pile length is less than 25 times the pile diameter(D), the increase of pile length can effectively reduce the lateral displacement response at the pile top. Otherwise, increasing the pile length has negligible effects on enhancing the lateral performance of the inclined pile-cap system. Furthermore, the multivariate regression analysis is performed based on the test data of lateral displacement at pile top, from which a semi-empirical equation can be derived. The performance of this semi-empirical equation is favorably examined by both the relevant experimental data and the numerical parametric analysis results, which likely provides a useful reference for the design and analysis of the inclined pile-cap system in sandy ground.
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图 2 模型桩桩身应变片粘贴位置示意图
Figure 2. Schematic diagram of model pile instrumented with full-bridge strain gauges
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图 5 不同桩身倾角下荷载-桩顶水平位移曲线
Figure 5. Lateral load-displacement curves at pile top under different inclination angles of pile
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图 6 桩顶水平位移随桩身倾角的变化图
Figure 6. Variation of lateral displacement at pile top against inclination angle of pile
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图 7 不同桩身倾角下桩身弯矩分布曲线图
Figure 7. Distributions of bending moment of pile under different inclination angles
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图 8 不同桩身倾角下铝桩桩身剪力分布曲线图
Figure 8. Distributions of shear force for aluminum pile under.different inclination angles
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图 9 不同桩身抗弯刚度下荷载-桩顶水平位移变化曲线图
Figure 9. Lateral load-displacement curves of pile top under different flexural rigidities of pile
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图 10 桩顶水平位移随桩身抗弯刚度的变化图
Figure 10. Variation of lateral displacement at pile top against flexural rigidity of pile
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图 11 不同桩身抗弯刚度下斜桩桩身弯矩分布图
Figure 11. Distributions of bending moment of pile under different.flexural rigidities
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图 12 桩身弯矩最大值随桩身抗弯刚度变化图
Figure 12. Variation of maximum bending moment of pile against flexural rigidity
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图 13 桩顶水平位移实测值与预测值对比图
Figure 13. Measured versus predicted lateral displacements at pile top
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图 14 斜桩-承台-土系统的三维有限元模型图
Figure 14. Finite element mesh of the inclined pile-cap-soil system
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图 15 模型试验与数值计算所获桩基水平位移及弯矩对比图（倾角20°，铝桩）
Figure 15. Comparison of measured and computed pile-top lateral displacements and bending moments of pile (inclination angle 20°, aluminum pile)
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图 16 不同桩身倾角下桩身轴力分布图
Figure 16. Distributions of axial force of pile under different inclination angles
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图 17 不同桩身倾角下桩侧摩阻力分布图
Figure 17. Distributions of skin friction of pile under different inclination angles
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图 18 不同竖向荷载下水平荷载-桩顶位移曲线
Figure 18. Lateral load versus pile-top displacement curves under different vertical loads
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图 19 不同竖向荷载下桩身轴力分布图
Figure 19. Distributions of axial force of pile under different vertical loads
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图 20 不同竖向荷载下桩侧摩阻力分布图
Figure 20. Distributions of skin friction of pile under different vertical loads
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图 21 不同土体弹性模量下斜桩桩顶水平位移变化曲线
Figure 21. Variation of lateral load against pile-top displacement for inclined pile-cap system under different elastic moduli of soil
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图 22 不同桩身抗弯刚度下斜桩桩顶水平位移曲线
Figure 22. Variation of lateral load against pile-top displacement under different flexural rigidities of pile
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图 23 不同桩身长度下水平荷载-桩顶位移曲线
Figure 23. Lateral load versus pile-top displacement curves under different pile lengths
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图 24 原型尺寸斜桩桩顶水平位移计算值与预测值的对比图
Figure 24. Computed versus predicted lateral displacement at pile top for prototype inclined pile-cap-soil system
表 1 模型桩的尺寸、力学参数表
Table 1 Dimensions and mechanical parameters of model piles
名称 弹性模量/GPa 密度/(kg·m-3) 外径/mm 内径/mm 有机玻璃 3.2 180 20 — 铝 71.0 2700 20 — 钢 210.0 7900 20 16 
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表 2 试验方案列表
Table 2 Test schemes
组号 材料 编号 桩身倾角/(°) 外径/mm 内径/mm M1 有机玻璃 P11 0 20 — P12 10 20 — P13 20 20 — P14 30 20 — P15 45 20 — M2 铝 P21 0 20 — P22 10 20 — P23 20 20 — P24 30 20 — P25 45 20 — M3 钢 P31 0 20 16 P32 10 20 16 P33 20 20 16 P34 30 20 16 P35 45 20 16
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表 3 桩基-承台系统水平极限承载力
Table 3 Lateral ultimate bearing capacities of pile-cap system
材料 桩身倾角/(°) 水平极限承载力/N 建议水平极限承载力/N 位移梯度法 位移限制法 有机玻璃 0 45.5 96.5 45.5 10 71.0 122.0 71.0 20 96.5 173.0 96.5 30 122.0 — 122.0 45 173.0 — 173.0 铝 0 71 224 71 10 122 275 122 20 173 — 173 30 224 — 224 45 275 — 275 钢 0 173 275 173 10 224 377 224 20 377 479 377 30 428 530 428 45 479 — 479
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表 4 桩身倾斜角度对斜桩桩身最大弯矩的影响
Table 4 Influence of inclination angle of pile on maximum bending moment
编号 倾角/(°) 最大弯矩/(N·m) 相对直桩的减幅/% P11 0 15.29 — P12 10 14.17 7.3 P13 20 12.29 19.6 P14 30 9.99 34.7 P15 45 8.43 44.9 P21 0 22.70 — P22 10 19.80 12.8 P23 20 17.35 23.6 P24 30 15.67 30.9 P25 45 13.57 40.2 P31 0 37.94 — P32 10 35.84 5.5 P33 20 33.87 10.7 P34 30 32.59 14.1 P35 45 29.33 22.8
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表 5 承台和桩的计算参数表
Table 5 Computational parameters of caps and piles
名称 弹性模量/GPa 密度/(kg·m-3) 泊松比 有机玻璃桩 3.2 180 0.3 铝桩及承台 71 2700 0.2 钢桩及承台 124 7900 0.2
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表 6 地基土计算参数表
Table 6 Computational parameters of foundation soil
重度/(kN·m-3) 内摩擦角/(°) 弹性模量/MPa 泊松比 17.6 40.9 63 0.3
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[1] 郑刚, 何晓佩, 周海祚, 等. 基坑斜-直交替支护桩工作机理分析[J]. 岩土工程学报, 2019, 41(增刊1): 97-100. doi: 10.11779/CJGE2019S1025 ZHENG Gang, HE Xiaopei, ZHOU Haizuo, et al. Working mechanism of inclined-vertical retaining piles in excavations[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(S1): 97-100. (in Chinese) doi: 10.11779/CJGE2019S1025
[2] GUO L, ZHANG Z Q, WANG X B, et al. Stability analysis of transmission tower foundations in permafrost equipped with thermosiphons and vegetation cover on the Qinghai-Tibet Plateau[J]. International Journal of Heat and Mass Transfer, 2018, 121: 367-376. doi: 10.1016/j.ijheatmasstransfer.2018.01.009
[3] ZHENG G, YANG X Y, ZHOU H Z, et al. A simplified prediction method for evaluating tunnel displacement induced by laterally adjacent excavations[J]. Computers and Geotechnics, 2018, 95: 119-128. doi: 10.1016/j.compgeo.2017.10.006
[4] 吕凡任. 倾斜荷载作用下斜桩基础工作性状研究[D]. 杭州: 浙江大学, 2004. LÜ Fanren. Study on Behavior of Battered Piles under Inclined Load[D]. Hangzhou: Zhejiang University, 2004. (in Chinese)
[5] 王新泉, 陈永辉, 安永福, 等. 塑料套管现浇混凝土桩倾斜对承载性能影响的模型试验研究[J]. 岩石力学与工程学报, 2011, 30(4): 834-842. WANG Xinquan, CHEN Yonghui, AN Yongfu, et al. Model test study of effect of inclination on bearing behaviors of plastic tube cast-in-place concrete pile[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(4): 834-842. (in Chinese)
[6] SABBAGH T T, AL-SALIH O, AL-ABBOODI I. Experimental investigation of batter pile groups behaviour subjected to lateral soil movement in sand[J]. International Journal of Geotechnical Engineering, 2020, 14(7): 705-716. doi: 10.1080/19386362.2019.1585596
[7] MEYERHOF G G, YALCIN A S. Behaviour of flexible batter piles under inclined loads in layered soil[J]. Canadian Geotechnical Journal, 1993, 30(2): 247-256. doi: 10.1139/t93-021
[8] ZHANG L M, MCVAY M C, LAI P W. Centrifuge modelling of laterally loaded single battered piles in sands[J]. Canadian Geotechnical Journal, 1999, 36(6): 1074-1084. doi: 10.1139/t99-072
[9] HAZZAR L, HUSSIEN M N, KARRAY M. Numerical investigation of the lateral response of battered pile foundations[J]. International Journal of Geotechnical Engineering, 2017, 11(4): 376-392. doi: 10.1080/19386362.2016.1224030
[10] BAJAJ P, YADU L, CHOUKSEY S K. Study on vertical and batter piles subjected to lateral loads in different non-cohesive sub-soil conditions[J]. International Journal of Geotechnical Engineering, 2020, 14(6): 603-613. doi: 10.1080/19386362.2018.1564181
[11] KONG D S, DENG M X, LI Y Z. Experimental study on mechanical deformation characteristics of inclined and straight alternating pile groups[J]. Advances in Civil Engineering, 2020, 2020: 1-11.
[12] RAJASHREE S S, SITHARAM T G. Nonlinear finite-element modeling of batter piles under lateral load[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2001, 127(7): 604-612. doi: 10.1061/(ASCE)1090-0241(2001)127:7(604)
[13] 黄剑慧, 陈红兵, 刘杰伟, 等. 群桩中的斜桩受力分析与计算[J]. 广东土木与建筑, 2007, 14(8): 21-23. HUANG Jianhui, CHEN Hongbing, LIU Jiewei, et al. Force analysis and calculation of inclined piles in pile groups[J]. Guangdong Architecture Civil Engineering, 2007, 14(8): 21-23. (in Chinese)
[14] LING D, REN T, WANG Y. A p-y curve method for horizontal bearing characteristics of single batter pile in sands[J]. Rock Soil Mech, 2013, 34(1): 155-162.
[15] REESE L C, COX W R, KOOP F D. Analysis of laterally loaded piles in sand[C]//Proceedings of the Sixth Annual Offshore Technology Conference. Texas, 1974.
[16] 曹卫平, 吴奇兴, 夏冰, 等. 考虑上拔荷载影响的水平受荷斜桩p-y曲线[J]. 岩土工程学报, 2020, 42(7): 1189-1198. doi: 10.11779/CJGE202007002 CAO Weiping, WU Qixing, XIA Bing, et al. p-y curve of laterally loaded batter piles considering effect of uplift loads[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(7): 1189-1198. (in Chinese) doi: 10.11779/CJGE202007002
[17] 樊文甫. 水平受荷斜桩承载变形性状数值分析[D]. 西安: 西安建筑科技大学, 2016. FAN Wenfu. Numerical Analyses on the Behavior of Horizontally Loaded Batter Piles[D]. Xi'an: Xi'an University of Architecture and Technology, 2016. (in Chinese)
[18] 曹卫平, 葛欣. 水平受荷斜桩承载变形性状及荷载传递机理分析[J]. 西安建筑科技大学学报(自然科学版), 2017, 49(5): 624-629. CAO Weiping, GE Xin. Analyses of bearing capacity and load transfer mechanism of horizontally loaded batter piles[J]. Journal of Xi'an University of Architecture & Technology (Natural Science Edition), 2017, 49(5): 624-629. (in Chinese)
[19] 王恩钰, 周海祚, 郑刚, 等. 基坑倾斜桩支护的变形数值分析[J]. 岩土工程学报, 2019, 41(增刊1): 73-76. doi: 10.11779/CJGE2019S1019 WANG Enyu, ZHOU Haizuo, ZHENG Gang, et al. Numerical analyses of deformation of inclined pile-retained excavations[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(S1): 73-76. (in Chinese) doi: 10.11779/CJGE2019S1019
[20] 赵爽, 吴君涛, 张日红, 等. 砂土中斜桩单桩水平承载与变形特性数值分析[J]. 中南大学学报(自然科学版), 2022, 53(2): 579-588. ZHAO Shuang, WU Juntao, ZHANG Rihong, et al. Numerical analysis of horizontal bearing capacity and deflection behaviors of single batter pile in sand[J]. Journal of Central South University (Science and Technology), 2022, 53(2): 579-588. (in Chinese)
[21] 土工试验方法标准: GB/T 50123—2019[S]. 北京: 中国计划出版社, 2019. Standard for Soil Test Method: GB/T 50123—2019[S]. Beijing: China Planning Press, 2019. (in Chinese)
[22] 建筑基桩检测技术规范: JGJ 106—2014[S]. 北京: 中国建筑工业出版社, 2014. Technical Code for Testing of Building Foundation Piles: JGJ 106—2014[S]. Beijing: China Architecture & Building Press, 2014. (in Chinese)
[23] 袁志林, 段梦兰, 陈祥余, 等. 水平荷载下导管架平台桩基础的非线性有限元分析[J]. 岩土力学, 2012, 33(8): 2551-2560. YUAN Zhilin, DUAN Menglan, CHEN Xiangyu, et al. Nonlinear finite element analysis of jacket platform pile foundations under lateral loads[J]. Rock and Soil Mechanics, 2012, 33(8): 2551-2560. (in Chinese)
[24] 刘晋超, 熊根, 朱斌, 等. 砂土海床中大直径单桩水平承载与变形特性[J]. 岩土力学, 2015, 36(2): 591-599. LIU Jinchao, XIONG Gen, ZHU Bin, et al. Bearing capacity and deflection behaviors of large diameter monopile foundations in sand seabed[J]. Rock and Soil Mechanics, 2015, 36(2): 591-599. (in Chinese)
[25] 张磊, 周腾, 芮瑞, 等. 软黏土场地桩基桥墩系统地震损伤特性的三维有限元动力分析[J]. 振动与冲击, 2021, 40(23): 109-119. ZHANG Lei, ZHOU Teng, RUI Rui, et al. Three-dimensional finite element analyses of clay-pile-pier systems subjected to seismic motions[J]. Journal of Vibration and Shock, 2021, 40(23): 109-119. (in Chinese)
[26] 混凝土结构设计规范: GB 50010—2010[S]. 北京: 中国建筑工业出版社, 2011. Code for Design of Concrete Structures: GB 50010—2010[S]. Beijing: China Architecture & Building Press, 2011. (in Chinese)
[27] 郑刚, 王玉萍, 程雪松, 等. 基坑倾斜桩支护性能及机理大型模型试验研究[J]. 岩土工程学报, 2021, 43(9): 1581-1591. doi: 10.11779/CJGE202109002 ZHENG Gang, WANG Yuping, CHENG Xuesong, et al. Large-scale model tests on performance and mechanism of inclined retaining structures of excavations[J]. Chinese Journal of Geotechnical Engineering, 2021, 43(9): 1581-1591. (in Chinese) doi: 10.11779/CJGE202109002
[28] 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. http://www.cgejournal.com/cn/article/id/13062 ZHENG Gang, WANG Li. Effect of loading level and sequence of vertical and lateral load on bearing capacity of single pile[J]. Chinese Journal of Geotechnical Engineering, 2008, 30(12): 1796-1804. (in Chinese) http://www.cgejournal.com/cn/article/id/13062
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