芯桩承载扩体预制桩的荷载传递计算分析

张浩; 赵宇; 王中; 刘维正

doi:10.11779/CJGE20230745

芯桩承载扩体预制桩的荷载传递计算分析 English Version

张浩^{1, 2,},
赵宇³,
王中¹,
刘维正^{2, 4, ,}

1.
郑州大学土木工程学院, 河南郑州 450001
2.
高速铁路建造技术国家工程研究中心, 湖南长沙 410075
3.
安徽省交通规划设计研究总院股份有限公司, 安徽合肥 230088
4.
中南大学土木工程学院, 湖南长沙 410075

基金项目:

国家自然科学基金项目 52078500

高速铁路建造技术国家工程研究中心开放基金项目 HSR202102

河南省重点研发与推广专项项目（科技攻关） 232102240026

河南省交通运输厅科技项目 2021-2-14

河南省住房与城乡建设科技计划项目 HNJS-2022-K45

详细信息

作者简介:
张浩(1985—)，男，博士，副教授，主要从事地基基础与支护工程方面的研究工作。E-mail：tmzhanghao@zzu.edu.cn

通讯作者:
刘维正, E-mail: liuwz2011@csu.edu.cn

中图分类号: TU473.1
计量
- 文章访问数: 349
- HTML全文浏览量: 45
- PDF下载量: 104
出版历程
- 收稿日期: 2023-08-02
- 网络出版日期: 2024-06-04
- 刊出日期: 2024-11-30

Calculation and analysis of load transfer behaviors of reamed precast concrete piles under bearing of core piles

ZHANG Hao^{1, 2,},
ZHAO Yu³,
WANG Zhong¹,
LIU Weizheng^{2, 4, ,}

1.
School of Civil Engineering, Zhengzhou University, Zhengzhou 450001, China
2.
National Engineering Research Center of High-speed Railway Construction Technology, Changsha 410075, China
3.
Anhui Transport Consulting & Design Institute Co., Ltd., Hefei 230088, China
4.
School of Civil Engineering, Central South University, Changsha 410075, China

摘要

摘要: 扩体预制桩由内芯预制桩和外围扩体材料固结体组成，竖向承载时涉及到芯桩、外围扩体和周围土三者的相互作用，荷载传递机制十分复杂。针对芯桩承载全长扩体预制桩的荷载传递特点，采用弹性-破坏模型模拟芯桩-扩体界面相互作用，理想弹塑性模型模拟扩体-土界面非线性相互作用，并综合考虑内、外两界面剪切特性发挥及其耦合作用，构建了芯桩承载扩体预制桩荷载传递计算分析模型，给出了简化计算方法。与工程实例的对比，验证了方法的可靠性，并对芯桩承载扩体预制桩荷载传递规律进行分析。结果表明：外围扩体可有效地将芯桩荷载传递至周围土，扩体厚度和刚度的增加可提升整体承载性能，但较厚的扩体会制约芯桩承载能力的发挥，扩体刚度的提高有利于芯桩与扩体的共同作用。工程设计与实践中，可通过调整扩体厚度和性能来调配芯桩、扩体和周围土的相互作用。
- 扩体预制桩 /
- 荷载传递 /
- 承载性能 /
- 计算模型 /
- 植入桩
Abstract: The reamed precast concrete (RPC) pile is composed of core precast concrete (PC) pile and peripheral reamed material condensate, and its load transfer behaviors are very complex due to the cooperative bearing mechanism of the core pile, reamed material and surrounding soil. To investigate the load transfer behaviors of the whole reamed precast concrete pile under bearing of the core pile, an elastic-failure model is adopted to characterize the interaction performance of the core pile-reamed body interface, and an ideal elastic-plastic model is used to simulate the nonlinear interaction between reamed body and soil interface. Considering the shear characteristics of the inner and outer interfaces and their coupling effects, a load transfer model is established for the RPC pile under bearing of the core pile, and the computational method is further provided. The applicability of the proposed method is examined by comparing the results with those of the field tests, and the load transfer behaviors of the RPC pile is discussed. The results indicate that the peripheral reamed body can effectively transfer the core pile load to the surrounding soil. Increasing the thickness and stiffness of the reamed body can improve the bearing performance of the composite pile. However, thicker reamed body may also restrict the play of the bearing capacity of the core pile. Increasing the stiffness of the reamed body is conducive to the joint action of the core pile and peripheral reamed body. In engineering design and practice, the interaction between core pile, reamed body and surrounding soil can be coordinated by adjusting the thickness and performance of the reamed body.
- reamed precast concrete pile /
- load transfer /
- bearing performance /
- computational model /
- planted pile

HTML全文

图 1 承载变形机制示意图

Figure 1. Diagrammatic sketch of bearing mechanism

下载: 全尺寸图片幻灯片

图 2 界面模型示意图

Figure 2. Diagrammatic sketch of interface model

下载: 全尺寸图片幻灯片

图 3 单元体受力变形示意图

Figure 3. Diagrammatic sketch of forces and deformations on elements

下载: 全尺寸图片幻灯片

图 4 扩体预制桩-土相互作用模式

Figure 4. Reamed precast pile-soil interaction model

下载: 全尺寸图片幻灯片

图 5 实测与计算沉降-荷载曲线对比

Figure 5. Comparison between measured and calculated curves of displacement-load

下载: 全尺寸图片幻灯片

图 6 芯桩轴力与桩身压缩量的实测与计算结果对比

Figure 6. Comparison of measured and calculated axial force of core pile and settlement compression of pile

下载: 全尺寸图片幻灯片

图 7 界面剪切试验示意图

Figure 7. Diagrammatic sketch of interface shear tests

下载: 全尺寸图片幻灯片

图 8 界面剪切试验结果

Figure 8. Results of interface shear tests

下载: 全尺寸图片幻灯片

图 9 实测值与计算值对比

Figure 9. Comparison between measured and calculated values

下载: 全尺寸图片幻灯片

图 10 扩体预制桩桩身轴力

Figure 10. Axial forces of reamed precast pile

下载: 全尺寸图片幻灯片

图 11 扩体预制桩界面阻力

Figure 11. Interfacial resistances of reamed precast pile

下载: 全尺寸图片幻灯片

图 12 不同扩径情况下桩身轴力

Figure 12. Axial forces under different reaming diameters

下载: 全尺寸图片幻灯片

图 13 不同扩体材料情况下桩身轴力

Figure 13. Axial forces under different peripheral materials

下载: 全尺寸图片幻灯片

表 1 试桩沉降压缩量对比分析

Table 1 Comparative analysis of settlement compression of pile

计算分析	桩顶荷载/kN	桩顶沉降/mm	桩身压缩/mm	桩端沉降/mm	桩身压缩沉降比/%
试桩^[17]	2200	10.23	2.82	7.41	27.57
本文方法	2200	9.83	2.73	7.10	27.76

下载: 导出CSV

表 2 土层主要物理力学指标

Table 2 Physico-mechanical indexes of soil layers

土层	h/ m	γ/ (kN·m^-3)	c/ kPa	ϕ/ (°)	E_s1-2/ MPa	f_sk/ kPa
②粉土	6.1	19.3	20.6	10.2	7.50	140
②1粉质黏土	2.4	19.1	34.6	12.2	8.59	180
③粗砂	2.8	—	—	—	—	250
⑦1全风化角砾岩	—	—	51.9	12.5	—	350

下载: 导出CSV

参考文献(17)

[1]	根固混凝土桩技术规程: T/CCES 35—2022[S]. 北京: 中国建筑工业出版社, 2022. Technical Specification for Root-Reinforced Concrete Piles: T/CCES 35—2022[S]. Beijing: China Architecture & Building Press, 2022. (in Chinese)
[2]	周同和, 张浩, 郜新军, 等. 根固桩与扩体桩[M]. 北京: 中国建筑工业出版社, 2022. ZHOU Tonghe, ZHANG Hao, GAO Xinjun, et al. Root-Fixed Pile and Enlarged Pile[M]. Beijing: China Architecture & Building Press, 2022. (in Chinese)
[3]	JAMSAWANG P, BERGADO D, BANDARI A, et al. Investigation and simulation of behavior of stiffened deep cement mixing (SDCM) piles[J]. International Journal of Geotechnical Engineering, 2008, 2(3): 229-246. doi: 10.3328/IJGE.2008.02.03.229-246
[4]	WONGLERT A, JONGPRADIST P, JAMSAWANG P, et al. Bearing capacity and failure behaviors of floating stiffened deep cement mixing columns under axial load[J]. Soils and Foundations, 2018, 58(2): 446-461. doi: 10.1016/j.sandf.2018.02.012
[5]	WANG A H, ZHANG D W, DENG Y G. A simplified approach for axial response of single precast concrete piles in cement-treated soil[J]. International Journal of Civil Engineering, 2018, 16(10): 1491-1501. doi: 10.1007/s40999-018-0341-9
[6]	俞建霖, 徐山岱, 杨晓萌, 等. 刚性基础下砼芯水泥土桩复合地基沉降计算[J]. 中南大学学报(自然科学版), 2020, 51(8): 2111-2120. YU Jianlin, XU Shandai, YANG Xiaomeng, et al. Settlement calculation of composite foundation with concretecored DCM pile under rigid foundation[J]. Journal of Central South University (Science and Technology), 2020, 51(8): 2111-2120. (in Chinese)
[7]	张浩, 刘维正, 何利超, 等. 引扩孔灌浆扩体预制桩竖向承载变形的简化计算[J]. 铁道科学与工程学报, 2022, 19(1): 120-128. ZHANG Hao, LIU Weizheng, HE Lichao, et al. Simplified calculation method for vertical bearing deformation of pre-bored grouting reamed precast pile[J]. Journal of Railway Science and Engineering, 2022, 19(1): 120-128. (in Chinese)
[8]	ZHU S M, CHEN C F, CAI H, et al. Analytical modeling for the load-transfer behavior of stiffened deep cement mixing (SDCM) pile with rigid cap in layer soils[J]. Computers and Geotechnics, 2022, 144: 104618. doi: 10.1016/j.compgeo.2021.104618
[9]	郜新军, 王剑博, 张浩, 等. 水泥砂浆扩体预制桩竖向承载特性试验研究[J]. 岩土工程学报, 2023, 45(3): 634-643. doi: 10.11779/CJGE20220005 GAO Xinjun, WANG Jianbo, ZHANG Hao, et al. Field tests on bearing behaviors of cement mortar-expanded precast piles[J]. Chinese Journal of Geotechnical Engineering, 2023, 45(3): 634-643. (in Chinese) doi: 10.11779/CJGE20220005
[10]	顾士坦, 施建勇, 王春秋, 等. 劲性搅拌桩芯桩荷载传递规律理论研究[J]. 岩土力学, 2011, 32(8): 2473-2478. GU Shitan, SHI Jianyong, WANG Chunqiu, et al. Theoretical study of core pile load transfer regularity of reinforced mixing pile[J]. Rock and Soil Mechanics, 2011, 32(8): 2473-2478. (in Chinese)
[11]	任连伟, 刘希亮, 王光勇. 高喷插芯组合单桩荷载传递简化计算分析[J]. 岩石力学与工程学报, 2010, 29(6): 1279-1287. REN Lianwei, LIU Xiliang, WANG Guangyong. Simplified calculation and analysis of load transfer behavior for single JPP[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(6): 1279-1287. (in Chinese)
[12]	ZHOU J J, GONG X N, WANG K H, et al. A simplified nonlinear calculation method to describe the settlement of pre-bored grouting planted nodular piles[J]. Journal of Zhejiang University: Science A, 2017, 18(11): 895-909. doi: 10.1631/jzus.A1600640
[13]	王忍. 软土地基中柔性桩-土界面接触特性研究[D]. 株洲: 湖南工业大学, 2017. WANG Ren. Research on Contact Performance of Interface between Flexible Column and Soil in Soft Clay[D]. Zhuzhou: Hunan University of Technology, 2017. (in Chinese)
[14]	俞建霖, 徐嘉诚, 周佳锦, 等. 混凝土芯水泥土复合桩混凝土-水泥土界面摩擦特性试验研究[J]. 土木工程学报, 2022, 55(8): 93-104, 117. YU Jianlin, XU Jiacheng, ZHOU Jiajin, et al. Experimental study on frictional capacity of concrete-cemented soil interface of concrete-cored cemented soil column[J]. China Civil Engineering Journal, 2022, 55(8): 93-104, 117. (in Chinese)
[15]	COOKE R W, PRICE G, TARR K. Jacked piles in London Clay: a study of load transfer and settlement under working conditions[J]. Géotechnique, 1979, 29(2): 113-147. doi: 10.1680/geot.1979.29.2.113
[16]	RANDOLPH M F, WROTH C P. Analysis of deformation of vertically loaded piles[J]. Journal of the Geotechnical Engineering Division, 1978, 104(12): 1465-1488. doi: 10.1061/AJGEB6.0000729
[17]	梁善斋. 水泥土复合管桩竖向承载特性现场试验[J]. 岩土工程学报, 2021, 43(增刊2): 280-283. doi: 10.11779/CJGE2021S2065 LIANG Shanzhai. Field test of vertical bearing characteristics of cement-soil composite pipe pile[J]. Chinese Journal of Geotechnical Engineering, 2021, 43(S2): 280-283. (in Chinese) doi: 10.11779/CJGE2021S2065