夏季工况下正常服役地热能源桩承载性能原位试验研究

doi:10.13722/j.cnki.jrme.2020.0858

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (1549 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要正确认识正常服役地热能源桩的承载性能，能有效促进其理论和设计方法的研究，为其安全性评判提供依据。为探明正常使用状态下地热能源桩的工作机制，结合现场原位试验，研究桩顶完全约束条件下静钻根植桩的承载特性。在52 m静钻根植桩桩身和桩侧埋设光纤光栅传感器(应变、温度、压力)，研究地热能源桩正常运行时的桩身和土体温度、桩身轴向应力和应变、桩周径向压力等变化规律。试验结果表明，加热14 d后换热系统达到稳定状态，桩身平均温度升高15.8 ℃，沿深度呈两端低中部高的分布形式，温度影响范围在2～4倍桩径。桩周径向附加应力与温度变化呈直线分布，最大拟合系数(0.861倍桩长深处)为0.014 MPa/℃。轴向附加应力与温度变化量也呈线性相关，3.05 m(0.059倍桩长深)处最大线性拟合系数达0.3 MPa/℃。附加桩侧摩阻力表现为两端小中部大，最大值位于(0.649～0.861)倍桩长深度范围。试验桩桩顶受到完全约束，中性点位于桩顶，桩身没有附加负摩阻力，因此正常服役地热能源桩的承载性能与桩顶约束条件密切相关。建筑荷载+温度共同作用下最大桩顶荷载为1 954 kN，仅为桩极限承载力的42.5%，不影响桩的安全性。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	方鹏飞1
	2
	高翔3
	娄扬3
	张日红4
	谢新宇3
	王忠瑾1
	2
	朱大勇1
	2

关键词 ：桩基础, 地热能源桩, 完全约束, 静钻根植桩, 现场试验, 夏季工况

Abstract：Understanding the bearing behavior of geothermal energy piles in natural service will help researches in theory and design method，and provide evidence for safety assessment. A pile-loading field test for static drill rooted geothermal energy piles(SDRGEP) was undertaken to investigate the working mechanism of the piles in service under temperature cycles. In a SDRGEP of 52 m depth，the fiber bragg grating(FBG) sensors(including strain，stress and temperature) were buried to measure the temperatures of the pile and the surrounding soil，the mobilized axial and radial stresses and strains of the pile，the shaft resistance，etc. Test results show that，after heating of 14 d，the heat exchanging system reaches a stable state and the average temperature of the pile is raised by 15.8 ℃ with a distribution of low in middle and high at both ends and an influence range of 2 to 4 times of the pile radius. It is also found that the relationships of both the mobilized radial stress and the mobilized axial stress with the temperature are linear，with maximum fitting gradients of 0.014 MPa/℃ at 0.86 times of the pile length and 0.3 MPa/℃ at 3.05 m depth respectively. The mobilized shaft resistance first increases and then decreases with the depth，reaching the maximum value at 0.649–0.861 times of the pile length. Whilst the pile head is fully constrained，the null point locates at the pile top and there is no negative side shear stress along the pile，showing that the bearing capacity of the pile is closely related to the constraint of the pile head. The maximum axial force at the pile head is 1 954 kN under the mechanical and thermal loads，which is only 42.5% of the ultimate bearing capacity of the pile，indicating that the pile is safe.

Key words： pile foundation geothermal energy piles fully constraint on pile top static drill rooted piles in-situ test summer condition

引用本文:

方鹏飞1，2，高翔3，娄扬3，张日红4，谢新宇3，王忠瑾1，2，朱大勇1，2. 夏季工况下正常服役地热能源桩承载性能原位试验研究[J]. 岩石力学与工程学报, 2021, 40(5): 1032-1042.
FANG Pengfei1，2，GAO Xiang3，LOU Yang3，ZHANG Rihong4，XIE Xinyu3，WANG Zhongjin1，2，ZHU Dayong1，2. Field test on the bearing behaviors of geothermal energy piles in natural service under the summer condition. , 2021, 40(5): 1032-1042.

链接本文:

http://rockmech.whrsm.ac.cn/CN/10.13722/j.cnki.jrme.2020.0858 或 http://rockmech.whrsm.ac.cn/CN/Y2021/V40/I5/1032

[27]	YOU S，CHENG X，GUO H，et al. Experimental study on structural response of CFG energy piles[J]. Applied Thermal Engineering，2016，96：640-651.
[13]	LORIA A F R，LALOUI L. Thermally induced group effects among energy piles[J]. Géotechnique，2016，66(12)：1-20.
[1]	BRANDL H. Energy foundations and other thermo-active ground structures[J]. Géotechnique，2006，56(2)：81-122.
[9]	郭易木，钟鑫，刘松玉，等. 自由约束条件下分层地基中 PHC 能源桩热力响应原型试验研究[J]. 岩石力学与工程学报，2019，38(3)：582-590.(GUO Yimu，ZHONG Xin，LIU Songyu，et al. Prototype experimental investigation on the thermo-mechanical behaviors of free constrained full-scale PHC energy piles in multi-layer strata[J]. Chinese Journal of Rock Mechanics and Engineering，2019，38(3)：582-590.(in Chinese))
[12]	WANG B，BOUAZZA A，SINGH R M，et al. Posttemperature Effects on Shaft Capacity of a Full-Scale Geothermal Energy Pile[J]. Journal of Geotechnical and Geoenvironmental Engineering，2015，141(4)：04014125.
[14]	周佳锦，龚晓南，王奎华，等. 静钻根植竹节桩抗压承载性能[J]. 浙江大学学报：工学版，2014，48(5)：835-842.(ZHOU Jiajin，GONG Xiaonan，WANG Kuihua，et al. Bearing capacity and load transfer mechanism of static drill rooted nodular piles[J]. Journal of Zhejiang University：Engineering Science，2014，48(5)：835-842.(in Chinese))
[3]	刘汉龙，孔纲强，吴宏伟. 能量桩工程应用研究进展及PCC能量桩技术开发[J]. 岩土工程学报，2014，36(1)：176-181.(LIU Hanlong，KONG Gangqiang，WANG Hongwei. Applications of energy piles and technical development of PCC energy piles[J]. Chinese Journal of Geotechnical Engineering，2014，36(1)：176-181.(in Chinese))
[4]	娄扬. 外置双U型静钻根植工法地热能源桩热-力学特性研究[硕士学位论文][D]. 重庆：重庆交通大学，2019.(LOU Yang. Study on thermo-mechanical behaviour of static drill rooted geothermal energy piles with external double U-tubes[M. S. Thesis][D]. Chongqing：Chongqing Jiaotong University，2019.(in Chinese))
[6]	LALOUI L，NUTH M，VULLIET L. Experimental and numerical investigations of the behavior of a heat exchanger pile[J]. International Journal for Numerical and Analytical Methods in Geomechanics，2006，30(8)：763-781.
[28]	费康，戴迪，洪伟. 能量桩单桩工作特性简化分析方法[J]. 岩土力学，2019，40(1)：70-80.(FEI Kang，DAI Di，HONG Wei. A simplified method for working performance analysis of single energy piles[J]. Rock and Soil Mechanics，2019，40(1)：70-80.(in Chinese))
[2]	HAMADA Y，SAITOH H，NAKAMURA M，et al. Field performance of an energy pile system for space heating[J]. Energy and Buildings，2007，39(5)：517-524.
[8]	桂树强，程晓辉. 能源桩换热过程中结构响应原位试验研究[J]. 岩土工程学报，2014，36(6)：1 087-1 094.(GUI Shuqiang，CHENG Xiaohui. In-situ test for structural responses of energy pile to heat exchanging process[J]. Chinese Journal of Geotechnical Engineering，2014，36(6)：1 087-1 094.(in Chinese))
[10]	蒋刚，李仁飞，王昊，等. 摩擦型能源桩热-力耦合全过程承载性能分析[J]. 岩石力学与工程学报，2019，38(12)：2 525-2 534. (JIANG Gang，LI Renfei，WANG Hao，et al. Numerical analysis of bearing capacity of floating energy pile during full process thermal-mechanical coupling[J]. Chinese Journal of Rock Mechanics and Engineering，2019，38(12)：2 525-2 534.(in Chinese))
[16]	方鹏飞，娄扬，赵云，等. 静钻根植工法地热能源桩及其传热管埋设方法：中国，CN108709328B[P]. 2019-12-13.(FANG Pengfei，LOU Yang，ZHAO Yun，et al. A geothermal energy pile with static drill rooted technology and embedding method of heat exchange tube：China，CN108709328B[P]. 2019-12-13.(in Chinese))
[18]	王卫东，凌造，吴江斌，等. 上海地区静钻根植桩成桩效果与质量试验研究[J]. 建筑结构，2019，49(12)：115-119.(Wang Weidong，Ling Zhao，Wu Jiangbin，etc. Experimental study on pile-forming effect and quality of pre-bored precast pile with enlarged base in Shanghai area[J]. Building Structure，2019，49(12)：115-119.(in Chinese))
[5]	江强强，焦玉勇，骆进，等. 能源桩传热与承载特性研究现状及展望[J]. 岩土力学，2019，40(9)：3 351-3 362.(JIANG Qiangqiang，JIAO Yuyong，LUO Jin，et al. Review and prospect on heat transfer and bearing performance of energy piles[J]. Rock and Soil Mechanics，2019，40(9)：3 351-3 362.(in Chinese))
[7]	BOURNE-WEBB P J，AMATYA B，SOGA K，et al. Energy pile test at Lambeth College，London：geotechnical and thermodynamic aspects of pile response to heat cycles[J]. Géotechnique，2009，59(3)：237-248.
[15]	周佳锦，龚晓南，王奎华，等. 静钻根植竹节桩在软土地基中的应用及其承载力计算[J]. 岩石力学与工程学报，2014，33(增2)：4 359-4 366.(ZHOU Jiajin，GONG Xiaonan，WANG Kuihua，et al. Application of static drill rooted precast nodular pile in soft soil foundation and calculation for bearing capacity[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(Supp.2)：4 359-4 366.(in Chinese))
[21]	YAVARI N，TANG A M，PEREIRA J M，et al. Experimental study on the mechanical behaviour of a heat exchanger pile using physical modelling[J]. Acta Geotechnica，2014，9(3)：385-398.
[23]	MURPHY K D，MCCARTNEY J S，HENRY K S. Evaluation of thermo-mechanical and thermal behavior of full-scale energy foundations[J]. Acta Geotechnica，2015，10(2)：179-195.
[24]	SUTMAN M，BRETTMANN T，OLGUN C G. Full-scale in-situ tests on energy piles：Head and base-restraining effects on the structural behaviour of three energy piles[J]. Geomechanics for Energy and the Environment，2019，18：56-68.
[11]	孔纲强，吕志祥，孙智文，等. 黏性土地基中摩擦型能量桩现场热响应试验[J]. 中国公路学报，https：//kns.cnki.net/ kcms/detail/ 61. 1313.U.20200623.1426.002.html.(KONG Gangqiang，LÜ Zhixiang，SUN Zhiwen，et al. Thermal response testing on friction energy piles embedded in clay[J]. China Journal of Highway and Transport. https：//kns.cnki.net/kcms/detail/61.1313.U.20200623. 1426. 002.html (in Chinese))
[17]	中华人民共和国国家标准编写组. GB 50010—2010混凝土结构设计规范[S]. 北京：中国建筑工业出版社，2010.(The National Standards Compilation Group of the People's Republic of China. GB 50010—2010 Code for design of concrete structures[S]. Beijing：China Architecture and Building Press，2010.(in Chinese))
[19]	FAIZAL M，BOUAZZA A，MCCARTNEY J S，et al. Effects of cyclic temperature variations on thermal response of an energy pile under a residential building[J]. Journal of Geotechnical and Geoenvironmental Engineering，2019，145 (10)：04019066.
[25]	路宏伟，蒋刚，王昊，等. 摩擦型能源桩荷载-温度现场联合测试与承载性状分析[J]. 岩土工程学报，2017，39(2)：334-342. (LU Hong-wei，JIANG Gang，WANG Hao，etc. In-situ tests and thermo-mechanical bearing characteristics of friction geothermal energy piles[J]. Chinese Journal of Geotechnical Engineering，2017，39(2)：334-342.(in Chinese))
[20]	FAIZAL M，BOUAZZA A，MCCARTNEY J S，et al. Axial and radial thermal responses of energy pile under six storey residential building[J]. Canadian Geotechnical Journal，2019，56(7)：1 019-1 033.
[22]	VAN WEEL A F. Cast-in-situ piles-Installation methods，soil disturbance and resulting pile behavior[C]// Proceedings of the 1st International Geotech Seminar on Deep Foundations on Bored and Auger Piles. Ghent，Belgium：Van Impe，Balkema，Rotterdam，1988：219-226.
[26]	AMATYA B L，SOGA K，BOURNE-WEBB P J，et al.. Thermo- mechanical behaviour of energy piles[J]. Géotechnique，2012，62(6)：503-519.