[1]魏明畅,孟永东,朱 超,等.回填土钻孔灌注桩-承台混凝土水化作用 效应现场试验[J].防灾减灾工程学报,2019,39(04):622-627.[doi:10.13409/j.cnki.jdpme.2019.04.012]
 WEI Mingchang,MENG Yongdong,ZHU Chao,et al.Field Test on Concrete Hydration Effect of Bored Pile in Backfill Soil[J].Journal of Disaster Prevention and Mitigation Engineering,2019,39(04):622-627.[doi:10.13409/j.cnki.jdpme.2019.04.012]
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回填土钻孔灌注桩-承台混凝土水化作用 效应现场试验()
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防灾减灾工程学报[ISSN:1672-2132/CN:32-1695/P]

卷:
39卷
期数:
2019年04期
页码:
622-627
栏目:
论文
出版日期:
2019-08-31

文章信息/Info

Title:
Field Test on Concrete Hydration Effect of Bored Pile in Backfill Soil
文章编号:
1672-2132(2019)04-0622-06
作者:
魏明畅1 孟永东1 朱 超1 方金城2 孔纲强12
(1.三峡大学水利与环境学院, 湖北 宜昌 443002; 2.河海大学土木与交通学院, 江苏 南京 210098)
Author(s):
WEI Mingchang1 MENG Yongdong1 ZHU Chao1 FANG Jincheng2 KONG Gangqiang12
(1.College of Water Conservancyand Environment, Three Gorges University, Yichang 443002, China; 2.College ofCivil and Transportation, Hohai University, Nanjing 210098, China)
关键词:
回填土 钻孔灌注桩 水化热 现场试验
Keywords:
backfill soil bored pile hydration heat fieldtest
分类号:
TU435
DOI:
10.13409/j.cnki.jdpme.2019.04.012
文献标志码:
A
摘要:
混凝土早期水化作用释放大量热量,会引起桩身温度和桩身应力变化,从而影响桩基承载性能。通过开展现场试验,研究回填土地基中钻孔灌注桩-承台混凝土水化热对桩身及桩基周围土体的影响,实测并分析了桩身及桩基周围土体温度随时间、深度的变化规律和桩基应力随时间的变化规律。研究结果表明,试桩混凝土浇筑完成后,0.7 d时桩体不同深度处的温度均达到最大值,21.4d时其温度基本稳定; 桩体温度随时间变化规律可分为快速上升、快速下降、缓慢降低和基本稳定4个阶段。承台混凝土水化热效应仅对桩基周围浅层土体温度有一定影响,当深度大于3 m时,其对土体的温度作用效应基本可以忽略。桩基约束应力变化表现为先迅速增长再缓慢下降最终趋于稳定,最大约束应力值与混凝土轴心抗拉强度十分接近。
Abstract:
The early hydration of concrete will release a lot of heat, which will cause the change of temperature and stress of pile body, thus affecting the bearing capacity of pile-cap. Through field tests, the influence of hydration heat of bored pile-cap concrete on pile body and soil around pile foundation is studied. The variation of temperature of the pile foundation and the soil around pile along depth and with time, and the stress history of pile foundation are measured and analyzed. The results show that the temperature at all depths of the pile reaches its maximum value at day 0.7 after the completion of concrete pouring. At day 21.4, the temperature of the pile is basically stable. The law of temperature variation with time can be divided into four stages: rapid rise, rapid decline, gentle decrease and basic stability. The hydration heat effect of cap concrete has only a certain effect on the temperature of shallow soil around pile foundation. When the depth is more than 3 m, the effect of hydration heat on the temperature of soil can be neglected. The confinement stress of pile foundation first increases rapidly, then decreases slowly and finally tends to be stable. The maximum confinement stress value is very close to the axial tensile strength of concrete.

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备注/Memo

备注/Memo:
收稿日期:2019-03-13; 修回日期:2019-04-09 基金项目:国家重点研发计划项目(2017YFC1501100)、国家自然科学基金项目(51679129)资助 作者简介:魏明畅(1996-),女,硕士研究生。主要从事能源地下结构方面的研究。Email:1113083231@qq.com 通讯作者:孟永东(1976-),男,教授,博士。主要从事水工结构工程及岩土工程方面的研究。 Email:meng@ctgu.edu.cn
更新日期/Last Update: 2019-09-15