| 引用本文: | 岳著文,李镜培,邵伟.PHC管桩劈裂试验裂缝开展特征[J].哈尔滨工业大学学报,2014,46(10):81.DOI:10.11918/j.issn.0367-6234.2014.10.014 |
| YUE Zhuwen,LI Jingpei,SHAO Wei.Crack development characteristic of PHC pipe pile in splitting test[J].Journal of Harbin Institute of Technology,2014,46(10):81.DOI:10.11918/j.issn.0367-6234.2014.10.014 |
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| 摘要: |
| 为研究预应力高强度混凝土管桩(PHC)受环向压力时裂缝开展特征,针对PHC300型管桩,设计一种裂缝生成劈裂试验方法,该方法能够在钢筋附近生成裂缝,为该型管桩最不利裂缝生成方式,通过对该型号PHC管桩进行劈裂试验,研究其裂缝开展特征.结果表明:PHC管桩受劈裂产生裂缝时,外表面混凝土层裂缝呈现较好的V型特征,裂缝深度随裂缝宽度增大而增大,当裂缝宽度达到0.18 mm时,即形成贯穿裂缝;内表面水泥浆层和砂浆层则易发生整层断裂,裂缝延伸性较好,当裂缝宽度达到0.1 mm时,裂缝贯穿管壁;与实心混凝土相比,PHC管桩空心结构造成混凝土之间有效粘结面积较小,裂缝恢复能力较低,外表面裂缝恢复值随裂缝宽度增大而增大,但裂缝恢复率随裂缝宽度增大而减小,PHC管桩外表面裂缝宽度(COD)恢复率一般在50％以下. |
| 关键词: PHC管桩 劈裂 裂缝 裂缝恢复 |
| DOI：10.11918/j.issn.0367-6234.2014.10.014 |
| 分类号:TU528 |
| 基金项目:国家自然科学基金资助项目(51178341). |
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| Crack development characteristic of PHC pipe pile in splitting test |
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YUE Zhuwen1,2, LI Jingpei1,2, SHAO Wei1,2
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(1. Dept. of Geotechnical Engineering, Tongji University, 200092 Shanghai, China; 2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, 200092 Shanghai, China)
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| Abstract: |
| A special splitting test method has been introduced for PHC300 (prestress high concrete) pipe pile to research the characteristics of crack development due to the toroidal pressure. This crack generation method is considered to be the most negative situation for PHC300 pipe pile since the crack around steels can often be observed. The results show that crack depth increases with crack width in outer surface of PHC. The crack runs through the wall thickness of PHC as the measured crack width reach to 0.18 mm in outer concrete surface and 0.1 mm in inner surface, respectively. This is probably due to the crack extensibility, i.e., inner surface has a better extensibility than outer surface because cement paste layer and mortar layer tend to integral fracture in inner surface. Compared with a solid concrete structure, the crack in PHC is seemly difficult to recovery due to a relatively small bonding area in outer concrete surface contributed by the hollow structure. Crack recovery values increase with the increase of crack widths in outer surface, while crack recovery rates is opposite. The recovery rates of crack open displacement (COD) in outer surface are generally below 50％. |
| Key words: PHC pipe pile splitting test crack crack recovery |
