(1 四川省建筑设计研究院有限公司, 成都 610095; 2 四川省建筑设计研究院有限公司复杂结构设计研究中心, 成都 610095; 3 成都惟尚建筑设计有限公司, 成都 610096)

摘要: 为研究足尺毛竹梁的长期蠕变性能,分析了已有的试验数据,进一步探究毛竹梁在长期荷载作用下的蠕变规律. 从微观层次分析了竹材蠕变性能随环境湿度、温度变化而改变的机理;以强度储备、蠕变速率以及相对挠度作为控制指标,评估了毛竹梁的蠕变性能;对毛竹梁蠕变模型开展了适用性研究,并基于蠕变模型的挠度预测给出了毛竹梁的建议应力比. 结果表明:环境中湿度和温度的变化会引起竹材的物理性质发生变化,从而改变竹材的蠕变性能;应力比较小的毛竹梁蠕变性能总体上符合工程使用要求;将 Burger 模型中表征黏性变形的线性函数改进为幂函数,改进的 Burger 模型结合了 Burger 模型和幂律模型的特点,能更好地模拟毛竹梁的蠕变性能. 最后,基于蠕变模型的长期变形预测值,建议了毛竹梁应力比不应大于 0. 50,以防止原竹建筑在 50 年的设计基准期内产生过大的蠕变变形.

关键词: 毛竹梁; 长期蠕变; 应力比; 性能评估; 改进的 Burger 模型; 挠度预测

中图分类号:TU366. 1 文献标志码:A 文章编号:1002-848X(2023)07-0118-07

DOI:10. 19701 / j. jzjg. SADI2322

Study on long-term creep performance of full-culm Moso bamboo beam

ZHONG Ziqin1,2, ZHAO Shixing1,2, CHEN Ke3, ZHOU Qiaoling1,2

(1 Sichuan Provincial Architectural Design and Research Institute Co. , Ltd. , Chengdu 610095, China; 2 ComplexStructure Design and Research Center, Sichuan Provincial Architectural Design and ResearchInstitute Co. , Ltd. , Chengdu 610095, China; 3 Sunway International Co. , Ltd. , Chengdu 610096, China)

Abstract: In order to study the long-term creep performance of full-culm Moso bamboo beams, the existing test data wereanalyzed, and the creep law of full-culm Moso bamboo beam under long-term load was further explored. The mechanismthat the creep performance of bamboo changes with the environmental humidity and temperature was analyzed from themicroscopic level. The creep performance of Moso bamboo beam was evaluated by adequate strength, creep rate andfractional deflection. The applicability of creep models of Moso bamboo beam was studied, and the recommended stressratio of Moso bamboo beam was given based on the deflection prediction of creep models. The results show that the changesof humidity and temperature in the environment would cause changes in the physical properties of bamboo, thus changingthe creep performance of bamboo. The creep performance of Moso bamboo beam with small stress ratio generally meet theengineering requirements. The viscosity deformation in Burger model is modified as a linear function of time to a powerfunction, and the modified Burger model combines the characteristics of Burger model and power function model, which canbetter simulate the creep performance of Moso bamboo beam. Finally, based on the long-term deformation prediction of thecreep model, it is suggested that the stress ratio of Moso bamboo beam should not be greater than 0. 50 to prevent excessivecreep deformation of the original bamboo building in the 50 year design reference period.

Keywords: Moso bamboo beam; long-term creep; stress ratio; performance evaluation; modified Burger model;deflection prediction

∗四川省科技计划资助(2023YFS0393),四川省住房城乡建设领域科技创新课题 ( SCJSKJ2022-33),四川省建筑设计研究院有限公司科研项目(KYYN202221).

第一作者:钟紫勤,硕士,助理工程师,主要从事竹结构设计与研究,Email:2283222749@ qq. com.

[引用本文] 钟紫勤,赵仕兴,陈可,等. 足尺毛竹梁长期蠕变性能研究[ J]. 建筑结构,2023,53( 7):118-124.ZHONG Ziqin,ZHAO Shixing,CHEN Ke,et al. Study on long-term creep performance of full-culm Moso bamboo beam[J].Building Structure,2023,53(7):118-124.