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(1 四川省建筑設(shè)計研究院有限公司, 成都 610095; 2 四川省建筑設(shè)計研究院有限公司復(fù)雜結(jié)構(gòu)設(shè)計研究中心, 成都 610095; 3 成都惟尚建筑設(shè)計有限公司, 成都 610096)
摘要: 為研究足尺毛竹梁的長期蠕變性能,分析了已有的試驗(yàn)數(shù)據(jù),進(jìn)一步探究毛竹梁在長期荷載作用下的蠕變規(guī)律. 從微觀層次分析了竹材蠕變性能隨環(huán)境濕度、溫度變化而改變的機(jī)理;以強(qiáng)度儲備、蠕變速率以及相對撓度作為控制指標(biāo),評估了毛竹梁的蠕變性能;對毛竹梁蠕變模型開展了適用性研究,并基于蠕變模型的撓度預(yù)測給出了毛竹梁的建議應(yīng)力比. 結(jié)果表明:環(huán)境中濕度和溫度的變化會引起竹材的物理性質(zhì)發(fā)生變化,從而改變竹材的蠕變性能;應(yīng)力比較小的毛竹梁蠕變性能總體上符合工程使用要求;將 Burger 模型中表征黏性變形的線性函數(shù)改進(jìn)為冪函數(shù),改進(jìn)的 Burger 模型結(jié)合了 Burger 模型和冪律模型的特點(diǎn),能更好地模擬毛竹梁的蠕變性能. 最后,基于蠕變模型的長期變形預(yù)測值,建議了毛竹梁應(yīng)力比不應(yīng)大于 0. 50,以防止原竹建筑在 50 年的設(shè)計基準(zhǔn)期內(nèi)產(chǎn)生過大的蠕變變形.
關(guān)鍵詞: 毛竹梁; 長期蠕變; 應(yīng)力比; 性能評估; 改進(jìn)的 Burger 模型; 撓度預(yù)測
中圖分類號:TU366. 1 文獻(xiàn)標(biāo)志碼:A 文章編號: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
∗四川省科技計劃資助(2023YFS0393),四川省住房城鄉(xiāng)建設(shè)領(lǐng)域科技創(chuàng)新課題 ( SCJSKJ2022-33),四川省建筑設(shè)計研究院有限公司科研項(xiàng)目(KYYN202221).
第一作者:鐘紫勤,碩士,助理工程師,主要從事竹結(jié)構(gòu)設(shè)計與研究,Email:2283222749@ qq. com.
[引用本文] 鐘紫勤,趙仕興,陳可,等. 足尺毛竹梁長期蠕變性能研究[ J]. 建筑結(jié)構(gòu),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.
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