长期荷载作用下SFRC梁承载能力极限状态可靠性分析
为分析长期荷载作用下SFRC梁承载能力极限状态可靠性的时变规律,基于持荷10年的SFRC梁抗弯试验结果,建立了SFRC梁承载能力极限状态时变可靠性分析模型.对于Ⅰ系列梁(持荷水平不变、钢纤维掺量改变)和Ⅱ系列梁(持荷水平改变、钢纤维掺量不变),将等效抗力法和一次二阶矩法相结合,求得其时变可靠指标,并预测了100年长期荷载作用下可靠性的时变规律.结果表明:对于Ⅰ系列梁,钢纤维体积分数为0.5%是最佳掺量;对于Ⅱ系列梁,外荷载越小,可靠指标越大,抗弯承载力越大,外加荷载越接近,可靠指标越接近;在服役期内SFRC梁可靠指标先上升后下降,当钢筋开始锈蚀,可靠指标曲线出现拐点,导致梁正截面抗弯承载力下降...
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Published in | 东北大学学报(自然科学版) Vol. 38; no. 7; pp. 1055 - 1059 |
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Main Author | |
Format | Journal Article |
Language | Chinese |
Published |
新加坡国立大学, 新加坡 119260
2017
东北大学 资源与土木工程学院,辽宁 沈阳,110819%东北大学 资源与土木工程学院, 辽宁 沈阳 110819 |
Subjects | |
Online Access | Get full text |
ISSN | 1005-3026 |
DOI | 10.12068/j.issn.1005-3026.2017.07.029 |
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Summary: | 为分析长期荷载作用下SFRC梁承载能力极限状态可靠性的时变规律,基于持荷10年的SFRC梁抗弯试验结果,建立了SFRC梁承载能力极限状态时变可靠性分析模型.对于Ⅰ系列梁(持荷水平不变、钢纤维掺量改变)和Ⅱ系列梁(持荷水平改变、钢纤维掺量不变),将等效抗力法和一次二阶矩法相结合,求得其时变可靠指标,并预测了100年长期荷载作用下可靠性的时变规律.结果表明:对于Ⅰ系列梁,钢纤维体积分数为0.5%是最佳掺量;对于Ⅱ系列梁,外荷载越小,可靠指标越大,抗弯承载力越大,外加荷载越接近,可靠指标越接近;在服役期内SFRC梁可靠指标先上升后下降,当钢筋开始锈蚀,可靠指标曲线出现拐点,导致梁正截面抗弯承载力下降明显. |
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Bibliography: | 21-1344/T SFRC beam; long-term load; load-carrying capacity; time- dependent; reliability LI Yi1,DONG Jin-xia1,TAN Kiang Hwee1,2(1. School of Resources & Civil Engineering,Northeastern University,Shenyang 110819,China; 2. National University of Singapore,Singapore 119260, Singapore) Time-dependent reliability model for the ultimate load-carrying capacity of steel fiber reinforced concrete (SFRC) beams subjected to long-term load is established based on the results obtained from the beams under sustained load ten years. Two series of tested beams are considered : Series I with constantly applied load but varying steel fiber content, and Series II with the same steel fiber content but subjected to different applied loads. The time-dependent reliability indexes are determined and the reliability pattern for 100 years of long-term load is forecasted using the equivalent resistance method and the first- order- second-moment method. The results show that the optimum content of steel fibers is 0. 5 % in Series I beams; |
ISSN: | 1005-3026 |
DOI: | 10.12068/j.issn.1005-3026.2017.07.029 |