长期荷载作用下SFRC梁承载能力极限状态可靠性分析

发布时间：2019-06-19 22:44

【摘要】：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.
[Abstract]:In order to analyze the time-varying law of ultimate state reliability of SFRC beam under long-term load, based on the bending test results of SFRC beam with 10 years of load, the time-varying reliability analysis model of load-bearing capacity of SFRC beam is established. For the I series beams (constant load level, steel fiber content change) and II series beams (the load holding level changes, the steel fiber content does not change), the equivalent resistance method and the first order second moment method are combined to obtain the time-varying reliability index, and the time-varying law of reliability under 100 years of long-term load is predicted. The results show that 0.5% of steel fiber volume fraction is the best content for series I beams, the smaller the external load is, the greater the reliability index is, the greater the bending capacity is, the closer the applied load is, the closer the reliability index is. During the service period, the reliability index of SFRC beams increases at first and then decreases, and when the steel bar begins to rust, the curve of reliability index appears inflection point, which leads to the decrease of bending bearing capacity of the normal section of the beam.
【作者单位】：东北大学资源与土木工程学院;新加坡国立大学;
【基金】：教育部新世纪优秀人才支持计划项目(NCET-12-0107) 中央高校基本科研业务费专项资金资助项目(N130401009) 辽宁省高等学校优秀人才支持计划项目(LR2015024)
【分类号】：TU37

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