基于数据库的连续深受弯构件受剪承载力研究

Research on shear strength of reinforced concrete continuous deep flexural members based on database

为评估中、美规范计算方法对连续深受弯构件受剪承载力预测的安全性,通过搜集和筛选国内外文献中的试验研究成果,建立了钢筋混凝土连续深受弯构件受剪试验数据库。对美国规范ACI 318-2011采用的拉压杆模型(STM)计算方法以及GB 50010—2010《混凝土结构设计规范》中深受弯构件受剪承载力计算公式进行了分析。在此基础上,利用所建立的数据库对中、美两国规范中的计算方法进行评估。结果表明:两规范的计算结果均高估了连续深受弯构件的受剪承载力;对于中国规范中深受弯构件的受剪承载力计算公式,建议将其剪跨比λ的上限值取3.00,下限值取0.25,可以使其偏安全地用于连续深受弯构件计算;对于美国规范中所采用的STM,则可通过调整压杆混凝土有效系数,提高其安全度。

For evaluating the safety of code models for the shear strength of continuous deep flexural members,a shear tests database is built in this paper by collecting and filtering the test results in literatures and research reports. The strut-and-tie model（ STM） adopted by the American code ACI 318-11 and the shear strength equation for deep flexural members in the Chinese code GB 50010—2010 are analyzed and evaluated based on the database. The results indicate that both of the codes overestimate the shear strength of continuous deep flexural members. For the Chinese code,by setting the upper and lower limits of the shear span-to-depth ratio λ to 3. 00 and 0. 25 respectively,its equation can safely estimate the shear strength of continuous deep flexural members; for STM in the American code,its safety is improved by modifying the effective coefficient of concrete in strut.