二次受力对粘贴钢板加固梁承载力的影响

Effects of re-force on steel-strengthened reinforced beam's capacity

考虑到现行《公路桥梁加固设计规范》中粘贴钢板加固钢筋混凝土梁承载力计算公式的不足,应用弹性力学理论通过对正截面受弯承载力等计算公式进行理论推导,分析了二次受力对加固效果的影响。研究结果表明:考虑二次受力影响,钢筋混凝土梁粘贴钢板加固后极限承载力理论计算公式与不考虑二次受力有一定差异;在适筋梁破坏下,随第一次受力情况,二次受力对界限受压区高度有不同的影响;依据受拉区所需最大粘贴钢板量计算公式,可以避免加固后梁出现超筋脆性破坏。

There are some shortcomings existing in the bearing capacity formula of bonded steel reinforced concrete structure in the Specifications for Strengthening Design of Highway Bridges. The flexural capacity of the theoretical formula is derived and the reinforcement effect on the secondary load is analyzed by the application of theory of elasticity. The results show that; there are some differences in theoretical formula of ultimate bearing capacity in steel-strengthened reinforced beam between considering the effect of secondary load and not considering; under damage of balanced-reinforced beam, the balanced depth of compression zone have been differently affected by the secondary load compared, with the first force; the brittle failure of over-reinforced beam can be avoided in steel-strengthened reinforced beam by theoretical formula. 3 figs, 16 refs.