大卸载条件下受拉区加固梁的抗弯设计法

本文以应变平截面假定为基础，对非卸载条件下受拉区加固梁截面的钢筋应变发展及抗弯承载力的发展进行分析研究。研究表明，初弯矩比越大，承载能力极限状态下增补钢筋应变发展越低；增补钢筋用量越大，初配钢筋应变发展越低。当初配钢筋配筋量较小时，即使初弯矩比较大，只要增补钢筋配筋量适当，可以保证初配钢筋及增补钢筋均受拉屈服，并使截面抗弯承载力得到显著提高。

Design Method of Moment-strengthening on Tension Side When Load Un removed

Based on the linear strain distribution assumption, strain development of tensile bars and ultimate moment capacity of strengthening section, which strengthened on tension side with service load un removed, is investigated. It is showed that the higher the service load bending moment to original moment capacity ratio M 1k /M u1 is, the smaller the tensile strain of strengthening re barsis, and the more the amount of strengthening re barsis, the smaller the tensile strain of original re barsis. It also showed that,When original re bar area is relatively small and strengthening re bar area is adequate, both original and strengthening re bars may get yielded and a great increment in section moment capacity is achieved, even though the ration M 1k M u1 has a relatively high value.