围套加固石砌体小偏心受压构件正截面承载力的计算

Bearing Capacity Calculation of Normal Section of Stone Masonry Members Enclosed by Reinforced Concrete

针对围套加固石砌体小偏心受压构件加固后的正截面承载力计算问题,通过模型实验研究和理论推导分析,得出综合考虑加固结构不同组成材料的力学参数、二次受力特征及截面应力-应变非线性关系多种影响因素的计算方法,并通过对试件的计算,验证了此方法的可靠性。通过计算分析,本文得出试件初始应力水平对组合加固构件正截面承载力的影响曲线。曲线表明当初始应力水平指标β0.7时,正截面承载力有所增长,但增长幅度不超过5%,所以可以按照一次性受力进行承载力的计算;而当β>0.7时,应力水平对承载力的影响不可忽略。随着应力水平的增长,承载力不断下降,所以在实际工程中对初应力水平较高的加固构件应进行卸载。

A calculation method considering manifold influence factors including the different mechanical material properties,the stress state existence in stone masonry and the stress-strain nonlinear relationship is given in this paper based on model experiment and theoretical analysis aiming at the bearing capacity of normal section of stone masonry members enclosed by reinforced concrete.The reliability was confirmed by analyzing the experiment.An influence curve describing the influence of existed stress level on the bearing capacity of normal section of the members enclosed by reinforced concrete was obtained.The curve shows that when the existed stress level β≤0.7,the bearing capacity of normal cross-section increases,but the growth rate less than 5%,therefore the bearing capacity of normal section is analyzed according the one-off loading members.When β0.7,the influence cannot be ignored,the bearing capacity decreases with the existed stress level increasing.Therefore the unloading should be done to the member strengthened with relatively high stress level in engineering practice.