摘要
合理考虑两跨连续梁在加载过程中受力模式的变化和无粘结筋的应力增量对支座控制截面正截面抗弯承载力的贡献,选择合理的结构“失效”标志,就可应用相关设计规程所给刚度计算公式按等刚度法计算结构的变形,求得无粘结筋在外载下的伸长,从而确定无粘结筋极限应力。据此,通过计算机模拟分析,探讨了在不同荷载作用下两跨适筋连续梁中无粘结筋极限应力增量随普通钢筋配筋指标βs和预应力筋配筋指标βp的变化规律,建立了与现有试验结果相吻合的两跨连续梁中无粘结筋极限应力的计算公式。
The method for calculating stresses in unbonded prestressing tendons is proposed as follows：calculating the deflection of two-span continuous beam subjected to external load by equal stiffness method which is accord with stiffness formulae of design criteria;calculating the elongation of unbonded tendons;calculating stresses in unbonded prestressing tendons due to elongation. This method is put forward on the basis that the change of mechanical modes of two-span continuous beam is rationally taken into account in the process of loading ,and the contribution of the stress increment in tendons in this change procedure to bearing capacity of support, as well as the failure criterion of the structure is reasonably selected. The influence law of the change of prestressing steel reinforcement index βp and the non-prestressed tensile steel reinforcement index βs is studied to ultimate stresses in unbonded prestressing tendons of two-span beam of mediate steel with different types of load. Calculation formulae of stress in unbonded tendons at ultimate in continuous two-span prestressed concrete beam are presented, which are accorded with experimental results.
出处
《建筑结构》
CSCD
北大核心
2005年第7期67-71,共5页
Building Structure
基金
国家自然科学基金项目(50178026)。
