摘要：研究目的:我国设计规范因缺少高强钢筋疲劳设计参数，给高强钢筋在铁路工程中的推广应用带来 困难。为贯彻落实国家产业政策，充分发挥高强钢筋技术经济性能以及为标准修订提供技术支撑，开展铁路 工程应用高强钢筋的试验研究。针对两种生产工艺（微合金化、细晶粒），两个强度级别(400 MPa、500 MPa)， 四种直径（16 mm、20 mm、25 mm、32 mm)的高强钢筋进行研究。系统进行高强钢筋母材及连接接头的疲劳性 能试验，疲劳试验的截止循环次数为107次。 研究结论：(1)采用动态标定措施后，母材、接头的对比试验均表明高频疲劳试验机与低频疲劳试验机试 验结果无明显差异，高频疲劳试验机可用于高强钢筋的疲劳试验；（2)摸索出适用于不同强度级别高强钢筋 母材和接头的夹持端处理方法，解决了钢筋疲劳试件在夹持端易于断裂的技术难题，避免了钢筋疲劳试件的 定制，实现了钢筋试件的随机取样；（3)通过对大量试验数据的统计分析，提出了高强钢筋母材及闪光对焊、 电弧焊、直螺纹三种连接接头的应力循环次数达107次的P 斤曲线和疲劳抗力方程，填补了国内空白，为高强钢筋在我国的推广应用提供了依据；（4)根据107次高疲劳寿命区的特点，采用双对数双折线方法进行 试验数据的分析处理，并综合考虑了置信度、保证率等因素，使P-S-W曲线适用于不同样本条件，较好地反 映了高强钢筋疲劳试件的统计特征，为高强钢筋疲劳抗力试验成果的总结提供了理论依据；（5)提出的铁路工程混凝土结构高强钢筋设计规定，其高强钢筋疲劳承载能力计算方法综合考虑了应力比、直径、强度等级、 疲劳损伤、疲劳构造细节类型的影响，且形式上为与国际主流规范接轨的应力幅计算公式，便于设计者使用，（6）该研究成果可广泛应用于我国混凝土结构设计中。

Abstract ：Research purposes： Current Chinese design specifications lack of fatigue design parameters of high - strengtli bars， which is not conducive to popularization and application of high - strengtli bars in the railway engineering. To implement the national industrial policy，realize high - strength bars technical and economic performance and provide technical support for standards， railway engineering application of high - strengthi bars was studied. Two production processes( micro - alloyed and fine - grained)，two levels of intensity(400 MPa and 500 MPa)，four diameters(16 mm， 20 mm，25 mm and 32 mm) high - strength bars were studied. Fatigue performance test of high - strength bars base material and connecting joints was carried out，as the number of fatigue test for cycles 10= times. Research conclusions ：( 1) After the dynamic calibration measures，comparative tests of base material and connecting joints showthat there was no significant difference between the high - frequency fatigue testing machine test results and the low - frequency fatigue testing machine test results，high - frequency fatigue testing machine could be used to test high - strength bars. (2) The gripping end processing method of high - strength bars base material and connecting joints was mastered which solved the technical problems of high - strength bars fatigue specimen grij) end easily broken ；avoided custom high - strength bars fatigue specimens ； achieved a random sample of high - strength bars fatigue specimens. (3 ) By a large number of test data statistical analysis ； research presented p - " - ： curve equation and fatigue resistance of high strength bars base material and flash butt welding，arc welding，straight thread connecting joints ； stress cycles was taken as 10 times. It provided the basis for the use of the high - strength bars. (4) According to the characteristics of 10 high fatigue life region，double logarithmic bilinear methods for data analysis，and considering the confidence，guaranteed rate and other factors curves for diferent sample conditions， statistics reflect the characteristics of high - strengtli bars fatigue specimens，to sum up the high - strengtli bars fatigue resistance test results provide a theoretical basis. (5 ) Study proposed railway projects of high - strengtli bars concrete structure design requirements. High - strengthi bars fatigue bearing capacity calculation methiod take into account thie effect of stress ratio， diameter， strength level，fatigue damage，fatigue type of construction details. Stress amplitude was calculated in the form of specifications consistent wit!i the international mainstream. (6 ) The research results will be widely used in the design of concrete structures.