拱桥吊杆的弯矩作用是导致其锚固端开裂的主要因素之一，为了准确模拟锚固端的杆端弯矩，将吊杆两端的减振器简化为支撑弹簧，建立支撑弹簧模型，推导吊杆杆端弯矩的解析解，给出支撑弹簧刚度和吊杆截面抗弯刚度的确定方法，并以138φs5平行钢丝束吊杆为例，编制MATLAB程序分析支撑弹簧刚度、吊杆截面抗弯刚度和吊杆长度等参数对杆端弯矩的影响，并对吊杆支撑弹簧模型和铰接模型、固结模型进行对比。结果表明：吊杆杆端弯矩随支撑弹簧刚度的增大而逐渐增大并趋于平缓，杆端弯矩随吊杆抗弯刚度的增大而增大；伸入拱肋和桥面系横梁的吊杆长度对杆端弯矩有一定影响；当吊杆长度小于10m时，随着长度增加，杆端弯矩迅速减小；当吊杆长度大于10m时，吊杆长度对杆端弯矩值影响很小，可以忽略不计。%T he bending moment action of the hangers of arch bridge is one of the major factors causing the cracks in the hangers at their the anchorage ends .To accurately simulate the bar end bending moment of the hangers at the anchorage ends ,the dampers at the tw o ends of the hangers were simplified as the support springs ,the model for the support springs was established ,the ana‐lytical solutions for the bar end bending moment of the hangers were derived and the determination methods for the support spring stiffness and the sectional bending stiffness of the hangers were given .By way of example of the 138φs 5 parallel steel wire strand hangers ,the program MATLAB was complied ,the influences of the parameters like the support spring stiffness and the sectional bending stiffness and length of the hangers on the bar end bending moment were analyzed and the support spring model was compared to the hinge model and fixity model .The results demonstrate that with the increase of the support spring stiffness ,the bar end bending moment of the hangers gradually increases and tends to be gentle and with the increase of the bending stiffness of the hangers ,the bar end bending moment also increases .The length of the hangers extending into the arch rib and cross beams of the floor system has certain influences on the bar end bending moment . When the length of the hangers is shorter than 10 m ,the bar end bending moment rapidly decrea‐ses with the increase of the length of the hangers and when the length of the hangers is longer than 10 m ,the influences of the length of the hangers on the bar end bending moment are very little and can be ig no red .
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