Due to the unique modeling of butterfly-shaped arch bridge,the nonlinear mechanical behavior is difficult to master compared with ordinary arch bridges,and the traditional design method which is not fully considered in nonlinear influence is not applicable.On the basis of self-compiled program, the nonlinear property and its influencing factors were comprehensively analyzed according to butterfly -shaped arch bridge.The results showed that the nonlinear coefficients of main cable forces are inversely proportional to the values of cable force under uniform load.The main cable sag has most influence on nonlinear cable forces.The beam-column effect of arch-rib elements accounts for small percentage in total effect for the main cable forces.When the dense cable system is adopted,the stay cable forces are not reliable if the cable sag is not considered.The nonlinear factors have less influence on cable forces when the eccentric load is close to cable plane.When the main cables are tilted,the own nonlinear effect is decreased,however,the nonlinear effect of stay cables and subsidiary cables is increased.
