SEISMIC RESPONSE OF THREE-TOWER SELF-ANCHORED SUSPENSION BRIDGE WITH SLIDING SADDLE

Aimed to improve safety factor against cable sliding of three-tower self-anchored suspension bridge (TSSB) under live load, the sliding saddle system was presented in preiminary design. Considering collision between saddle and baffleplate, this paper compares the seismic response of TSSB with sliding saddle to TSSB with fixed saddle by the Finite Element Method. The analysis result shows that the use of sliding saddle can raise safety factor against cable sliding under seismic excitation, but along with increasing of seismic response of main towers, and mechanics characteristics of saddle becoming more complex. Besides, this paper discusses the influence rule of impaction stiffness and initial gap on seismic response. Parametric studies shows that smaller impaction stiffness of sliding saddle can reduce the seismic response of saddle and the critical initial gap value to avoid the collision of sliding saddle is suggested.