超大跨碳纤维增强塑料(CFRP)主缆悬索桥研究与原型设计

Study and Prototype Design of Suspension Bridge with Ultra-long Span and CFRP Main Cables

以非线性数值计算为手段,对比分析缆索系统、加劲梁、桥塔及支承系统等结构系统,研究表明主跨3 500 m CFRP主缆悬索桥具有技术可行性。利用精细有限元结构仿真分析手段,对主跨3 500 m CFRP主缆悬索桥结构体系进行参数敏感性分析,研究结构参数对超大跨径悬索桥静、动力性能影响,结合结构系统数值模型分析研究,确定了主跨3 500 m CFRP主缆悬索桥最优结构体系。建立物理模型,进行CFRP主缆索股的锚固、滑移、弯折等理论分析及静载、疲劳试验研究。研发了可用于实桥的黏结性锚具,锚固效率系数达100%。验证了抗滑移、弯折性能,在鞍座处摩擦系数约0.5,在索夹处达0.331,在鞍座处的弯曲强度超过其抗拉强度的90%,在索夹处几乎不存在弯折问题。以研究成果为依据,进行了主跨3 500 m CFRP主缆悬索桥原型设计。

By means of nonlinear numerical calculation, the structural systems of cable system, stiffening beam, pylon and bearing systems are comparatively analysed. The study shows the technical feasibility of the suspension bridge with 3 500 m main spam and CFRP main cable. By means of fine finite element structural simulation, the parameter sensibility of the suspension bridge structural system with 3 500 m main span and CFRP main cable is analyzed, and influence of structural parameters on the static and dynamic performances of super-long span suspension bridge is discussed. Combining with structural system numerical model analysis, the optimum structural system of the suspension bridge with 3 500 m main span and CFRP main cable is determined. The physical model is set up to conduct theoretical study on anchorage, slip and bending of CFRP main cable strands as well as static load and fatigue test studies. The bond-type anchorage which can be applied to real bridge is developed, the anchorage efficiency coefficient of the anchorage is 100%. The performances of slip resistance and bending are verified, the frictional coefficient between CFRP main cable strand and saddle is about 0. 5, the frictional coefficient between CFRP main cable strand and clamp is up to 0. 331, the bending strength of CFRP wire in the saddle point is over 90% of its tensile strength, and there is almost no bending problem at clamp. The bridge prototype design is performed based on study results of the bridge.