钢主缆与CFRP主缆悬索桥力学性能及极限跨径研究

运用解析法研究了在现有材料强度的基础上,钢主缆和CFRP主缆悬索桥的极限跨径。结果表明,跨径超过4 500 m后,钢主缆悬索桥的主缆直径将急剧增大,恒载所占比重超过全桥总荷载的95%,不宜采用;而CFRP主缆悬索桥在跨径超过5 000 m后,主缆面积仍能保持平稳增长,且远小于相同跨径下钢主缆所需面积,可行性高。此外,分别对主跨为1 500、2 000、3 000、4 000和5000m的钢主缆和CFRP主缆单跨悬索桥进行试设计,并对主缆、锚锭及桥塔受力、活载作用下的加劲梁挠度等力学性能进行了对比分析。得出:2 000 m以下的悬索桥钢主缆具有优势,而3 000 m以上的悬索桥采用CFRP主缆是可取的。

The study on mechanical properties and ultimate span of suspension bridge with steel cable and CFRP cable

Based on the strength of existing material, the research studies the ultimate span of steel cable and CFRP cable suspension bridge using analytic method. The result shows that the diameter of steel cable will increase sharply and its self-weight will account for 95% of total loads when the span is over 4 500m, which is no more suitable to adopt; however, the area of CFRP cable can still grow steadily when the span is over 5 000 m and its value is far less than the one of steel cable in same span, which is rather feasible. In addition, steel cable and CFRP cable suspension bridge with main span of 1 500, 2 000, 3 000, 4 000, 5 000m are tried to be designed and comparative analysis of their mechanical properties are made in the study. In conclusion, it is suitable to use steel cable when the span is less than 2 000 m while CFRP cable is more feasible when it is over 3 000m.