黄河三峡大桥桥型方案比选

Bridge Type Selection for Yellow River Three Gorges Bridge

黄河三峡大桥为河南省济源至新安高速公路的控制性工程。综合考虑地形、地质和环保等方面,提出单跨跨径510 m的双塔悬索桥、主跨510 m独塔回转缆悬索桥(桥塔置于南岸、主缆在北岸锚碇处通过转索鞍回转锚固)及计算跨径435 m中承式钢管混凝土拱桥3个方案,并对受力性能、建设规模、环境影响、施工难度等进行比较。结果表明:3个方案静、动力性能均能满足规范要求,独塔回转缆悬索桥经济性不占优势,但施工难度最低、工期可控,且该方案在北岸仅设置覆表式重力锚,取消了桥塔,很好地解决了地质遗迹保护区环保要求高、构造物设置受限的问题,与隧道衔接性好,作为推荐方案。

The Yellow River Three Gorges Bridge is a control project of the Jiyuan-Xin′an Expressway in Henan Province.To accommodate the specific topographic and geological conditions at the bridge site as well as the environmental protection requirements,three bridge types were proposed,including the two-tower suspension bridge with a main span of 510 m and with hanger cables arranged only in main span,one-tower suspension bridge with a main span of 510 m(where the tower is located at the south bank,the main cables are anchored to the north-bank anchorage in a looping manner via a deviation saddle),and a half-through concrete-filled steel tubular arch bridge with a calculated main span length of 435 m.The three options were compared from perspectives of load bearing performance,construction scope,environmental impact and construction challenges.It is shown that all the three options meet the static and dynamic property requirements in the code.The one-tower suspension bridge with loop-anchored main cables exhibits poor economy,but wins over the other two options in terms of easier construction and controllable construction schedule,in addition,the one tower solution requires only a shallow gravity anchorage on Jiyuan bank,making a good reconciliation with the critical environmental protection requirements and the limited construction space at the bridge site.Moreover,the one-tower suspension bridge solution also creates smooth connection to the access tunnel,thus being the final recommended solution.