马鞍山长江公路大桥左汊主桥基础设计

摘要

The left main bridge of Maanshan Changjiang River Highway Bridge is a three-tower two -span suspension bridge with span arrangement of (360 + 2 × 1 080 + 360) m .The in-terme-diate tower columns stand in the region where the water is deep and the scour depth is great ,hence ,the bored piles that are 3 .0 m in diameter are chosen for the foundation through scheme comparison and selection .The foundation of the bored piles is characterized by its rational load distribution ,relatively small number of piles and short over-water construction time .The piers of the south and north towers stand respectively on the two shores of the main navigation channel and located in shallow water or land areas ,by scheme comparison and selection , the bored piles of 2 .5 m in diameter are chosen for the foundation .This scheme is economic ,simple and applicable .Through the comparison of the caisson and diaphragms ,the foundations of the south and north anchors adopt the caisson scheme due to its mature construction technique and sound economic performance .The design verification showed that the strength ,rigidity and sta-bility of the tower foundations and the caissons of the anchors all met the requirements .%马鞍山长江公路大桥左汊主桥为（360＋2×1080＋360） m 三塔两跨悬索桥，中塔墩位处水深、冲刷深度大，通过比较选择了φ3．0 m 钻孔桩方案，该方案大直径钻孔桩受力较合理，桩数相对较少，水上施工时间也较短；南、北边塔墩位于主槽两侧边滩，处于浅水或无水区域，通过比较选择了φ2．5 m 钻孔桩方案，该方案较为经济、简单易行；通过比较沉井和地下连续墙方案，南、北锚碇基础均选择了施工工艺成熟、经济性较好的沉井方案。经设计验算，各塔墩的桩基础和锚碇的沉井基础的强度、刚度和稳定性均满足要求。