新建安九铁路鳊鱼洲长江大桥总体设计

新建安九铁路鳊鱼洲长江大桥采用两线350 km/h高铁及两线200 km/h客货共线标准建设。南汊航道桥采用主跨672 m双塔钢箱混合梁交叉索斜拉桥,北汊航道桥采用主跨2×140 m独塔竖琴式预应力混凝土梁斜拉桥,鳊鱼洲及北汊非通航孔区采用48 m简支梁桥,跨北岸大堤采用主跨100 m变高连续梁桥,南、北岸引桥除连续梁外均采用32 m、24 m铁路标准梁,基础均采用桩基础。其中南、北汊航道桥采用整幅修建,其余采用分幅修建。桥址区基岩为灰岩,岩溶发育,设计采用了预注浆及抛填片石粘土法或灌注低标号片石混凝土措施进行处理。

Overall Design of Bianyuzhou Changjiang River Bridge on Newly-Built Anqing-Jiujiang High-Speed Railway

The Bianyuzhou Changjiang River Bridge on the newly-built Anqing-Jiujiang Railway is designed to accommodate two lines of high-speed railway of 350 km/h and two lines of mixed freight and passenger railway of 200 km/h.The south navigational channel bridge is a two-pylon steel box hybrid girder cable-stayed bridge with a main span of 672 m and the stay cables are crossed,forming network cable planes.The north navigational channel bridge is a single pylon prestressed concrete girder cable-stayed bridge with two main spans of 140 m and the stay cables are arranged in harp formation.The part of Bianyuzhou and the north non-navigable spans adopt the simply-supported bridge with typical span length of 48 m,the part crossing the north embankment adopts the variable-height continuous beam bridge with a main span of 100 m,the south and north approaches,apart from the continuous beams,adopt the standard railway beams with span lengths of 32 m and 24 m.The foundations are pile foundations.The south and north navigational channel bridges have one integrated deck,while the remaining has separated two decks.To address the limestone with characteristics of karst development at the bridge site,the ground is treated by pre-grouting,filling with rubbles and clay or casting low-grade concrete with rubbles.