锚墩预施拉力精确定位钢吊箱围堰施工技术

武汉天兴洲公铁两用长江大桥2号主塔墩基础大型钢吊箱围堰采用工厂整体制造,下河浮运至墩位,利用锚墩施加预拉力精确定位的施工新工艺。钢吊箱围堰同时用作钢护筒插打导向架、钻孔桩施工平台及承台施工的防水围堰。本项新技术可运用于水流方向多变、水位变化大的河段及近海跨江跨海特大型桥梁深水基础钻孔桩及高桩承台施工。

Construction Technique for Accurately Positioning Steel Boxed Cofferdam by Pre-Tensioning at Anchor Pier

The new construction technique applied to the huge steel boxed cofferdam for foundation of pylon pier No.2 of Wuhan Tianxingzhou Changjiang River Rail-cum-Road Bridge was to fabricate the cofferdam in integrity in workshop,shift it down to river and float it to the pier site where it is then accurately positioned by pre-tensioning at the anchor pier.The cofferdam could be concurrently served as a guiding frame for setting and driving bored pile steel casings,a working platform for construction of bored piles and water-retaining facility for construction of pile cap.The construction technique in question is applicable to the river reach where water current directions and water levels are varying and to the construction of bored piles and elevated pile caps for deep water foundations of major bridges over river and sea in the offshore area.