云南红河特大桥加劲梁施工方案研究

云南红河特大桥主桥采用单跨700m的悬索桥,加劲梁采用整体式流线型扁平钢箱梁结构,共59个梁段,标准梁段长12m,最大梁段重144.3t。针对桥址区地形陡峻,加劲梁节段运输、吊装难度大等难点,采用缆索吊机吊装加劲梁,缆索吊机跨度布置为(315.2+700+166.1)m,额定吊重160t;设计一套自动化旋转吊具调整加劲梁的方位,以满足吊装纵移空间的要求;斜拉扣挂式墩旁起吊平台由桥塔下横梁墩旁托架、先吊装的端部2个梁段及斜拉扣索组成。端部梁段采用缆索吊机结合纵向牵引荡移装置倾斜吊装;其余梁段利用斜拉扣挂式墩旁起吊平台垂直起吊,从跨中往两岸对称吊装,梁段间采用"全铰法"进行临时连接;合龙段位于两端,利用设于墩旁托架上的三向千斤顶调整对接。

Study of Construction Schemes for Stiffening Girder of Honghe River Bridge in Yunnan

The main bridge of Honghe River Bridge in Yunnan is a suspension bridge with a single span of 700 m.The stiffening girder is formed of the integral streamlined flat steel box segments.A total of 59 segments are used,among which the standard segments are 12 m long and the longest segment weighs 144.3 t.The rugged ground condition at the bridge site makes the transportation and erection of the girder segments quite challenging.The scheme of using cable cranes to hoist the stiffening girder is adopted.The cable crane can cover three spans of 315.2,700 and 166.1 m,with a specified hoisting capacity of 160 t.A set of automatic rotary equipment is deployed to adjust the position of the stiffening girder,so as to create sufficient room for the longitudinal movement during the hoisting operation.The pier-side hoisting platform of a tie-back type consists of pier-side brackets at the location of lower cross beam of the towers,the two end starter segments and the fastening stays.The end girder segments are hoisted in slant manner by using the cable crane with the assistance of the longitudinal dragging and swinging devices.The remaining girder segments are vertically hoisted using the pier-side hoisting platform of tie-back type,proceeding symmetrically from the midspan towards the two banks.The adjacent girder segments are temporarily connected by the“full hinge method”.There are two end closure segments,which are adjusted and butt-jointed by the three-directional jacks located on the pier-side brackets.