混合梁斜拉桥索塔与下横梁异步施工控制分析

摘要

A bridge is used with the diamond type concrete pylon, and its total height is 177.91 m.In the intersection position of the Middle-Pylon and the Down-Pylon is the bottom end rail.The construction method of the pylon and bottom end rail are asynchronous constructed, which is we put the middle-pylon into the second construction segment, and then go on the bottom end rail.During the peri-od, pylon will appear cantilever state, so the weak section prone to tensile stress;it is to be avoided in the bridge construction.The pur-pose of this paper is to simulate asynchronous process, to analyze the influence to the tower, and to give the corresponding construction measures.%某特大桥索塔采用钻石型混凝土索塔，索塔总高度为177．91 m，在下塔柱与中塔柱相交位置设置一道下横梁。施工中塔柱与下横梁采用异步施工，即先将中塔柱施工到第二节段再进行下横梁施工。期间，索塔会出现悬臂状态，故索塔的薄弱截面易出现拉应力，这在桥梁施工中是要避免的，为此，先通过模拟分析异步施工过程对索塔的影响，给出相应的施工控制措施。