涌浪作用下浮吊安装钢塔安全性评估研究

摘要

T he steel pylon of the River‐to‐Sea Ship Channel Bridge of the Hong Kong‐Zhuhai‐Macao Bridge ,which rises 106 m and weighs about 3 100 t ,was monolithically lifted and placed by the“changdahaisheng”and“zhengli”floating cranes with capacities of 3 200 t and 2 200 t ,respec‐tively ,and manufactured by the Guangdong Provincial Changda Highway Engineering Company and the Zhengli Ocean Engineering Company .To study the safety of the floating cranes under the action of swell ,the hydrodynamic analysis software HydroSTAR and mooring anchor Ariane 8 were used to establish the related three‐dimensional mesh models ,based on the hydrodynamic in‐terference theory for multi‐body floating system and the time domain theory for mooring anchor system .Under the most unfavorable load cases ,the rolling ,pitching and heaving motions of the floating cranes ,the load bearing capacity of the mooring anchor lines and the moving ranges at the locations of the two lifting hooks of the steel pylon influenced by different swell heights in different periods were analyzed .The results of the analysis indicate that the single ranges of the maximum transverse swings of the “changdahaisheng” and “zhengli” floating cranes are 2 .2° and 3 .0° ,re‐spectively .The single ranges of the maximum heaving oscillation are 0 .59 m and 1 .13 m ,respec‐tively .And the angle of the longitudinal swing is minimal .The maximum load bearing safety coef‐ficients of all the mooring lines are 2 .54 and 1 .80 ,respectively .T he maximum single range of the relative movement measured at the locations of the two hooks of the steel pylon is 2 .3 m .The cal‐culated values of the movement of the two cranes meet the requirements and the mooring system is safe and reliable .The operation limit conditions determined include the 0 .8 m high swell ,14 s pe‐riod and wind speed of 8 m/s .%港珠澳大桥江海直达船航道桥钢塔高达106 m ，重约3100 t ，采用3200 T“长大海升”与2200 T“正力”浮吊船整体吊装。为研究涌浪作用下船舶的安全性，基于多浮体水动力干扰理论和系泊系统时域分析理论，采用水动力分析软件 Hydro‐S T A R和锚系泊A riane8建立相应三维面元网格模型，选取最不利工况，对特定涌高在不同周期下船舶的横摇、纵摇及垂荡统计值，系泊线受力，以及钢塔2个吊钩处的相对运动幅值进行分析。结果表明：“长大海升”与“正力”的最大横摇单幅值分别为2．2°、3．0°，最大垂荡单幅值分别为0．59m、1．13m，纵摇角度很小，所有系泊线最大受力安全系数分别为2．54和1．80，钢塔上2个吊钩处的相对运动最大单幅值为2．3m ；2艘船运动统计值均满足要求，系泊系统安全可靠，确定作业限制条件为涌高0．8m，周期14s，风速8m／s。