港珠澳大桥沉管隧道合拢口水动力条件数值模拟研究  

Numerical Simulation of Hydrodynamic Conditions on Closure Gap of Immersed Tunnel in Hong Kong–Zhuhai–Macao Bridge

作　　者：何杰[1,2] 高正荣 辛文杰[1,2] HE Jie;GAO Zhengrong;XIN Wenjie(Nanjing Hydraulic Research Inst.,Nanjing 210029,China;Key Lab.of Hydrology-Water Resources and Hydraulic Eng.,Nanjing 210029,China)

机构地区：[1]南京水利科学研究院,江苏南京210029 [2]水文水资源与水利工程科学国家重点实验室,江苏南京210029

出　　处：《工程科学与技术》2019年第6期68-74,共7页Advanced Engineering Sciences

基　　金：国家重点研发计划(2017YFC0405900)

摘　　要：港珠澳大桥海底隧道采用沉管法施工,最终接头安装前会在两节沉管中间形成合拢口。龙口往往形成水流集中、流速急剧增加的现象,给最终接头的安装施工增加一定难度。本文通过建立沉管合拢口局部水域的3维水流数学模型,模拟了“水下龙口”区域特有的水流结构,分析了龙口水流流速与珠江口径流、潮差的相关关系。数值模拟研究结果表明:合拢口纵断面流速分布具有“表层大、底层小,落潮大、涨潮小”的分布特点;同级别径流条件下龙口水流随潮差的增大而增加,相同潮差条件下龙口水流会随上游径流量的增大而增加;最终接头安装使用的起重船距离龙口仅30 m,船头挑流作用使得龙口西侧局部水域流速急剧增加,但对龙口区域的水流条件影响较小。根据沉管合拢口区域的水动力条件数值模拟结果,论证了最终接头安装施工期间的外部水情条件与对应的时间窗口,为港珠澳大桥沉管隧道的最终贯通提供了技术支撑。The Hong Kong–Zhuhai–Macao Bridge submarine tunnel was constructed by the immersed pipe.Before the final joint is installed,a closure gap will be formed in the middle of the immersed pipe.The water flow is often concentrated in the closure cap with a fast increasing velocity,which adds difficulty to the installation of the final joint.In this article,a three-dimensional mathematical model of water flow in the local waters of the closure gap was established,and the flow structure in the closure gap area was simulated.The relationship between the closure gap water flow and the Pearl River runoff including the tidal range was analyzed.The simulation results showed that the surface velocity in the closure gap was greater than the bottom one,and the velocity of ebb tide was greater than that of flood tide.The closure gap water flow increased with the increase of the tidal range under the same runoff,and the closure gap water flow increased with the increase of the upstream runoff under the same tidal range.The crane ship used in the final joint installation were only 30 m away from the closure gap.The bowing action of the bow made the flow rate of the local waters on the west side of closure gap increase sharply,but it had less influence on closure gap water flow conditions.According to the numerical simulation results of the hydrodynamic conditions in the closure gap,the external water conditions and the appropriate time for the final joint installation and construction were determined,which provided technical support for the final completion of the Hong Kong–Zhuhai–Macao Bridge immersed tunnel.

关 键 词：港珠澳大桥 沉管隧道 3维水流模型 龙口 潮流 

分 类 号：P756[天文地球—海洋科学]