中文摘要：

目前正在施工的港珠澳大桥沉管隧道位于珠江三角洲径流的影响范围内，为了掌握大径流对沉管安装的影响，开展了潮位、流场和海水密度等一系列实时观测。通过现场实测，珠江三角洲汛期带来的大径流，一方面影响流速，另一方面影响海水密度和浊度等。大径流对沉管施工影响显著，尤其对沉管浮运拖航和沉放对接等关键工序影响极大。

英文摘要：

The Hongkong-Zhuhai-Macao Bridge immersed tunnel project under construction is in the range of the influence of Pearl River Delta’s runoff. In order to get the large runoff effects on immersed tube installation, we carried on a series of observation and research on tide, current, and seawater density. The large runoff from Pearl River Delta flood season has influence on current, seawater density and turbidity within actual measurement. It has a great influence on the immersed tunnel construction, especially on the key processes of immersed tube floating and sinking.