沉管隧道管节出坞、拖航、系泊与沉放准备关键问题

Immersed tunnel HZMB docking-out,towing,mooring and immersion preparation critical issues

港珠澳大桥岛隧工程的沉管隧道安装了33个沉管管节。因骤然的回淤,2次回拖,所以总共进行了35次安装作业。在沉放作业前,需要将预制厂的干坞内漂浮着的沉管管节绞移出坞。在坞口解除系泊状态并连接拖轮。然后在受限的航道内拖运11 km直到隧道的所在地。并再次系泊管节以准备沉放作业。第二次系泊是横流定位。对这个从系泊到系泊的过程需控制风险。文章总结成功实施背后的对该问题的思考,方案制定的原则,以及决定成败的细节。

The Hong Kong-Zhuhai-Macao Bridge( HZMB) island and tunnel project had completed the immersion of 33 elements. Due to sudden sedimentations,an element was towed back for two times,so 35 times of installation were made. Before immersion,the element was transported from sheltered dry dock to tunnel site. This process has risk that element may be out of control: In warping out,the element’s position was affected by current;in towing,the element’s draft is constraint by water depth;in mooring for the immersion preparation,the element’s long direction is in perpendicular to the attacking current. The risk of the above processes much be controlled. In this paper,the thinking of engineering problem was summarized. The principle of making novel solution and the details of implementation were reviewed.