外海人工岛岛头区碎石垫层防淤减淤

Anti-silting and silting reduction of gravel cushion in the head area of the artificial island of open sea

港珠澳大桥E33沉管位于外海东人工岛西侧,受大屿山沿岸流和东人工岛岛头挑流影响,安装区流场复杂,碎石垫层回淤大。为了降低回淤对沉管安装的影响,开展了东岛岛头区碎石垫层防淤减淤综合治理措施研究,采用防淤盖板和防淤屏对E33沉管碎石垫层进行防淤减淤,并进行了现场大规模的试验验证,对潮位、海水浊度等一系列实时观测。经过多种手段监测显示,防淤盖板和防淤屏有效控制了E33对接段回淤影响,降低了沉管安装的风险。

The E33 caisson of the HZMB is located on the west side of the east artificial island of the open sea. Affected by the flow along the Lantau Island and the overflow in the head area of east artificial island, the flow field in the installation area is complex and the gravel cushion is silted back heavily. In order to reduce the influence of siltation on the installation of immersed tube, the comprehensive control measures for anti silting and silting reduction of gravel cushion in the head area of east island are carried out. The silt prevention cover plate and the anti silting screen are used to prevent and reduce the siltation of E33 immersed tube gravel cushion, a large number of experiments are carried out on site, and a series of real-time observations of tidal level and turbidity are carried out. Monitoring by various means shows the silt prevention cover plate and the anti silting screen effectively control the siltation of the butt section of the E33 and reduce the risk of the installation of the immersed tube.