铺砂驳分层回填工艺在大面积水下摊铺砂垫层项目的应用

Application of layered filling technology of spreader pontoon in underwater large-area sand blanket paving project

针对香港国际机场第三跑道填海工程回填区域原始海床泥面为淤泥底质,强度极低,为避免出现挤淤及地基失稳现象,提出采用分层回填方式进行水下抛填。针对项目设计文件要求在原始海床面铺设2 m厚的砂垫层且每层厚度不超过0.5 m,提出采用铺砂驳进行水下分层精抛砂垫层的施工方案,有效解决了水下薄层精抛及严苛的环保要求等一系列问题,实现水下大面积高效率环保铺砂作业,施工质量检测效果良好。该工艺为国内外同类型项目提供了很好的工程借鉴和技术参考。

In view of the fact that the original seabed mud surface in the backfilling area of the main reclamation works of Hong Kong International Airport three runway system project is deposit marine mud with extremely low strength.In order to avoid silt squeezing and unstable foundation,the layered filling method was proposed for underwater dumping.According to the requirements of the project design documents,2 m thick sand blanket should be laid on the original seabed surface,and the thickness of each layer should not exceed 0.5 m.The construction scheme of using spreader pontoon to carry out underwater layered fine sand throwing cushion was proposed,which effectively solves a series of problems such as underwater thin-layer fine sanding and strict environmental protection requirements,realizes underwater large-area high-efficiency environmental protection sanding operation,and the construction quality detection effect is good.This process provides a good engineering and technical reference for similar projects at home and abroad.