港珠澳大桥海底沉管隧道基础垫层选型与总体设计

General design and type selection of foundation bedding of undersea immersed tunnel for Hongkong-Zhuhai-Macao Bridge

对港珠澳大桥海底沉管隧道可选的基础垫层进行多方面比选分析,提出了采用先铺碎石垫层作为隧道结构与地基之间的过渡构造。通过与国外类似工程设计进行比对,结合垫层受力作用机理,从横向、纵向及竖向3个维度对垄沟相间碎石垫层的几何参数进行设计,并通过物理模型试验确定了碎石垫层的物理力学指标。工程实践检测表明,先铺碎石垫层各项指标均能满足设计要求,施工工序衔接合理,是一种可检、可达、可修的沉管隧道垫层,可在类似工程中推广应用。

Based on the comparison and analysis of the foundation bedding of undersea immersed tunnel for Hongkong -Zhuhai-Macao Bridge, we proposed the gravel bedding as the transition layer between the tunnel structure and foundation. Bycomparing with the foreign similar engineering design, we designed the geometric parameters about the transverse, longitudinaland vertical sides based on action mechanism of gravel layer with ridge and groove, and determined the physical andmechanical indexes by the physical model test. Practical testing show that gravel bedding can meet the design requirements,reasonable construction process connection, which is a kind of underwater structure with the features of detectable, reachable,repairable, it is valuable to popularize and use in similar projects.