黏土中隔舱吸力式钢圆筒安装及水平受荷试验研究

近年来大直径钢圆筒结构在离岸人工岛工程中得到应用，如港珠澳大桥人工岛即采用振动下沉的方式安装钢圆筒，该方法对施工条件、装备以及施工控制技术要求较高。提出一种新型隔舱吸力式钢圆筒结构，在钢圆筒内部设置隔舱板，将结构分为上下两个隔舱，通过对下舱抽气实现隔舱吸力式钢圆筒在负压作用下的下沉安装。设计了隔舱吸力式钢圆筒安装及水平承载力模型试验，对比了负压贯入的隔舱吸力式钢圆筒和压力贯入的传统钢圆筒结构的贯入阻力及承载特性，分析了改变隔舱吸力式钢圆筒上下舱高度比L₁/L₂对其沉贯过程及承载特性的影响。结果表明，采用负压吸力沉贯的隔舱吸力式钢圆筒相比于采用压力贯入的传统钢圆筒结构的贯入阻力减小，水平极限承载力提高。在极限水平荷载作用下，随着隔舱吸力式钢圆筒的L₁/L₂从2.28减小到1.00、0.56，转动中心位置上移，水平极限承载力及弯矩承载力得到显著提高。

Model tests on installation and horizontal bearing capacity of compartment suction steel cylinder in clay

In recent years, large-diameter steel cylinder structure has been widely used in offshore artificial island projects. For example, the artificial island of Hong Kong-Zhuhai-Macao Bridge adopts the vibration sinking method to install steel cylinder. This method has strict requirements for construction conditions, equipment and control technology. A novel type of suction steel cylinder with compartments was proposed in this research. A partition plate was arranged inside the steel cylinder, dividing the structure into upper and lower compartments. By pumping air to the lower compartment, the compartment suction steel cylinder can be installed with negative pressure. The installation and horizontal bearing capacity model tests of the compartment suction steel cylinder were designed, the penetration resistance and bearing characteristics of the compartment suction steel cylinder with negative pressure penetration and the traditional steel cylinder with pressure penetration were compared, and the influence of changing the upper and lower compartment height ratio L₁/L₂ on the penetration process and bearing characteristics of the compartment suction steel cylinder was analyzed. The results show that compared with the traditional steel cylinder structure with pressure penetration, the penetration resistance of the compartment suction cylinder with negative pressure penetration is decreased, and the horizontal ultimate bearing capacity is increased. Under the ultimate horizontal load, as the L₁/L₂ of the compartment suction steel cylinder decreases from 2.28 to 1.00 and 0.56, the rotation center moves upward, and the ultimate bearing capacity and bending moment significantly increase.