渤海莱州湾和黄河口附近海冰剪切强度的试验研究

Experimental studies of the shear strength of sea ice in the Laizhou Bay and around the Yellow River Delta of Bohai Sea

剪切强度是海冰的基本力学性质,直接影响到冰区结构物冰荷载的确定以及海冰在动力演变过程中的破坏行为。采用侧限单面剪切试验对渤海莱州湾和黄河口的海冰进行了剪切强度测试,分析了温度、卤水体积、剪切应力率的影响。结果表明,海冰剪切强度随冰温的降低和剪切应力率的增大而呈线性增长,而与卤水体积的平方根呈幂函数降低。在此基础上,综合考虑卤水体积和剪切应力率的影响,对海冰剪切强度进行了双参数拟合,为研究海冰剪切破坏机理提供了参考依据。

The shear strength is the basic mechanical property of sea ice, and affects the ice load on offshore structures and the breakup behavior of ice cover in the sea ice dynamic process. In this paper, the shear strength of sea ice is determined through single plane shear test with lateral confinement. The ice samples were collected from the Laizhou Bay and the Yellow River Delta of Bohai Sea. The influences on sea ice shear strength of ice temperature, brine volume and shear stress rate were analyzed based on the experimental results. The shear strength increases linearly with the decreasing ice temperature and the increasing shear stress rate, while it decreases exponentially with the square root of brine volume. Moreover, the prediction function of sea ice shear strength was fitted considering the influences of both brine volume and shear stress rate comprehensively. This study provided a basis for investigating the shear failure mechanism of sea ice cover.