开河期冰盖纵向冰缝形成机理

Mechanism of longitudinal-crack formation during river-ice breakup

春季河道武开河可能导致冰坝形成,至今仍缺乏以力学机制为基础的开河预测方法。春季河道径流增加导致与岸壁冻结的冰盖底部产生上举力,并引起纵向冰缝产生。利用力学分析中弹性基础上的梁理论对开河期冰盖纵向冰缝形成机理进行了研究,提出了纵向冰缝间距解析表达式,可用于开河期冰盖断裂预测。应用原型观测资料对提出的纵向冰缝间距理论表达式进行了验证分析。研究结果表明,开河期纵向冰缝间距计算值与实测值吻合较好。

The mechanical breakup of ice covers during spring often lead to the serious ice-dam formation. However, the method for predicting the ice-cover breakup based upon the mechanical principle is in short supply. In this paper with the mechanical-analysis methodology the mechanism of the longitudinal-crack formation during the river-ice initial breakup is fully investigated by using the theory of beams on elastic foundation. A theoretical expression for predicting ice-cover breakup is presented. The comparison with the field observations indicates that the presented formula can to predict the location accurately.