波浪作用下大块石稳定性条件的研究,不仅是泥沙运动力学急待发展的内容之一,也是抛石工程合理化设计的重要问题。在收集大量国内外有关研究资料的基础上,分析了在波浪作用下大块石的受力状况,得出当大块石处于失稳临界状态时,其所受失稳应力与其自身有效容重和其当量直径乘积的比值是雷诺数、斯特鲁哈尔数及块石水下休止角的函数。为排除块石形状和块石间相互支撑形式不规则等干扰因素的影响,采用固定钢圈支撑孤立水泥砂球,在波浪槽中进行试验研究。根据试验资料,在斯特鲁哈尔数大于10的条件下,验证了当沙粒雷诺数达到105以后Shields曲线出现跳跃的事实。
Rubble stability under waves is one of the most immediate questions for kinematical mechanics of sediment. It will be bene- ficial to the optimization of riprap engineering design. In this paper, based on a large number of collected research data, the force con- dition of an isolated rubble under waves is analysed. When the isolated rubble comes under an unstable condition, the ratio of unstable stress to the multiplication of self weight and equivalent diameter is a function of Reynolds number, Keulegan & Carpente number, and the submarine rest angle. In order to overcome the influence caused by irregular rubble shape and contact forms, we use fixed steel rings to hold up the rubble in our wave flume experiment. The experimental results prove that the Shields curve would leap when Reyn- olds number is more than 105 under the condition of Keulegan & Carpente number over 10.