复合筒基细砂地基波流冲刷过程及最大冲深研究

STUDY ON SCOUR PROCESS AND MAXIMUM SCOUR DEPTH OF FINE SAND COMPOSITE BUCKET FOUNDATION INDUCED BY WAVE AND CURRENT ACTION

针对某工程实例,建立波流作用下复合筒型基础地基冲刷的试验平台;选取1∶40、1∶60的基础模型,研究波浪与水流共同作用下基础周围地基的冲刷过程及最大冲刷深度,并与水流单独作用下地基的冲刷特性进行比较;采用系列比尺模型的方法,给出实际工程复合筒基周围地基的最大冲刷深度。通过物理模型试验分析发现:波流作用下复合筒型基础后方的地基最先发生冲刷,最大冲刷位置出现在基础后方;区别于水流单独作用下的冲刷,在波流作用下冲刷平衡时基础周围不同位置的地基都发生冲刷;波流作用下地基的最大冲刷深度约为水流单独作用下地基最大冲深的2/3,且波流作用下最大冲深的位置较水流单独作用时更偏向模型下。

A test site for scour experiments under wave and current action is built based on a practical engineering,and a series of model tests are performed in which the model scales of 1∶40 and 1∶60 are adopted. The scour process and maximum scour depth induced by wave and current are investigated,and the scour characteristics are compared with current-only conditions. The maximum scour depth of the seabed around composite bucket foundation is determined according to the results of series of scale model tests. It is captured from the experiments that the scour under wave and current begins from the behind of the model,and the maximum scour depth also locates at the behind. When it reaches an equilibrium scour time,the seabed all around the foundation is scoured,which is different from the equilibrium scour topography induced by current-only. The maximum scour depth under wave plus current is about 2/3 of the maximum scour depth induced by current-only,and the position of the maximum scour depth moves downstream.