关键词: 环境工程, 泥石流, 阻塞大河, 堵河模式, 堵河因素

Abstract: Large-scaled flumes were used to reproduce the confluence process of the main river blocked by high density viscous debris flow when the intersection angle was 90°. In the experiment, the amount and the unit weight of debris flow were variants. Based on the experiment data, three types of the river-blocked by debris flow were summarized: total blocking by submerged dam, partly blocking by sand dam and completely blocking by sand dam. Furthermore, their characteristics were analyzed respectively. And the influence factors of the large river blocked by debris flow were analyzed. The analysis results show that: the unit weight of debris flow influences the characteristics of the confluence movement and the river-blocking pattern of debris flow; the influence of the main river width on the river blocking is reflected in the flow distance of debris flow and the change of the hydraulic condition of the main river. Because of the width and the strong hydraulic condition of main river, the main river is difficult to be totally blocked, and is always partly blocked by sand dam. Total volume of debris flow has significant influence on blocking large river, and the rive blocking becomes more serious with the total volume of debris flow increasing. When R is more than or equal to 0.80, the solid material of sand dam runs off seriously and the value of backwater height of upstream presents exponential correlation with block coefficient.

Key words: environmental engineering, debris flow, large river blocking, model of river-blocked, factors of river-blocked