有压洞内泥沙起动试验研究

Experimental Study on Sediment Incipient Motion of Pressured Tunnel

为研究有压洞内泥沙起动规律,对14组不同粒径泥沙颗粒进行有压洞内泥沙起动试验,得到其对应的泥沙起动断面平均流速,与一般情况下泥沙起动流速对比发现相同粒径泥沙颗粒在有压条件下较普通明渠容易起动。将推导得到有压洞内泥沙起动断面平均流速公式与其他公式进行比较,发现所构建公式的计算值与实测值吻合较好,可见利用该公式计算有压洞内泥沙颗粒起动流速较为合适。

In order to study the law of sediment incipient motion of pressured tunnel, laboratory experiments were carried out by using 14 groups of sediment particles with different particle size, and the corresponding average velocity of sediment incipient motion was obtained. It is found out that there is a certain difference between the sediment incipient motion of pressured tunnel and that in open channel. Comparing with the other starting formulas, the calculated values of the proposed formula are in good agreement with the measured values. Therefore, it is more appropriate to calculate the incipient velocity of pressured tunnel by using the proposed formula.