基于声纳技术的截流深井淤积研究

Research on Siltation Condition of Deep Intercepting Wells Based on Sonar

在排水设施检测中，声纳探测是一种方便高效的检测方法。在柳州市河北环岛截污工程的壅水式截流深井的淤积状况检测中采用了声纳检测系统，探测结果显示：壅水式截流深井内已形成较严重的淤积，淤泥厚度为1．1～1．9m；截流深井的淤泥面呈现出相似的形状，纵向淤泥面呈斜坡状，坡度一般在30°左右，横向淤泥面呈凹面锅底状。经分析，壅水式截流深井淤积的原因主要是由于溢流堰的阻挡，使水流方向由水平变为上升；此外，截流井室过水断面面积较大导致的水流速度长期小于不淤流速，也是截流深井发生淤积的重要原因。

Sonar system is a convenient and efficient tool to inspect drainage facilities. Sonar system was used to inspect the siltation condition of deep intercepting well with damming in the sewage inter- ception project around island of north river in Liuzhou City. The inspection results prove that there is serious deposition with silt depth between 1.1 m and 1.9 m in the deep intercepting well with damming. The silt surface shape in deep intercepting wells is similar, that is, the longitudinal silt surface is a slope with about 30 degree gradient, and the transverse silt surface is a concave surface as hollowware bottom. After analysis, the reason of siltation in deep intercepting well with damming is that the flow changes from hori- zontal direction to vertical direction because of the obstacle of overflow weir. Furthermore, it is another major cause contributing to siltation that the flow section in intercepting room is larger and then the flow velocity is less than non-sihing velocity in long term.