Scouring is one of the major threats to the stability of bridge abutments constructed over rivers. The present study investigated the usefulness of abutment slots in reducing the scour depth around bridge abutments with vertical walls, experimentally. Nine experiments with no slot and hundred experiments with slots were conducted in clear water conditions. Four subcritical flow conditions (Froude number less than 1) were investigated. For each flow condition, 25 different slot models having different sizes, and vertical and horizontal positions were considered. The results indicated that the slots having heights equivalent to half of the flow depth are more effective in reducing scouring if they are located closer to the bed. Increasing the slot height improves the performance. The best performance is achieved when the slot begins from the water surface and extends below the bed (equal to the scour depth in the model without the slot). Further, the results showed that the greater the distance of the slot is from the abutment nose and closer it is to the channel wall, the more effective the slot would be. Therefore, the most effective slot model is the model in which the slot height equals the distance from the water surface to below the bed, and when it is attached to the channel wall. For different slot models, in different flow conditions, the percentage of reduction of scour depth varies from 20 to 100%.

冲刷是对河流上建造的桥台稳定的主要威胁之一。本研究通过实验研究了基台缝隙在减少带有垂直壁的桥基台周围冲刷深度方面的有用性。在清水条件下进行了9个无槽实验，有100个有槽实验。研究了四个亚临界流动条件（弗劳德数小于1）。对于每种流动条件，均考虑了25种不同尺寸，大小，垂直和水平位置的不同缝隙模型。结果表明，如果狭槽的位置接近流床，则其高度等于流动深度的一半，在减少擦伤方面更有效。增加插槽高度可提高性能。当缝隙从水面开始并延伸到床下时，可获得最佳性能（等于不带缝隙的模型中的冲刷深度）。此外，结果表明，槽距基台鼻部的距离越大，并且距通道壁的距离越近，槽效越高。因此，最有效的缝隙模型是其中缝隙高度等于从水表面到床下面以及其附着到通道壁时的距离的模型。对于不同的槽型，在不同的流量条件下，冲刷深度减少的百分比从20％到100％不等。结果表明，槽距基台鼻子的距离越大，并且距通道壁的距离越近，槽效越强。因此，最有效的缝隙模型是其中缝隙高度等于从水表面到床下面以及与床连接时的距离的模型。对于不同的槽型，在不同的流量条件下，冲刷深度减少的百分比从20％到100％不等。结果表明，槽距基台鼻子的距离越大，并且距通道壁的距离越近，槽效越强。因此，最有效的缝隙模型是其中缝隙高度等于从水表面到床下面以及与床连接时的距离的模型。对于不同的槽型，在不同的流量条件下，冲刷深度减少的百分比从20％到100％不等。