Effect of bed dredging near to existing retaining wall based on experimental study

Dredging is usually used in constructing the buildings’ basements and causing large failures in the existing retaining walls. This study is about the behavior of retaining walls as a result of bed dredging through many experimental tests. The dredging system has been performed by using a suction system via vacuum air. This study was carried out by varying the ratio of the dredging depth to wall width (Y/B w ), the ratio of the distance from the bed of wall to wall width ( b / B w ), the slope of dredging, live load acts on the top of retaining wall, and the relative density of sand ( D r ). The ultimate live load lowered by about 34.14, 24.26, 23.16, 13.28 and 1.21% with varying the ratio of the distance from the bed of wall to wall width ( b / B w ) of 0.25,0.50,1.00,1.50 and 2.00, respectively, at constant values of slope 2 H :1 V , Y / B w = 1/3 and D r = 50%. However, at D r = 80%, it becomes 32.36, 18.39, 17.65, 8.00 and 0.74%, over that without dredging case. The results showed that the relative density and the distance from the bed of the wall have a significant effect on the wall's stability as aresult of dredging the bed.