Author(s): Peyman Modaber Dabbagh; Mojtaba Saneie; Mohammad Rostami; Mohammad Mehdi Razmi
Linked Author(s):
Keywords: Local scour; Bridge lateral abutment; Non-submerged pile; River engineering
Abstract: Scour around hydraulic structures is an inevitable phenomenon. Recognizing this phenomenon and dealing with it is an issue upon which the plan’s success is warranted. Local scour at the abutments is reported as the most significant cause of bridge failures. Utilizing submerged and non-submerged piles are one of the scour countermeasure methods. Non-submerged piles are rarely used in investigating the amount of scour. In the present study, the results obtained from a series of tests performed with diverse flow rates (3flow rate) and different number of piles (non-submerged ones), (6 and 7 piles) with different locating distance (5 types), at the bridge lateral abutment, is presented. The tests have been carried out in clear water conditions and in a flume with 14 meters length, 60 centimeters wide, and 60 centimeters height. The findings show that the number of piles and their locating distance from the wall have great influence on the reduction of abutment scour. And experiments showed that the highest reduction in the maximum scour depth and volume occurs when 7 piles with no distance from the side of flow path are used. By increasing the flow rate, reduction percent of the maximum scour depth and volume increases. Using piles result in scour volume reduction from 18% to 80% as well as maximum scour depth reduction from 18% to 70% . The more values are related to “type I” in which “7 piles” are used in linear form and without distance from the side of flow path. The lower values are related to “type III” where “7 piles” with a two-pile diameter distance from the side of the canal are used. (In all of the tests, piles distance of abutment is two times an abutment length and it is fixed).
Year: 2013