详情

原文传递 TESTING THE EFFECTIVENESS OF SCOUR COUNTERMEASURES BY PHYSICAL MODELING.

题名：	TESTING THE EFFECTIVENESS OF SCOUR COUNTERMEASURES BY PHYSICAL MODELING.
作者：	Eisenhauer-NO; Rossbach-B
关键词：	Bridges-; Case-studies; Countermeasures-; Durability-; Erosion-control; Floods-; Flumes-; Germany-; Riprap-; Scale-models; Scour-; Stability-Mechanics
摘要：	The physical modeling of the scouring process at bridge piers is a proven method to obtain information about the size of the scour and the flow velocities that generate the scour. On the basis of this information, appropriate countermeasures can be designed. The advantage of the physical model is its application to all, even the most complex, pier geometries. Because approach flow is uniform in most cases, physical model tests can be carried out in a hydraulic flume, a method that gives fast and reliable results. The Federal Waterways and Engineering Institute (Bundesanstalt fur Wasserbau) in Karlsruhe, Germany, conducted such model tests using piers of a new bridge over the Rhine River between the cities of Mannheim and Ludwigshafen. Shortly after sheet piles were driven into the riverbed as a formwork for the lower part of the pier, severe scouring of the riverbed occurred. Consequently, the stability of the sheet pile formwork was endangered. The ad hoc countermeasure of placing riprap into the scour did not stop local scouring. An additional cover layer of coarser stones was placed on top of the previous layer, stopping the erosion process at mean flow. Model tests were conducted to estimate the durability and stability of the ad hoc countermeasure for flood events. The tests proved that the riprap was stable, even at flood events, and that the scour had shifted away from the pier to the joint between the riprap and the original riverbed. A flood event with a peak of 3 days above the tested flood water level occurred in March 1999. No negative effects on the riprap have been observed until now.
总页数：	Conference Title: Fifth International Bridge Engineering Conference. Location: Tampa, Florida. Sponsored by: Transportation Research Board
报告类型：	科技报告