SCOUR DOWNSTREAM OF CAUSE-WAYS

Abstract

There exists an obvious choice for bridging the natural channels by using a high level structure. However, often due to financial constraints and inadequate fund availability for road development, the engineer is forced to consider options like providing a cause-way in place of the bridge. Such crossings necessarily entail disruption in the existing traffic during high flood conditions. However, these structures are useful due to savings in the cost and where the disruptions are within a certain acceptable limits. There are various parameters that affect the hydraulic design of cause-way. Depth of scour is an important parameter that is needed for the design of foundations of the cause-way and its protection works. Till now Lacey's method is used for the determination of normal scour depth below high flood level as per Indian Road Congress guidelines 0: no relationship specifically for cause-way scour exists. Therefore, There is need for the studying the phenomenon of scour downstream of cause-ways. In present study an experimental investigation has been carried out concerning scour below a cause-way. 42444444,i4pf the temporal variation of scour depth and the latof 64n) equilibrium scour depth A, studied. The available equation for scour depth due to jet flow is also found to satisfactorily estimate the scour depth occurring below the cause-way studied herein.