Channel Mining Induced Stream Bed Instability around Bridges

Withdrawal or mining of sediment from a river bed causes local hydraulic discontinuities in close vicinity of the section of withdrawal operation. Duration and magnitude of the rate of channel mining in conjunction with the local flow and bed material characteristics have a direct influence on stream bed equilibrium. The response of a stream against such an operation needs to be searched to examine the time-dependent variation of bed levels that may alter the bed stability and may pronounce local scour problems around nearby bridges. A flexible and user friendly computer program is developed for the analysis of one-dimensional quasi-steady morphologic changes around bridges on rivers having rectangular cross-sections with no flood-plains. The program is executed to observe the effects of governing variables on the phenomenon. With the application of the program, a designer may assess outputs concerning the foundation stability of bridges against channel mining operations.