The ‘safety valve’ of a dam is its
A spillway is a structure constructed at a dam site, for effectively disposing of the surplus water from upstream to downstream. Had there been no such structure, the water level must have exceeded maximum reservoir level, and ultimately would have crossed the freeboard and thus overlapped the dam, causing the failure of the dam. Hence a spillway is essentially a safety valve for a dam.
Which one of the following spillways is least suited to earthen dams?
The spillway which can be adopted with ease on gravity as well as earthen dams, is
An ogee spillway is mostly suitable for concrete gravity dams especially when the spillway is located within the dam body in the same valley. The trough spillway or chute spillway is the simplest type of a spillway which can be easily provided independently and at low costs. It is lighter and adaptable to any type of foundations and hence provided easily on earth and rockfill dams.
The famous Bhakra dam of our country has been provided with
In computing the spilling capacity of high ogee spillways, the velocity head is usually
The portion of a chute spillway, which is known as its Control structure, is
The spillway, which can be called as an ‘overflow spillway’, is essentially
The spillway, which may sometimes be called a ‘waste weir’, is
The spillways involving weir type spills, giving increased discharge with the increase in reservoir level, are
A shaft spillway is located