Question

During the construction of an earthen dam by hydraulic fill method, development of pore pressure becomes important in the __________________

(a) central impervious core

(b) pervious outer shell

(c) transition zone

(d) both central core and outer shell

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The origin of the question is Types of Earthen Dams topic in division Earthen and Rock Fill Dams of Irrigation Engineering

Answer 1

The correct option is (a) central impervious core

Explanation: In this method, an embankment is created by water and earth slurry which is discharged inwards to form a central pool at site. When water is pumped to the site it spreads the coarser material drops out first and the finest at last. Thus the core material settles within the central pool forming a zoned embankment and high pore pressures develop in the core.