USBR ch 6 Flashcards
The reason the earthfill dam is the most common type of dam is because its construction involves using materials in their unnatural state with more processing
T or F
False
The essential requirements of the foundation for an earthfill dam is that it provide stable support for the embankment under all conditions of saturation and loading, and that it provides sufficient resistance to seepage to prevent excessive loss of water
T or F
True
The purpose of grouting a dam foundation is to act as a bender and fill in the voids in the foundation
T or F
True
The purpose of toe drains is to give the operator an elevation reading
T or F
False
What are some disadvantages of grout caps
a) decreased costs associated with excavation and concrete
b) creates potential low gradient at contact with zone 2
c) excavation for the cap may disturb (damage) foundation
d) both A and B
c) excavation for the cap may disturb (damage) foundation
The methods of treating salt and clay foundations are based on the soil type and location of water table and the density of the soild
T or F
True
Why can’t a designer of an earthfill dam rely on the application of mathematical analysis or formulas to determine the required cross section to the degree that one can for a concrete dam?
a) soil occurs in infinite combinations of size gradation
b) composition
c) corresponding variations in behavior under different conditions of saturation and loading
d) all above
d) all above
In reference for dams, “freeboard” means the vertical distance between the crest of the embankment and the reservoir water surface
T or F
True
Name some material used for upstream slope protection on earthfill dams
a) steel facing
b) soil-cement pavement
c) rock riprap (riff raff)
d) precast concrete blocks
e) concrete pavement
a) steel facing
b) soil-cement pavement
c) rock riprap (riff raff)
d) precast concrete blocks
e) concrete pavement
Rock for riprap should be hard, dense, and durable. It should be able to resist long exposure to weather. What type should be used?
a) limestone
b) sandstone
c) concrete rock
d) both A and B
d) both A and B
