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Design and Construction Guidelines for Dams in Texas


Quiz Questions

1.Dams fall under the jurisdiction of the TCEQ Dam Safety Program if they are used as a pumped storage or terminal storage facility.
True
False
2. Construction plans for a proposed dam must include: a vicinity map, topography map, profile of the dam, profile of each spillway, log of all borings and the cross-section of the dam.
True
False
3._____________ dams include gravity, arch, buttress, masonry, and roller-compacted concrete (RCC) dams.
Concrete
Embankment
4. _______________dams are best suited for in-channel overflow structures, as well as narrow gorges.
Concrete
Embankment
5.For many small-sized embankment dams, determining the feasibility necessitates a review of the commonly available data, including: maps, well and spring data, geological surveys, construction records of nearby structures and the presence of adequate soils.
True
False
6.Proper treatment of a dam foundation should ensure that it has either (1) sufficient control of seepage waters beneath and around the dam, and (2) adequate structural provisions to prevent its displacement or deformation, whether or not the reservoir is impounding water, and under both dry and saturated conditions.
True
False
7. _____________________ foundation can be alluvial foundations or rock foundations with joints, fissures, crevices, permeable strata, fault planes, etc. This condition can result in seepage that causes erosion and/or excessive uplift pressure.
Saturated
Permeable
8.Weak foundation is a condition that can be caused by the presence of cohesion less or dispersive soils, slaking shale, gravelly materials, or clean, saturated sand of very low density.
True
False
9.Test borings must either penetrate into competent bedrock or penetrate to a depth of 1.5 times the height of the dam (depending on whichever is less).
True
False
10.A stability analysis is required for proposed small, low-hazard embankment dams with upstream and downstream slopes flatter than or equal to 3 Horizontal to 1Vertical.
True
False
11.In Embankment dams, the allowable bearing capacity (of foundation) must not exceed 1/3 of foundation’s ultimate bearing capacity and must account for eccentric and inclined loadings, as well as other appropriate factors.
True
False
12.The most common type of dam in Texas is the embankment dam, which is usually the most economical choice, utilizing locally available materials. Although its requirements for an adequate foundation are not as extensive or critical as for a concrete dam, an embankment dam is nonetheless more susceptible to erosion and requires continuous maintenance, including substantial vegetation control.
True
False
13.A zoned embankment dam typically includes (at a minimum) a core zone of impervious material with a cross-sectional thickness sufficient to adequately control seepage. The core zone is most often centrally located beneath the embankment crest; however, the core zone may sometimes be offset or located on the upstream side, and it may be vertical or inclined.
True
False
14.A _____________________may be solid or hollow, it may consist of masonry or more commonly of concrete, and it always requires an impervious foundation of high bearing strength. This dam  must account for the tensile forces at the upstream face due to the hydrostatic pressure, and it must effectively handle the compressive forces at the downstream face without the dam sliding, overturning, or crushing the downstream toe.
Roller-compacted concrete dam
Gravity dam
15.Replacing a conduit via the slip-lining method involves pulling or pushing a smaller-diameter conduit through the damaged conduit, and then sealing the resulting annular region between the two conduits with grout. When slip lining a horizontal conduit that is connected to a riser, a concrete or grout plug must first be placed in the local annular region at the junction of the horizontal conduit and riser before the remainder of the annular region can be sealed with grout.
True
False