Engineered Structures

A structure that supports the end of a dam

A relatively narrow, horizontal bench built along an embankment

The roof of a mine

An impermeable structure placed beneath the base of a dam to prevent or reduce seepage loos. The structure may be made of concret, compacted clay or grout.

The flat top of a dam

Soil that flows into a tunnel from the floor, roof, or walls of a tunnel driven by water seepage. The flow typically consists of cohesionless soil below the water table.

Vertical distance between the dam crest and the water surface of a reservoir

A cement slurry of high water content used to seal fissures

A grout barrier used in the vicinity of tunnels or dams where cracks or joints in rocks are filled with a liquid cement that is pumped or poured into spaced to seal them

A mixture of Portland cement, sand, and water applied by pneumatic pressure through a special hose onto mine timbers, tunnel supports, and roadways to seal and fireproof them.

The floor or bottom of a closed conduit, such as a tunnel, aqueduct, or drain

Boards which are joined, side-by-side, lining an excavation

Seepage line. The uppermost level at which flowing water emerges along a seepage face.

Erosion by percolating water or seepage in a layer of subsoil resulting in caving and the formation of tunnels or pipes through which the soluble or granular material is removed.

Wells drilled at the toe of the dam to reduce the uplift pressure and prevent piping

Areas within the dam where excavated materials are placed. A random zone is placed where permeability and shear strength are not critical and where weight is important

Rock or soil that drops out of the roof or walls of a tunnel over time

A loose assemblage of broken rocks used for foundations or slope protection

Rock Quality Designation. A percentage of intact rock core (>=4inches) to the total length of the core run.

Soil that runs into the tunnel after removal of roof and wall supports; typically dry cohesionless sand.

Gunite that commonly included coarse aggregate up to about 1 inch (2cm)

Disintegration of rock or soil when submerged in water. Outcrops of sound rock when subjected to a shrink swell cycle crumble into flakes or particles.

A channel for reservoir flow

Soil or rock that creeps into a tunnel and maintains constant volume

Rock or soil that increases in volume when excavated. Volume increase is usually caused by the presence of clay minerals with a high swelling capacity.