Horizontal drains are appropriate for

Horizontal drains are appropriate for

• A. Stabilization of a Hillslope
• B. Draining a foundation
• C. Drilling groundwater wells
• D. Sampling soils

Answer: (A)

Horizontal drains are used to reduce pore-water pressure within a hillslope, lowering seepage forces and increasing soil shear strength to stabilize the slope. By intercepting subsurface water and providing a path to remove it, they lower the groundwater level in the slope and raise the factor of safety against failure. This approach directly targets the water pressures driving instability, which is not addressed by draining a foundation, drilling groundwater wells, or sampling soils.

Horizontal drains are used to reduce pore-water pressure within a hillslope, lowering seepage forces and increasing soil shear strength to stabilize the slope. By intercepting subsurface water and providing a path to remove it, they lower the groundwater level in the slope and raise the factor of safety against failure. This approach directly targets the water pressures driving instability, which is not addressed by draining a foundation, drilling groundwater wells, or sampling soils.