Question

Why are weep holes provided at the back of retaining walls?

• A. To reduce the active earth pressure on the walls.
• B. To reduce the build-up of hydrostatic pressure.
• C. To provide better compaction.
• D. To increase the passive earth pressure.

Answer 1

The correct option is B To reduce the build-up of hydrostatic pressure.

Weep holes at the base of retaining walls are intended to bleed off excess moisture that collects behind the wall. Due to rise of water table, the pore pressure develops and it causes excessive hydrostatic pressure on the wall. To reduce the development of excessive lateral pressure, weep holes are provided.