Carsington Dam Failure

Carsington Dam Failure

1. Location2. Background3. What happened on the day4. Effects of the dam failure5. What caused the Dam failure

Location & Background

• The dam is located by the river Derwent• 3 other dams are located and are directly supplied by the river• The river is an indirect supply

-it’s a lake-pumping station

• Built to regulate flow• Planning started in 1960s• Provides water for three million people

What happened?

• The upstream slope of Carsington Dam failed just before its completion in 1984

• Occurred in June and was sudden and catastrophic • The slip started on the right abutment and spread across the

valley to a length of nearly 500m• At its peak, the slip was moving at 120mm per hour.

The Cause

• Two different figures of Factor of Safety were used• Requirements for testing and removing clay from the

foundation were inconsistent• None of the assumed slip surfaces, passed through the core• The core itself was oddly shaped• Shearing through the core • Solifluction shears