1.3. Impact Velocity and Hammer Selection

Try these first

1. 1.

   What is the minimum thickness of cushioning material recommended for concrete piles?

   Hint

   Think about the materials that protect the pile.

2. 2.

   Name one common cushioning material used in pile driving.

   Hint

   It's a natural material that can absorb shock.

3. 3.

   What is the recommended cushion thickness for concrete piles?

   • 5 cm
   • 10 cm
   • 15 cm

   Hint

   Consider the materials that protect the pile.

4. 4.

   Higher impact velocity leads to ____ stresses on concrete piles.

   • True
   • False

   Hint

   Reflect on the relationship between speed and stress.

5. 5.

   A concrete pile weighs 2,000 lbs and is to be driven into soil with an average resistance of 500 lbs per foot. Calculate the required hammer energy to reach a penetration of 4 feet using the Engineering News Formula.

   Hint

   Make sure to rearrange the Engineering News formula correctly!

6. 6.

   Discuss how selecting a hammer with a weight that is less than a third of the pile’s weight could pose risks during operation. Provide a hypothetical example.

   Hint

   Consider the relationship between weight, energy, and soil conditions.