Pile Driving Inspection Flashcards

What is the minimum distance from a previously driven pile that a new pile can be driven without risk of damage?

Answer: Specified in the contract documents and geotechnical report

The minimum driving spacing is specified in the contract documents and geotechnical report based on soil conditions, pile type, and structural requirements.

What is the purpose of measuring pile 'cutoff elevation'?

Answer: To determine how much pile must be removed after driving to match the design structural connection point

Cutoff elevation is the design elevation at which excess pile above the pile cap is removed, ensuring the pile connects to the structure at the correct point.

What is a 'restrike' in pile driving and when is it performed?

Answer: Re-driving a pile after a waiting period to assess capacity after soil setup

A restrike is the re-driving of a pile after a waiting period (typically 24–72 hours) to assess how soil setup (freeze) or relaxation has changed the pile's capacity since initial driving.

What type of pile is most commonly used in FDOT bridge foundation construction?

Answer: Prestressed concrete piles

Prestressed concrete piles (square or cylinder) are the most commonly specified pile type in FDOT bridge foundation work due to their durability in Florida's marine and corrosive environments.

What is 'driving resistance' in pile driving inspection?

Answer: The resistance of the soil to pile penetration, measured in blows per foot or inch

Driving resistance is the measured resistance of the soil to pile penetration during driving, quantified as the blow count per unit of pile penetration.

What document should an inspector review before pile driving begins to understand subsurface conditions?

Answer: The geotechnical investigation report and boring logs

The geotechnical investigation report and soil boring logs describe subsurface conditions along the pile alignment and are essential for anticipating driving behavior and verifying performance.