1 / 15

Pile Foundations Module #9

Pile Foundations Module #9. Prepared by Dr. Randy R. Rapp July 2005. Site Investigation. Equipment: auger (hollow-stem), split-spoon sampler, Dutch cone Data sought and recorded. Types of Bearing. Friction piles In deposits with very deep bearing strata, perhaps minimal end-bearing

omer
Download Presentation

Pile Foundations Module #9

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Pile FoundationsModule #9 Prepared by Dr. Randy R. Rapp July 2005

  2. Site Investigation • Equipment: auger (hollow-stem), split-spoon sampler, Dutch cone • Data sought and recorded 2005, Randy R. Rapp

  3. Types of Bearing • Friction piles • In deposits with very deep bearing strata, perhaps minimal end-bearing • End-bearing piles • Compaction piles 2005, Randy R. Rapp

  4. Augering Caissons 2005, Randy R. Rapp

  5. Pile Types • Timber • Beware delivery and storage • Cast-in-place concrete • Cased • Pipe • Shell • Fluted • Uncased • “Wet” holes must be remediated 2005, Randy R. Rapp

  6. Pile Types (Cont’d) • Precast (typically prestressed) • Plant inspection may be required • Handling is critical: beware hard-to-see failures • Steel (H-pile) • Superior if splicing perhaps needed 2005, Randy R. Rapp

  7. Driving Piles • Match hammer, pile, cushions for efficiency • Impedance = ρ x c x A, potential capacity • Specified number of blows per inch driven indicates that capacity is achieved: • Wave equation analysis by instrumentation • Empirical formulas (dynamic behavior relates to static capacity?) 2005, Randy R. Rapp

  8. Driving Piles (Cont’d) • Count blows per foot, until design blow count approached • Then count blows per inch until specification achieved • Underdriving is costly, but overdriving might cause irreparable damage to any pile type—very costly • Pile heave: neighboring piles, frost 2005, Randy R. Rapp

  9. Driving H-Piles for Pile Cap 2005, Randy R. Rapp

  10. Hammer Types • Hammers • Drop • Air • Steam • Diesel • Vibratory • Leads • Fixed: A-frame • Hanging or swinging 2005, Randy R. Rapp

  11. Pile Load Tests • Load imparted to pile in gradual steps to twice design load, as settlement data recorded • Often, load removed in steps, too, to produce load-deflection curve, p. 228 • Behavior • Elastic deformation • Buckling • Puncture • Ensure multiple deflection references, in case one is lost 2005, Randy R. Rapp

  12. Pile Load Test 2005, Randy R. Rapp

  13. Inspector Duties • Review the hammer manual, if available • Be sure that the contractor is consistent: • Technique • Equipment settings • See pp. 241-44 2005, Randy R. Rapp

  14. Sheet Piling • Differences from bearing piles • Subsurface flow cutoff • Soil retention • Alignment critical: interlock usually desired • Anchored bulkheads • Soil “nails” 2005, Randy R. Rapp

  15. Driving Sheet Piles w/ Hydraulic Hammer 2005, Randy R. Rapp

More Related