High Strain Dynamic Testing of Large Diameter, High Capacity, Inclined Cast In-situ Piles-PPT Presentation

PPT Presentation

Pdf Summary

The I-395/SR 836/I-95 Design-Build Project in Miami, Florida, includes the Signature Bridge and extensive cast-in-place foundation work. The project used 2,230 auger-cast-in-place piles, both vertical and inclined, with diameters of 30 or 36 inches and lengths of 80 to 140 feet. On the SR 836 Bridge 101 segment alone, 84 of 415 30-inch piles were battered at a 1:8 slope; factored design loads ranged from 486 to 1,426 kips.<br /><br />Applied Foundation Testing conducted high-strain dynamic drop-hammer tests to proof-load piles to their factored design loads. Three hammer systems were used, including a 42-kip hydraulic tilt-and-lift ram for inclined piles. Preparation included forming a level, perpendicular pile top with high-strength grout and securely anchoring the force transducer. Testing followed ASTM D4945, with force and acceleration data collected using a Pile Driving Analyzer. CAPWAP signal matching was then used to estimate static pile capacity.<br /><br />Comparisons of vertical and battered piles found consistent data quality. The energy-transfer ratio appeared unaffected by batter angle at drop heights up to 3.5 feet. The testing approach emphasized a heavy ram, relatively low drop height, and minimizing friction during the drop. The program was intended to verify piles against design loads, not to establish new design values through full-scale load testing.

Keywords

I-395

SR 836

I-95

Miami Florida

Signature Bridge

auger-cast-in-place piles

dynamic pile testing

ASTM D4945

CAPWAP

battered piles