HEWLETT PACKARD BUILDING 5 SEISMIC UPGRADE CORVALLIS OREGON

HEWLETT PACKARD BUILDING 5 SEISMIC UPGRADE CORVALLIS, OREGON, USA TOM A. ARMOUR, P. E. SESSION III STRUCTURAL SUPPORT & SEISMIC APPLICATIONS IWM 2002 MAY 29 – JUNE 1, 2002

PROJECT SYNOPSIS “Foundation Design & Construction” n Voluntary Seismic Upgrade Program n Braced Frame Retrofit Scheme n Foundation Support Required n Vibration and Noise Sensitivity n Access Issues n Strict Pile Deflection Criteria n Micropiles Most Feasible Option

SUBSURFACE PROFILE “Ground Conditions” Soft Clayey Silt (ML) Medium Dense Sands (SP) Very Dense Sandy Gravels (GP) 8 m 3 m

DESIGN SUMMARY “Foundation Support System” n Three Micropile Types n n n Seismic Design Loads n n n CASE 1 Type B micropiles 135 total micropiles Compression = 540 k. N – 720 k. N Tension = 450 k. N – 540 k. N Deflection Criteria n n Verif. = 6. 4 mm @ 900 k. N Test Load (1. 67 SDL) Proof = 3. 8 mm @ 810 k. N Test Load (1. 5 SDL) n New and Existing Pile Footings n 3 meters to Unlimited Headroom Access n Pile Load Test Program n n One Each Verification Test to 200% SDL on Non-Production Piles 5% Proof Tests on Production Piles

TYPICAL PILE DETAIL “H. P. Building 5” 10 m Casing 140 mm to 178 mm x 10. 5 mm to 16 mm wall casing Centralizer Med. Dense Sands Plunge Length Bond Zone 15 m Reinforcing Bar 50 mm & 63, 5 mm Neat Cement Grout

MICROPILE MATERIALS “H. P. Building 5” n Permanent Steel Pipe n n Steel Reinforcement n n n API 5 CT & ASTM A 252 550 MPa yield Flush joint threads ASTM A 615 Mechanical coupling Cement Grout n n n Neat cement – ASTM C 150 W/C ratio of 0. 45 27, 6 MPa (min)

MICROPILE CONSTRUCTION “ H. P. Building 5”

CONCLUSIONS “H. P. Building 5 Micropiles” n Another successful application of micropile use for seismic retrofit of sensitive buildings. n H. P. continuing to use micropiles on other building retrofits.