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PRECAST CONCRETE COUPLED WALL SYSTEMS. Brad Weldon Yahya C. (Gino) Kurama University of Notre Dame PCI Daniel P. Jenny Research Fellowship. PCI Committee Days April 24, 2004. REINFORCED CONCRETE COUPLED WALLS. wall beam wall. Paulay and Priestley 1991.
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PRECAST CONCRETE COUPLED WALL SYSTEMS Brad Weldon Yahya C. (Gino) Kurama University of Notre Dame PCI Daniel P. Jenny Research Fellowship PCI Committee Days April 24, 2004
REINFORCED CONCRETE COUPLED WALLS wall beam wall Paulay and Priestley 1991 mechanisms of shear resistance in reinforced concrete coupling beams Coupling Degree TL CD Mw1+Mw2+TL Mw1 Mw2 L T C=T
PRECAST CONCRETE COUPLING BEAMS concrete wall confinement connection region PT anchor wall region angle precast beam beam PT tendon confined concrete PT duct PT tendon beam
DEFORMED SHAPE AND COUPLING FORCES contact region gap opening Vcoupling reference line P z db P lb beam Vcoupling Pz @ V l coupling b
OBJECTIVES • Develop new system based on experimental and analytical studies • Develop seismic design/analysis guidelines and tools, and recommendations for application
OUTLINE • Steel Coupling Beams • Experimental program • Analytical model and verification • Precast Coupling Beams • Advantages • Parametric studies (DRAIN-2DX) • Design approach
STEEL BEAM TESTS • Eleven half-scale coupled wall subassemblages (angle, beam, post-tensioning properties) Elevation View (half-scale) test wall region L4x8x5/8 and reaction fixture • Objectives • Investigate M-q behavior • Verify analy. models • Verify design tools and procedures load block W10x68 PT strand strong floor lw=1.5 m lb=1.5 m (5 ft) lw=1.5 m ap=140 mm2 (0.217 in2) fpi=0.6fpu
TEST SET-UP actuators loading block wall region beam reaction block
ANGLE FRACTURE Beam rotation = 9% Test 5 Test 5 Test 2
CYCLIC BEHAVIOR OF STEEL COUPLING BEAM applied shear force, kips (kN) 60 (267) measured 0 (-267) -60 -10 10 0 beam chord rotation, %
VERIFICATION OF MODEL applied shear force, kips (kN) 60 (267) measured predicted 0 (-267) -60 -10 10 0 beam chord rotation, %
POST-TENSIONED COUPLED WALLS • Unbonded post-tensioning is a promising and feasible method to couple concrete walls (up to 60-65 percent coupling) • Large self-centering, considerable energy dissipation • Large deformations with little damage • The analytical models and design tools/procedures work well • Shift focus towards precast beams
PRECAST ADVANTAGES • Simpler beam-to-wall joints • Central location of PT strands • Fire and environmental protection • Higher friction resistance against shear sliding • Favorable tolerances for construction • Cost-efficient
PARAMETRIC STUDY DRAIN-2DX(Half-Scale Subassemblages) • Varied Parameters: • beam depth • amount of PT • angle size • gage length • aspect ratio
TEST SPECIMEN CROSS-SECTIONS(Half-Scale) L8x4x1/2 L8x4x1/2 14” 14” 7” 7” L8x4x1/2 L8x4x5/8 14” 18” 7” 7”
DRAIN-2DX SPECIMEN BEHAVIOR D = 14” L8x4x1/2 PT = 3 D = 14” L8x4x1/2 PT = 4 60 60 (267) (267) applied shear force, kips (kN) applied shear force, kips (kN) (-267) (-267) -60 -60 0 0 -8.0 8.0 -8.0 8.0 beam chord rotation, (%) beam chord rotation, (%) D = 18” L8x4x5/8 PT = 4 D = 14” L8x4x5/8 PT = 4 80 80 (356) (356) applied shear force, kips (kN) applied shear force, kips (kN) 0 (-356) (-356) -80 -80 0 0 -8.0 8.0 -8.0 8.0 beam chord rotation, (%) beam chord rotation, (%)
DRAIN-2DX VERSUS ABAQUS beam shear, kips (kN) contact depth/depth 1 300 ABAQUS (1335) DRAIN-2DX ABAQUS DRAIN-2DX 0 7 0 7 beam rotation, % beam rotation, %
BEAM DESIGN longitudinal reinforcement thru ducts for angle connection PT duct transverse reinforcement confined concrete
BEAM DESIGN transverse reinforcement confined concrete PT duct beam end view beam side view longitudinal reinforcement
BEAM TO WALL CONNECTION wire mesh L8x4x1/2 thru bolt grout PT strand confined concrete
CURRENT STATUS • Finalizing design • Laboratory set-up • Begin testing this summer
ACKNOWLEDGMENTS • Precast/Prestressed Concrete Institute • University of Notre Dame • Industry Participants • Cary Kopczynski & Company • StresCore Inc. • Dywidag Systems International, U.S.A, Inc. • Insteel Wire Products • Dayton/Richmond Concrete Accessories