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Geometry of Bents and Instrumentation for Dynamic Tests. Joshua Black and Sharon Wood Department of Civil, Architectural and Environmental Engineering University of Texas at Austin. Overview. Bent Geometry Instrumentation for Dynamic Tests. Bent Geometry. Elevations of Bent 1
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Geometry of Bentsand Instrumentationfor Dynamic Tests Joshua Black and Sharon Wood Department of Civil, Architectural and Environmental Engineering University of Texas at Austin
Overview • Bent Geometry • Instrumentation for Dynamic Tests
Bent Geometry • Elevations of Bent 1 • Elevations of Bent 2 • Coordinate systems • Terminology
Bent 1 Bent 2 Shaft 1W Shaft 1E Shaft 2S Shaft 2N
Bent 1 24" 10'-0" 18" 12" 12" 6'-0" ~18" ~18" 12'-0" 6'-3" (a) Transverse Elevation (b) Longitudinal Elevation
Bent 2 24" 10'-0" 18" 3'-0" 12" 12" ~18" ~18" 12'-0" 6'-3" (a) Transverse Elevation (b) Longitudinal Elevation
Coordinate System – Bent 1 Project North 1W 1E x z y z = 0 is at ground level
Coordinate System – Bent 2 Project North x 2N z y 2S z = 0 is at ground level
Terminology Longitudinal Response of Bridge Transverse Response of Bridge
Instrumentation • Accelerometers and geophones • Strain gages
Bent 1 Geo1E Geo1W Acc1W Acc1E 3D Accelerometer 3D Geophone GeoG1 Geophone 15 Geophone 23 Geophone 14 Geophone 24 Shaft 1W Shaft 1E
Bent 2 Geo2S Geo2N Acc2N Acc2S 3D Accelerometer GeoG2 3D Geophone Geophone 17 Geophone 27 Geophone 26 Geophone 18 Shaft 2N Shaft 2S
Local axes of accelerometers are shown. Data are presented in terms of the global coordinates in data files. z y 1W 1E x Acc1E x x z y z y z z Acc1W y x y Orientation of Accelerometers Acc2N x Project North 2N 2S x Acc2S y z
3D Geophones (Bent 1) Geo1W Geo1E
3D Geophones (Bent 2) Geo2N Geo2S
T 2N L Geo2N 1W 1E x L L x T T z z y Geo1W Geo1E y 2S L Geo2S T Orientation of Geophones Project North • Local axes of geophones are shown. • Data are expressed in terms of the global coordinates in data files.
Strain Gages • Strain gages were attached to the surface of the longitudinal reinforcing bars. • Each strain gage is located using three parameters: • Column • Orientation of longitudinal reinforcement • Vertical distance from grade • Example: • Strain gage 2S:225:024 • Column 2S, Bar orientation 225°, 24 in. below grade
270 315 225 0 x 180 z 135 45 90 y Orientation of Reinforcement • Coordinate system used to define orientation of reinforcement is same as coordinate system used to define configuration of bent. • Each pair of longitudinal bars is defined byangle θ. x 0 45 315 z 90 y 270 135 225 180 Bent 1 Bent 2
Strain Gage Locations – Bent 1 * Distances are measured along the z axis. Positivevalues correspond to locations below grade. Negative values correspondto locations above grade.
Strain Gage Locations – Bent 2 * Distances are measured along the z axis. Positivevalues correspond to locations below grade. Negative values correspondto locations above grade.