1. Construction of Bents Joshua Black and Sharon Wood Department of Civil, Architectural and Environmental Engineering University of Texas at Austin

2. Overview Site layout Construction Material properties

3. Site Layout Map of Austin Plan of site Photograph of site Location of shafts and bents

4. Fitzpatrick Ranch

5. Fence Borehole S1 Depth: 14.5 ft SPT Borehole D1 Depth: 36 ft Borehole S2 Depth: 9.5 ft SPT Borehole D2 Depth: 36.5 ft Test Site: 60 x 50 ft Test Site Magnetic North

6. Fitzpatrick Ranch View from South View from North

7. Fence Magnetic North Bent 1 Bent 2 40 ft 15 ft 1W1E 2N 2S Test Site Project North

8. Bent 1 Bent 2 Shaft 1WShaft 1E Shaft 2N Shaft 2S

9. Construction Shaft/column reinforcement Drilled shafts Formwork Concrete placement in shaft/column Construction of bent caps

10. Shaft/column reinforcement Reinforcing cages were fabricated in Ferguson Structural Engineering Laboratory Strain gages and geophones were attached to cages Complete cages were transported to site

11. Shaft/Column Reinforcement 16 - #3 Bars 12 in. ¾ in. Cover W2.9 Spiral 1¼ in. pitch Clear spacing between bars = 3.3 in. Column diameter

14. Drilled Shafts Commercial drill rig was used Shafts were larger in diameter than anticipated ―Desired diameter = 12 in. ―Actual diameter ≈ 18 in. Caving of soil was observed in all shafts

19. Shaft 2N

20. Shaft 2S

26. Formwork 12-in. Sonotubes were used above grade Sonotubes extended approximately 7 in. below grade Cages were centered within shafts Formwork was supported at grade and near top. Cables for strain gages and geophones were positioned outside the formwork before placing the concrete

27. Formwork at Grade AA Plywood Base Plate 2x4 Collar Cardboard Tube Form 2x4 Collar Plywood Base Plate Cardboard Tube Form Approx. 7 in. Edge of Hole Concrete (Reinforcing cage is not shown) Section A-A Plan View

29. Shaft 2N

30. Bent 2 2N 2S

31. Bent 1 1E 1W

32. Concrete Placement in Shafts Ready-mix concrete was placed using a concrete pump Concrete vibrator was used at grade and at the top of the shafts

36. Bent Caps Reinforcing cages for bent caps were tied on site Concrete was placed using a front-end loader Threaded rods were cast in the bent caps to apply lateral forces during static tests Adapter plate designed to accommodate the shaker from Thumper was embedded in fresh concrete

47. Material Properties Concrete (Shafts, Columns, and Beam) ― = 7200 psi ― = 4600 ksi Steel (Shafts and Columns) ― = 60.8 ksi ― = 102 ksi Soil ―Nonplastic silt ―Documented in site characterization report (Kurtuluş, Lee, and Stokoe, 2005)

48. Josh Black, MS 2005