Alternative Support Systems for Cantilever - National Transportation ...

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• Design loads for shear, flexure, and torsion (Vu, Tu, and Mu) • Superstructure interface base plate sized The designer should then use this information and their own design knowledge to design the following for the base connection: • Size the foundation interface base plate to match the superstructure interface base plate • Size the leveling bolts for design shear, flexure, and torsion • Ensure shear capacity of bolt holes exceeds design shear • Size the leveling nuts Embedded Pipe Design For the design of the embedded pipe, the designer will need the following information from the FDOT program or their own design: • Design loads for shear, flexure, and torsion (Vu, Tu, and Mu) • Superstructure monopole sized • Welded connection from superstructure monopole to superstructure interface base plate sized The designer should then use this information and their own design knowledge to design the following for the embedded pipe: • Size the cross section of the embedded pipe to have the same diameter and wall thickness as the superstructure monopole. The embedded pipe can be either a tapered section or an HSS pipe. • Size the welded connection from the embedded pipe to the foundation interface base plate to be the same as the welded connection from the superstructure monopole to the superstructure interface base plate. Embedded Pipe and Torsion Plates Design For the design of the torsion plates, the designer will need the following information from the FDOT program or their own design: • Design loads for shear, flexure, and torsion (Vu, Tu, and Mu) • Diameter and length of the circular pedestal portion of the concrete foundation • Specified concrete strength of the circular pedestal portion of the concrete foundation • Cross section geometry of the embedded pipe 174
The designer should then use this information and their own design knowledge to design the following for the embedded pipe and plate section (See Figure D-2): • Determine the number of torsion plates by engineering judgment (minimum of 4, Ntorsion plates) • Determine the length of torsion plates by engineering judgment (minimum of 6 inches) • Determine width and thickness of torsion plates by engineering judgment (minimum of 1 inch for each) • Determine the breakout edge distance, ca1 • Determine the angle available for each plate to breakout • Determine the angle required for group effect • Check group effect. If group effect present, reduce the number of plates or diameter of shaft until no group effect occurs. • Determine length of breakout • Determine breakout area of one plate • Determine breakout area of equivalent anchor bolt • Determine basic shear strength of one torsional plate • Determine the breakout strength of one torsional plate 175
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Report No. BDK75 977-04 Date: Augus
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Metric Conversion Table SYMBOL WHEN
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ALTERNATIVE SUPPORT SYSTEMS FOR CAN
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EXECUTIVE SUMMARY During the 2004 h
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CHAPTER TABLE OF CONTENTS 1 INTRODU
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Torsion Test Data .................
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LIST OF FIGURES Figure page Figure
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Figure 4-15. Arrangement of the LVD
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CHAPTER 1 INTRODUCTION This project
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CHAPTER 2 BACKGROUND The following
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information obtained in the late 19
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these problems. The concern with fa
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opposite side, see Figure 2-2 The s
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2.2.4 Helical Pipes This option wou
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2.3 Alternative Foundations from Ot
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Figure 2-10. Drilled concrete piles
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Figure 2-13. Grouted soil anchors G
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The pad and pier foundation, found
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comments and recommendations on pre
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CHAPTER 3 DESIGN IMPLICATIONS Based
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Figure 3-2. Differences between con
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2 [ ] 2 2 ( r ) + 3. 25 ( r ) − (
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eakout surface for a single plate,
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strength of a headed anchor in tens
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Figure 3-9. Schematic of anticipate
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Vbfp l e tfp bfp f’c ca1 = the ba
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3.2.2 Equivalent Side-Face Blowout
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computed. See Equation 3-14 below t
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One method to quantify the failure
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• An additional 12-4.5” long, 1
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Applied load Lever arm Figure 4-4.
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Figure 4-8. Isometric view of embed
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Flexural plate breakout area Torsio
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4.2.4 Annular Base Plate Design The
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torsional strength of the lever arm
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4.4 Concrete Block and Tie-Down Des
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Figure 4-13. Arrangement of the LVD
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4.7 Summary of Torsion and Flexure
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foundation displayed the predicted
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Figure 5-5. Specimen at failure 5.1
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Figure 5-7. Torsional moment and ro
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torsional 45 degree crack formation
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Figure 5-11. Widening of concrete b
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Failure cracks widen Bond loosens F
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Rear of shaft Figure 5-14. Load and
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testing, signifying that the predic
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provided in NCHRP Report 412 were i
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6.2.2 Tapered Embedded Steel Pipe a
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Figure 6-3. FDOT Design Standards I
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This option provides a possible alt
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6.2.5 Cast-in-Place Solid Concrete
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This option does have some disadvan
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Figure 6-9. Embedded steel pipe and
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However, the fillet welds are susce
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APPENDIX A TEST APPARATUS DRAWINGS
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Figure A-3. Dimensioned side elevat
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Figure A-5. Dimensioned drawings of
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Figure A-7. Dimensioned plan drawin
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Figure A-9. Dimensioned drawing of
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Figure A-11. Dimensioned view of em
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STIFFENER DESIGN Calculation of Cap
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L breakout Concrete Breakout Equiva
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Abrg L⋅b 7 in 2 := = .5 Nsb 200
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β 1 f c Calculations Using ACI Str
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Determine Flexural Capacity of Roun
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DEVELOPMENT LENGTHS OF FLEXURAL REI
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Short Pipe Design Flexural Strength
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Long Pipe Design Flexural Strength
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Superstructure Assembly Strength -
Page 139 and 140: Weld Design Tn_blowout Vweld := Tor
Page 141 and 142: Check_Bolt_Shear := "Sufficient Str
Page 143 and 144: Check Reinforcement No_Bars_Block_R
Page 145 and 146: Tie-Down Design Block Properties Wi
Page 147 and 148: Vmax Total Load that the Tie-down m
Page 149 and 150: λpf := .38⋅ λpw := 3.76⋅ E F
Page 151 and 152: Input and Properties Shaft Torsion
Page 153 and 154: ψcV := 1.4 ψecV := 1.0 ψedV := 1
Page 155 and 156: lbreakout := L + 2⋅1.5ca1 lbreako
Page 157 and 158: Rn_weld := Throat⋅FW Rn_weld 11.1
Page 159 and 160: ⎛ ⎜ ⎜⎜⎜⎜⎜⎜⎜ 9.250
Page 161 and 162: Flexural Capacity of T-Plates Using
Page 163 and 164: FAILURE EQUATIONS Torsion Threshold
Page 165 and 166: Required Length of Shaft Based on B
Page 167 and 168: Design Axial Strength ϕcomp := .90
Page 169 and 170: Design Axial Strength ϕcomp := .90
Page 171 and 172: Zp := ⎛ ⎜ ⎝ bp tp⋅ 2 ⎞
Page 173 and 174: Bolt Properties - D1" ASTM A325 Cen
Page 175 and 176: CONCRETE BLOCK Concrete Block Desig
Page 177 and 178: Check Shear Check_Shear_B := "Suffi
Page 179 and 180: 7'-4" 8" 5'-4" 8" 1'-3" Calculate s
Page 181 and 182: Required Capacity of the Channel As
Page 183 and 184: Check_Flange_Compact_Unit := "Compa
Page 185 and 186: Rear of Shaft Face of Shaft Figure
Page 187 and 188: Bolt slippage ends Predicted failur
Page 189: APPENDIX D DESIGN GUIDELINES For th
Page 193 and 194: • Determine the angle required fo
Page 195 and 196: Superstructure Base Connection Foun
Page 197 and 198: 1.5ca1 1.5ca1 Length of bearing are
Page 199 and 200: Vu = 9.04 kip T .u = 198.88 ft·kip
Page 201 and 202: Increase threaded rod diameter to 2
Page 203 and 204: Embedded Pipe and Torsion Plates De
Page 205 and 206: ⎝ ⎠ Check_Breakout_Torsion := "
Page 207 and 208: Lbreakout := tflex.plate + 2⋅1.5c
Page 209 and 210: ( ) .85 if fc < 4000psi β 1 f c .6
Page 211 and 212: REFERENCES 1. Cook, R.A., and Halco
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