Alternative Support Systems for Cantilever - National Transportation ...

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Figure 2-11. Typical transmission line structures compared to a cantilever sign structure Prestressed soil anchor Figure 2-12. Prestressed soil anchor Lattice Tower Single Pole Structure H-Structure 16 Cantilever Sign Pressure Bulb Unbonded Tendon
Figure 2-13. Grouted soil anchors Grouted soil anchors are designed to transfer uplift or tensile loads from the superstructure directly to the soil (9). They do this through frictional resistance between the grout and soil, as well as through the end bearing strength from the increased diameter at the end of the anchor (9). However, the anchors do not provide much torsional resistance because of their smooth geometry. Despite the fact that these are viable alternatives in the field of transmission line foundations, these are generally not preferable options for sign and signal foundation systems. The fact that sign and signal installations are sequenced at the end of highway construction make piles and anchors undesirable options. By the time the contractor is installing signs and signals, most of the large pile-driving equipment has been moved off the construction site and would create additional expense for the contractor. Time and expense are also reasons why these options are not preferred. Prestressed anchors and grouted soil anchors require geotechnical expertise as well as significant geotechnical analysis of the area and would need to be designed for individual projects which can be more costly. It would be difficult to produce a standard for these options. Friction Anchor 17 Multi-Belled Anchor Belled Anchor
Page 1 and 2: Report No. BDK75 977-04 Date: Augus
Page 3 and 4: Metric Conversion Table SYMBOL WHEN
Page 5 and 6: ALTERNATIVE SUPPORT SYSTEMS FOR CAN
Page 7 and 8: EXECUTIVE SUMMARY During the 2004 h
Page 9 and 10: CHAPTER TABLE OF CONTENTS 1 INTRODU
Page 11 and 12: Torsion Test Data .................
Page 13 and 14: LIST OF FIGURES Figure page Figure
Page 15 and 16: Figure 4-15. Arrangement of the LVD
Page 17 and 18: CHAPTER 1 INTRODUCTION This project
Page 19 and 20: CHAPTER 2 BACKGROUND The following
Page 21 and 22: information obtained in the late 19
Page 23 and 24: these problems. The concern with fa
Page 25 and 26: opposite side, see Figure 2-2 The s
Page 27 and 28: 2.2.4 Helical Pipes This option wou
Page 29 and 30: 2.3 Alternative Foundations from Ot
Page 31: Figure 2-10. Drilled concrete piles
Page 35 and 36: The pad and pier foundation, found
Page 37 and 38: comments and recommendations on pre
Page 39 and 40: CHAPTER 3 DESIGN IMPLICATIONS Based
Page 41 and 42: Figure 3-2. Differences between con
Page 43 and 44: 2 [ ] 2 2 ( r ) + 3. 25 ( r ) − (
Page 45 and 46: eakout surface for a single plate,
Page 47 and 48: strength of a headed anchor in tens
Page 49 and 50: Figure 3-9. Schematic of anticipate
Page 51 and 52: Vbfp l e tfp bfp f’c ca1 = the ba
Page 53 and 54: 3.2.2 Equivalent Side-Face Blowout
Page 55 and 56: computed. See Equation 3-14 below t
Page 57 and 58: One method to quantify the failure
Page 59 and 60: • An additional 12-4.5” long, 1
Page 61 and 62: Applied load Lever arm Figure 4-4.
Page 63 and 64: Figure 4-8. Isometric view of embed
Page 65 and 66: Flexural plate breakout area Torsio
Page 67 and 68: 4.2.4 Annular Base Plate Design The
Page 69 and 70: torsional strength of the lever arm
Page 71 and 72: 4.4 Concrete Block and Tie-Down Des
Page 73 and 74: Figure 4-13. Arrangement of the LVD
Page 75 and 76: 4.7 Summary of Torsion and Flexure
Page 77 and 78: foundation displayed the predicted
Page 79 and 80: Figure 5-5. Specimen at failure 5.1
Page 81 and 82: Figure 5-7. Torsional moment and ro
Page 83 and 84:
torsional 45 degree crack formation
Page 85 and 86:
Figure 5-11. Widening of concrete b
Page 87 and 88:
Failure cracks widen Bond loosens F
Page 89 and 90:
Rear of shaft Figure 5-14. Load and
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testing, signifying that the predic
Page 93 and 94:
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
Page 99 and 100:
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
Page 111 and 112:
Figure A-3. Dimensioned side elevat
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Figure A-5. Dimensioned drawings of
Page 115 and 116:
Figure A-7. Dimensioned plan drawin
Page 117 and 118:
Figure A-9. Dimensioned drawing of
Page 119 and 120:
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
Page 127 and 128:
β 1 f c Calculations Using ACI Str
Page 129 and 130:
Determine Flexural Capacity of Roun
Page 131 and 132:
DEVELOPMENT LENGTHS OF FLEXURAL REI
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Short Pipe Design Flexural Strength
Page 135 and 136:
Long Pipe Design Flexural Strength
Page 137 and 138:
Superstructure Assembly Strength -
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Weld Design Tn_blowout Vweld := Tor
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Check_Bolt_Shear := "Sufficient Str
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Check Reinforcement No_Bars_Block_R
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Tie-Down Design Block Properties Wi
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Vmax Total Load that the Tie-down m
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λpf := .38⋅ λpw := 3.76⋅ E F
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Input and Properties Shaft Torsion
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ψcV := 1.4 ψecV := 1.0 ψedV := 1
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lbreakout := L + 2⋅1.5ca1 lbreako
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Rn_weld := Throat⋅FW Rn_weld 11.1
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⎛ ⎜ ⎜⎜⎜⎜⎜⎜⎜ 9.250
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Flexural Capacity of T-Plates Using
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FAILURE EQUATIONS Torsion Threshold
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Required Length of Shaft Based on B
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Design Axial Strength ϕcomp := .90
Page 169 and 170:
Design Axial Strength ϕcomp := .90
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Zp := ⎛ ⎜ ⎝ bp tp⋅ 2 ⎞
Page 173 and 174:
Bolt Properties - D1" ASTM A325 Cen
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CONCRETE BLOCK Concrete Block Desig
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Check Shear Check_Shear_B := "Suffi
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7'-4" 8" 5'-4" 8" 1'-3" Calculate s
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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
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Bolt slippage ends Predicted failur
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APPENDIX D DESIGN GUIDELINES For th
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The designer should then use this i
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• Determine the angle required fo
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Superstructure Base Connection Foun
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1.5ca1 1.5ca1 Length of bearing are
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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
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⎝ ⎠ 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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