HomeMy WebLinkAboutB12-0585 REV3 ENGINEER LETTER.pdf #CENTERLINE
SOLUTIONS
16360 Table Mountain Parkway, Golden, CO 80403
August 22, 2013
Mr. Warren Bloss
Crown Castle
RE: 810106
"Vail"
Retaining Wall—Electrical Vault
Dear Mr. Bloss:
Centerline Solutions designed a new retaining wall at the above referenced site. The wall
was designed using the site specific conditions and is detailed in the attached calculations
and drawings issued by this office.
Please contact us with any questions.
Sincerely,
r p R E G/ST,
rr
Khristopher Scott, PE 34610
Att: Calculations �� '• ••,. '`�,�
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AUG 1 Z 1013
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]RING WALT.SYSTEMS RETAINING WALL DESIGN N
KeyWall_2012 Version 3.7.2 Build 10
Project: Crowncastle- Vail Date: 811512013
Project No: 810106 Designer: KIS
Case: Case 1
Design Method:Rankine-w/Batter(modified soil interface)
Design Parameters --- -
Soil Parameters: deg
c psf y ncf
Reinforced Fill 28 0 120
Retained Zone 28 0 120
----------------
Foundation Soil 28 0 120 _.
Reinforced Fill Type: Sand, Silt or Clay �= 7oon
Unit Fill: Crushed Stone, 1 inch minus
Minimum Design Factors of Safety
sliding: 1.50 pullout: 1.50 uncertainties: 1.50
overturning: 2.00 shear: 1.50 connection: 1.50
bearing: 2.00 bending: 1.50
Design Preferences
Reinforcing Parameters: Mirafi AT Geogrids
Tult RFcr RFd RFid LTDS FS Tal Ci Cds
3XT 3500 1.58 1.10 1.05 1918 1.50 1279 0.80 0.80
Analysis: Case:Case 1
Electircal Vault Retaining Wall
Unit Type: Compac/120.00 pcf Wall Batter: 4.00 deg(Hinge Ht N/A)
Leveling Pad: Crushed Stone
Wall Ht: 6.00 ft embedment: 1.00 ft
BackSlope: 28.00 deg. slope, 20.00 ft long
Surcharge: LL:20 psf uniform surcharge DL: 0 psf uniform surcharge
Load Width: 100.00 ft Load Width: 100.00 ft
Results: Sliding Overturning Bearing Shear BeiMl Mg
Factors of Safety: 1.51 4.07 7.88 3.29 2.35
Calculated Bearing Pressure: 1078/1078 psf
Eccentricity at base: 0.14 ft
Reinforcing: (ft&lbs/ft)
Cale. Allow Ten Pk Conn Pullout
Laver Height Length Tension Reinf.Tyne Tal TO FS
3 4.67 7.0 204 3XT 1279 ok 449 ok 625 ok
2 2.67 7.0 480 3XT 1279 ok 597 ok 5.05 ok
1 0.67 7.0 589 3XT 1279 ok 745 ok 667 ok
Reinforcing Quantities (no waste included):
3XT 2.33 sy/ft
NOTE: THESE CALCULATIONS ARE FOR PRELIMINARY DESIGN ONLYAND SHOULD
NOT BE USED FOR CONSTRUCTION WITHOUT REVIEW B Y A QUALIFIED ENGINEER
Date 8/22/2013 Case I Page 1
DETAILED CALCULATIONS
Project: Crowncastle- Vail Date: 811512013
Project No: 810106 Designer:KIS
Case: Case I
Design Method:Rankine-w/Batter(modified soil interface)
Soil Parameters: deg c nsf y pcf
Reinforced Fill 28 0 120
Retained Zone 28 0 120
Foundation Soil 28 0 120
Leveling Pad: Crushed Stone
Modular Concrete Unit:Compac
Depth: 1.00 ft In-Place Wt: 120 pcf
Geometry
Internal Stability External Stability
(Broken geometry) (Broken geometry)
Height: 6.00 ft Height: 9.31 ft
BackSlope:
Angle:28.0 deg Angle:28.0 deg
Height: 10.63 ft Height: 7.32 ft
Batter: 4.00deg Batter: 4.00deg
Surcharge:
Dead Load: 0.00 psf Dead Load: 0.00 psf
Live Load:20.00 psf Live Load:20.00 psf
Base width: 7.0 ft
Earth Pressures:
sings+0)
ka =
s-
sin +,Y)si
sins a sin(a—S) 1+ — 8�
sin(a—(T)6.n(a+,3)
F R
Internal C rterrtrr
= 28 deg = 28 deg
a =94.00 deg a =94.00 deg
R =28.00 deg R =28.00 deg
5 =28.00 deg 5 =28.00 deg
H = 6.00 ft
ka =0.628 ka =0.550
Hinge Height: Hinge Ht=Not applicable
Date 8/2212013 Case 1 Page 2
Reinforcing Parameters:Miraft XT Geogrids
Tult RFcr RFd RFid LTDS FS Tal Ci Cds
3XT 3500 1.58 1.10 1.05 1918 1.50 1279 0.80 0.80
Connection Parameters:Mirafi XT Geogrids
Frictional I Break Pt Frictional 2
3XT Tcl=Ntan(42.80) +525 1100 Tcl=Ntan(11.10) +1328
Unit Shear Data
Shear =N tan(40.00)
Inter-Unit ShearShear=N tan(26 90) + 769.00
Calculated Reactions
For the "modified"design method, the back of the mass assumed to be vertical for calculation of resisting forces.
effective sliding length = 7.00 ft
q as
Pa:= 0.5H•(7'H•ka- 2c• a-) Pq:= q•H•ka € +x!14
Pal,:= Pa-cos(S) Pqh:= Pq•cos(S) Pas,Pasd
n
Pte,:= Pa•sin(S) Pqt,:= Pq•sin(S) � �,��� pa
r�
� A
pa
f
Reactions are:
Area Force Arm-x Arm-y Moment
Wl 720.00 [0.710] 3.000 511.04
W2 151.04 [1.280] 2.000 193.29
W3 4017.92 [4.210] 3.000 16914.55
W5 993.49 [5.140] 6989 510638
Pa_h 2527.26 7.000 [3.104] -7845.84
Pa v 1343.77 [7.000] 3.104 940638
Pgl_h 13.85 7.000 [4.657] -64.51
Pgl_v 7.37 [7.000] 4.657 51.56
Sum V= 7233.58 Sum Mr= 32183.20
Sum H= 2541.11 Sum Mo = -7910.35
Date 8/22/2013 Case I Page 3
Calculate Sliding at Base
For Sliding,Vertical Force=W1+W2+W3+W4+W5+W6+qd =7234
The resisting force within the rein.mass,Rf l =N tan(28)
=3846
The resisting force at the foundation,Rf 2 =N tan(28.00)
=3846
The driving forces,Df,are the sum of the external earth pressures:
Pa_h+Pgl_h+Pgd_h =2541
the Factor of Safety for Sliding is Rf 2/Df = 1.51
Calculate Overturning:
Overturning moment:Mo=Sum Mo =-7910
Resisting moment:Mr=Sum Mr =32183
Factor of Safety of Overturning: Mr/Mo =4.07
Date 8/22/2013 Case 1 Page 4
Calculate eccentricity at base: with Surcharge/without Surcharge
Sum Moments =24273 /24273
Sum Vertical=7234/7234
Base Length=7.00
e=0.144/0.144
Calculate Ultimate Bearing based on shear:
where:
Nq= 14.72
Nc=25.80
Ng= 16.72(ref.Vesic(1973, 1975)eqns)
Qult=8498 psf
Equivalent footing width,B'=L-2e=6.71 /6.71
Bearing pressure=sumV/B'= 1078 psf/ 1078 psf [bearing is greatest without liveload]
Factor of Safety for bearing=Qult/bearing=7.88
Calculate Tensions in Reinforcing:
The tensions in the reinforcing layer,and the assumed load at the connection,
is the vertical area supported by each respective layer, Sv.Column [7] is'2c sqrt(ka)'.
Table of Results ppf
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Layer Depth A hl ka/rho Pa Pas+Pasd c (5+6)cos(d)-7 Ti Tcl Tsc
3 1.33 1.17 0.706/34 231 0 0 204 204 449 N/A
2 3.33 3.33 0.679/36 543 0 0 480 480 597 N/A
1 5.33 5.17 0.646/38 667 0 0 589 589 745 N/A
Calculate sliding on the reinforcing:
The shear value is the lessor of base-shear or inter-unit shear.
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
Layer Depth zi N Li Cds i RF ka Pa Pas+Pasd DF FS
3 1.33 2395 600 0.80 850 1869 0.638 827 5 735 2.54
2 3.33 4122 600 0.80 972 2725 0.592 1570 11 1396 1.95
1 5.33 5906 600 0.80 1094 3606 0.558 2504 18 2226 1.62
Date 8/22/2013 Case 1 Page 5
Calculate pullout of each layer
The FoS(R*/S*)of pullout is calculated as the individual
layer pullout(Rf)divided by the tension(Df)in that layer.
The angle of the failure plane is: 31.00 degrees from vertical.
[1] [2] [3] [4] [5] [6] [7] [8]
Layer Depth zi Le Sumy Ci Poi Ti FS PO
3 1.33 3.52 1495 0.80 1272 204 6.25
2 3.33 4.58 2850 0.80 2425 480 5.05
1 5.33 5.65 4624 0.80 3933 589 667
Check Shear&Bending at each layer
Bending on the top layer is the FOS of overturning of the Units
(Most surcharge loads need to be moved back from the face)
[1] [2] [3] [4] [5] [61 [7] [8] [9]
Depth zi Si DM Pv RM FS b DS RS FS Sh
3 1.33 1.33 31 160 87 2.85 69 850 12.31
2 3.33 2.00 96 280 235 2.46 203 972 4.80
1 5.33 2.00 161 520 379 2.35 333 1094 3.29
Date 8/22/2013 Case 1 Page 6