HomeMy WebLinkAboutB15-0621 (2)VINCI ASSOCIATES
61ruclura/ Cn9ineers
March 19, 2015
Addy Electric
Subject: Review of minimum footing requirements
Project: (27) Module Photovoltaic Groundmount Installation (1 Array)
Bill & Pat Olsen
118 Ridgeview Lane, Oroville, CA 95966
V&A Project No.: 12-3457
The purpose of this report is to provide a site specific analysis of the minimum footing
requirements for the photovoltaic array groundtrac installation at 118 Ridgeview Lane
in Oroville, CA 95966.
Based upon our review of the 1 Photovoltaic Array, installed 3 modules high and 9
modules wide. The PV Array shall have a transverse spacing of approximately 6.58 feet
on center and a longitudinal spacing of 7.58 feet maximum. Based upon a wind speed
of 100 mph, Exposure C, it was determined that the minimum required footing depth is
32 inches minimum below grade for.a 12 inch diameter pier footing. The footing sizes are
based upon the worst case loading due to horizontal and vertical wind loading.
Refer to attached calculations and details for additional information. .
Our professional services have been performed using the degree of care and skill ordinarily
exercised under similar circu tances by reputable engineers practicing in this locality. No
other warranty, express e o Implied, is made as to the professional options included in this
report. We hope t 's ides you with the information you need at this time. Please call us
if you have any u ns regarding this report.
ES S/qy
Sincerely, a ?A
VINCI SSOCIATES
No. 54411 Z
Exp. 12/31/15 BUTTE
�*
J s .Vinci, S.E. COUNTY
TgTFOFF�` MAR 2 3 2015
ense No. S-4411
DEVELOPMENT
SERVICES
PERMIT # tet'
BUTTE COUNTY DEVELOPMENT SERVICES
REVIEWED FOR
CODE COMPLIANCE
175 E. WILBUR ROAD, STE 103 THOUSANDoDAKS, CA 91360
BY
P 805.496-2100 • .f 805.496-2442 •. a vinci@vincise.com 4 lcS �!
r'� �r
DATE: 3/19/2015 VINCI $ :_ASSOCIATES
SHEET:. Al
PROJECT: Bill & Pat Olsen 61rucfural Cngineers
JOB No.: 12-3457
'
118 Ridgeview Lane 175 E. WILBUR ROAD, STE 103 . THOUSAND OAKS, CA 91360
ENGR.:, JRV
Oroville; CA 95966 P 805.496.2100 • f805.496.'2442 • e Anci@VinciSE.com
CLIENT: Addy Electric
DESIGN DATA:
WIND DESIGN CRITERIA:
t
s BASIC WIND SPEED _
100
mph
(ASCE 740. Risk Category l per Table
1.5-1 & Figure 26.5-1C)
'
WIND EXPOSURE
C,
r
GROUND SNOW LOAD _
0 P'
psf
SOLAR MODULE ARRAY DATA
'
Sloped Dimension of Array" _
117:3
in ,
Angle of Array-. _
20,
degrees
Slope of Array: _
A.1 0 ...
, : 12 . .
No. of, Modules in Transverse Direction _
3• .
No. of Modules in Longitudinal Direction =
9
Total No. of Modules in Project _
27,
'
Transverse Post Spacing _
6.58
ft
Longitudinal, Post Spacing =
7.58
ft
Number of supports - Transverse Direction _
2
Diameter of Pier "Footing -
12
in
Number of Arrays
Array Uniform° Load
2.8.
psf
SOIL DESIGN CRITERIA (Based upon Chapter 18
of CBC)
"
Allowable Soil Bearing Pressure =
1500
psf
'
Allowable Soil Lateral Bearing =
200 '
pcf
Allowable ShaffSkin Friction / Cohesion =
130
pcf
AA-
PROJECT Bill &Pat Olsen ' ° _. ,
CLIENT:'1'18.Rldgeview Lane'Orovllle CA `"
V y PAGE
DESIGN BY
+"�
A2.`=-
�JRV,`
18.88
X95966 r.
-1.21 -1.46
-1.31 -1.60
1.51
JOB NO.. X15 -3457':_M. w . DATE : j03/19/15'.
REVIEW BY
t5 "_°.. a -
Wind Arial sis.for:Open Structure (Solar; Panels) Based on ASCE,7=2010
2013 CBC
F (kips) -1.01 -1.21 -1.09 -1.33 1.25 1.42 0.38
I�
INPUT DATA ,
Exposure category (13, C or D) = a,• r C`
Importance factor, 1.0 only, (Table 1.5-2) IW = 1.00
Basic wind speed (ASCE 7-10 26.5.1) V • _ • x'";100 mph
Topographic factor (26.8 8 Table 26.8-1) K = 1 �� "
K, '.,� _ 00:.• Flat p Jslope
Height of mean roof In , _ ' t 5 i. `= � ft �2 '
Roof slope 4:10 12
Roof length L`s10 l ft /
Roof horizontal projected width B = S''10:;'� ft
Effective area of component / cladding A . _ ?10 .aft2 8, lP,0,
DESIGN SUMMARY
1. Main Wind -Force Resisting System
Max horizontal force / base shear from roof = 0.86 kips
+ 0.09 kips (eave & columns increasing)
.�• E 0.95 kips f,
Max vertical download force + _ " 2.52 kips -
Max vertical uplift force = -2.33 kips
Max moment at centroid of base from roof = 7.51 ft -kips "
+ . 0.75 ft -kips (eave & columns increasing)
E 8.26 ft -kips '
2. Component and Cladding Elements ,
Max inward pressure = 63 psf~ -
' Max net outward pressure = 67 psf; , f
ANALYSIS
Velocity pressure
qh = 0.00256 Kh Kn Kd V2 = r - 18.50 psf
where: qh = velocity pressure at mean roof height, h. (Eq. 28.3-1 page 298 & Eq. 30,3-1 page 316)
Kh = velocity pressure exposure coefficient evaluated at height, h, (Tab. 28.3-1, pg 299) = 0.85
Kd = wind directionality factor. (Tab. 26.6-1, for building, page 250) = 0.85
In = height of mean roof �y = 5.00 ft
Main Wind -Force Resisting System (Sec. 27.4.3)
x
p=ghGCN
F=pAr r
where: G = gust effect factor. (Sec. 26.9) = 0.85
0 = roof angle - .' = 18.881 degree
< 45 deg. [Satisfactory]
Ar = roof actual area. = 54,8 ' .ft , windward
i
= 52.8 ft2, leeward
' ' CN = net force coefficients. (Fig. 27.4-4, page 267) • - r
Check Fig. 27.4-4 limitation , h / B = 0.50 within [0.25 , 1.0] [Satisfactory]
r
0
CASE
WIND TO BOTTOM, y = 00
CLEAR FLOW - . OBSTRUCTED 1
CNW CNL CNW CNL
WIND TO TOP, y = 180°
CLEAR FLOW OBSTRUCTED
CNW CNL CNW CNL
18.88
A
-1.21 -1.46
-1.31 -1.60
1.51
1.70
0.45
-1.05
P (psf) -19.03 -22.88 -20.55 -25.21 23.69 26.78 7.10
-16.48
F (kips) -1.01 -1.21 -1.09 -1.33 1.25 1.42 0.38
-0.87
B
-2.16 -0.16
-2.20 -0.76
2.01
0.65
1.25
0.14
P (psf) -33.94 -2.44 -34.64 -11.87 31.55 10.25 19.68
2.28
F (kips)
-1.79 -0,13-1
-1.83 -0.63
1.67
0.54
1.04
-0.12
DATE: 3/19/2015
V I N C I•&
ASSOCIATES SHEET: A3
PROJECT:- BIII & Pat Olsen
(51mclural Cn9meers
4 JOB NO.: • 09-3457
118 Ridgeview Lane
175 E. WILBUR ROAD, STE 103 • THOUSAND OAKS, CA ENGR.: JRV '
'
a Oroville, CA 95966
p805.496.2100 • (
805.496.2442 • e vinci@VinciSE.com
CLIENT: Addy Electric
-91360
V
' FOOTING DESIGN -
PV Sloped Dimension:
117.3 in
g „TYFICALtARRAY,+F fJ
PV Array Angle:
20 degrees
-
Post Spacing:
7.58 ft - •
'
No. of Supports:
2
.-' `
Footing Diameter (d):
12 'in
MAXIMUM VERTICAL FORCE: 2.52 k
/ (10.0 x 10.0 ) =
25.24 psf x 0.6 =; 15.14 psf
' MAXIMUM UPLIFT FORCE: 2.33 k
/ (10.0 x 10.0 ) = I .
23.26"psf ' x 0.6 = 13.96 psf
•
ASD Factor
GROUNDTRAC SYSTEM CAST INTO EARTH
'
Maximum Vertical Load: (Worst Case: DL+Wind)
P = 15.14 psf +
2.8 psf DL +
0 psf snow = 17.94 psf -
P = 17.94 psf x ( 110 "
/12"/ft) x ( 91.0 "
/12"/ft) = 1249
lbs for 2 Supports
' P = 625 lbs/footing
Try 12" diameter footing
Soil Bearing= 625
/ (p x 0.50). _
795.7 psf <<
1995 psf t
r
1500 psf x 1.33 (CBC Table 1806.2)
-Maximum Uplift Load:
Therefore O.K.
P = 13.96. psf - 2.8
psf DL =
11.16 psf
' P = 11.155 psf x ( 110"
/12"/ft) x ( 91.0 "
/12"/ft) _ 777`
lbs for 2 Supports
P = 388 lbs/footing
,
' Try 12" diameter x 32 "
footing '
' Allowable uplift =
Concrete DL + Soil Cohesion ( 130 psf x 1.33)
per CBC Table 1806.2
• [ (n x (d/2)2) x 150 pcf
x 2.7 ft ] +
[ (n x d) x 2.67 ft
x 172.9 psf] = 1764 lbs ,
Design Ratio =
( 1,764 lbs / 388 lbs)
_ 4.5
Therefore O.K.
V
DATE: 3/19/2015 VINCI & ASSOCIATES SHEET: A4 '
PROJECT: BIII & Pat Olsen JOB NO.: 09-3457 '
118 Ridgeview Lane 175 E. WILBUR ROAD, STE 103 • THOUSAND OAKS, CA 91360 ENGR.: JRV
Oroville, CA 95966 P805.496.2100 • f805.496.2442 • evinci@VinciSE.com
CLIENT: Addy Electric
DESIGN OF PIER FOOTING & POST CHECK '
Post Spacing: 7.58 ft
Number of Columns: 2
Horizontal Load: 9.5 psf
Exposed wind surface 3 ft
-DESIGN BASED UPON NON -CONSTRAINED CBC FORMULA:
(CBC Section 1807.3.2.1)
d = (A/2) (1 + ( 1 + (4.36h/A) )^.5))
D
h
d
GOVERNS >>>
DESIGN COLUMN
Mco1 =
Scot =
»»> USE:
P =
h =
S1 =
b =
A = (2.34"P)/(S1 "b)
90 lbs = 9.5 psf x 7.6 ft x 3 ft / 2 columns
5 ft (Average Height)
266 psf/ft x (d/3) (includes 1.33 increase for wind)
12 in (diameter or diagonal of square)
Try d =
(ft)
S1 @ (1/3)d
(psf)
A
Calc d
(ft)
1.67
1.92
2.17
2.42
148
170
192
215
1.422
1.237
1.094
0.981
3.58
3.29
3.05
2.85
77_77
2:67% ', a
t
h 23T
.
a r 0 889"'
..4,
` 2:69 = ' I
2.92
259
0.813
2.55
Ph = 450 ft -lbs
MC01 / Fb = 0.23 in Fb = 0.66 x 35,000 psi
ASTM A53, Gr B
1-1/2" Schedule 40 Pipe S = 0.31 in
with 12 inch diameter x 32 inch MIN. deep concrete footing.