SI Field Report+2.7.2023_6.49.42_AM+33548711 of 5
LONGITUDE
ONE TWENTYO
ENGINEERING & DESIGN
Pile Review for Structural Compliance
Date: March 2"d, 2022
Project Name: Foundation Stabilization/Lift — Edmonds Project Number: S210720-4XR
Project Location: 814 Dayton St, Edmonds, WA 98020
Client's Name: Andi Holm, Project Coordinator — R&R Foundation Specialist, LLC
To Whom It May Concern:
The purpose of this letter is to confirm pile installation and capacity compliance with the structural re-
quirements specified in the L120 Structural Calculation Package and Structural Site Plan dated August 2,d
2021.
During the week of February 8th, 2022, five (5) helical piles were installed by R&R Foundation Specialists
(R&R) to stabilize areas of the single-family residence located at 814 Dayton St, Edmonds, WA 98020. To
the knowledge of L120, these piles were installed by R&R certified installers in accordance with the cited
structural package, ESR-3750. Please refer to the attached drive log and photographs provided by R&R.
The helical piles were installed with maximum pile spacing of 8'-0" on -center, the typical minimum required
vertical capacity as determined by L120 is shown in the table below. These demand requirements are as
determined and specified in L120's structural calculation package cited above.
PILE SPACING & LOAD REQUIREMENTS TABLE
MAX O.C. SPACING, ft
MIN VERTICAL CAPACITY, kips
PROOF TESTING LOAD, kips
PILE #
PILE TYPE
BTWN PILES
END OFFSET
ALLOWABLE LOADING
200% MIN VERTICAL CAPACITY
(MIN ULTIMATE CAPACITY)
LOCATION
i 2
HELICAL
8'-01.
PER PLAN
9.0 k/PILE
18.0 k/PILE
EXTERIOR
3-5
14.0 k/PILE
28.0 k/PILE
Pile capacities for the helical piles have been calculated using a Digga MM-10K drive head with a torque
correlation factor, Kt, of 9 as prescribed in ESR-3750. A chart showing the resulting capacities is attached
to this letter. Per the attached document, an Ideal Foundation Systems 2-7/8" diameter helical pile installed
to a minimum pressure of 1,000 psi results in a maximum allowable capacity of 15.7 kips including a safety
factor of 2.
2 of 5
The results are summarized below:
Helical Piles #1-#2:
Maximum Demand (allowable): 9.0 kips/pile
Available Capacity (allowable): 15.7 kips/pile
Helical Piles #3-#5:
Maximum Demand (allowable): 14.0 kips/pile
Available Capacity (allowable): 17.2 kips/pile
By inspection, the pile capacities of the installed piles exceed the maximum loading demand as determined
by L120's analysis. Therefore, the installed piles comply with the structural design/demand.
Please contact us if you have any questions.
Sincerely,
Jason Tien
L120 Engineering & Design (L120)
jtienAl120engineering. com
Mans R. Thurfjell, P.E.
L120 Engineering & Design (L120)
mthurfj ell@1120engineering.com
i F A 4 #
de IL
■ Fd
■ r
dL 'o }
+ A.1 } 1 t
3 of 5
Customer Address:
Helical Pier Data
Address: 814 Dayton St, Edmonds, WA, 98020
Drive head: 6k Lead:Tyson Bunce
0-5
5-10
10-15
15-20
20-25
25-30
30-35
3 5-40
40-45
45-50
50-55
55-60
Pier Spacing (ft)
0
T
1 2 3 4 5
500 400 500 600 600
1100 1000 800 700 800
1100 1100 1200
Final Depth 7' 8' 12' 12' 12'
6 7 8 9 10
4 of 5
MAX
Project Name: Foundation Stabilization/Lift - Edmonds Project Number: S210720-4XR
Project Location: 814 Dayton St, Edmonds, WA 98020
Client's Name: Andi Holm, Project Coordinator - R&R Foundation Specialist, LLC
Subject: 2 - 7/8" 0 Helical Pile - Compression Torque Chart - Digga MM-10K
ideal Foundation systems 2-718"0 Helical Pile 0.2034nch wall thickness) - Soil Capacity per ESR-3750
DIGGA 10K Drive Head
Pressure (psi)
Torque,?
(ft•lbsf
Torque Correlation Factor, K,
Compression (ft')
Ultimate Axial Compressive Capacity,
P. = K,1T (kips)
Allowable Axial Compressive
Capochy, P. =0.5'Pu(kips)
500
1,740
9
15.7
7.8
600
2,088
9
18.9
9A
700
2,436
9
21.9
11.0
goo
2,784
9
25.1
12.5
900
3,132
9
26.2
14.1
1000
3,490
9
31.3
15.7
1100
3,828
9
34.5
17.2
1200
4,176
9
37.6
19.9
1300
4,524
9
40.7
20.4
1400
4,872
9
43.9
21.9
1500
5,220
9
47.0
23.5
1600
5,568
9
50.1
25.1
1AM
5,916
9
53.2
26.6
18N
6,264
9
56.4
28.2
1900
6,612
9
59.5
79.8
2000
6,960
9
62.6
31.3
2100
7,308
9
65.9
32.9
2209
7,656
9
68.9
34.5
23N
81000
9
72.0
36.0
i.) DIGGA 10K Drive Head differential pressure display to torque output has been pulled from the attached conversion charts provided by DIGGA.
ii.j Per Table 5A of ESR-3750, the maximum installation torque rating of a 2-7/8"0 helical pile (0.203-inch wall thickness) is 8,300 ft'1bs. Per Ideal Manufacturing, Inc., the
maximum installation torque rating of a 2-718"0 helical pile (0.203-inch wall thickness) is 8,000 ft'ibs. Final installation torque shall not exceed the lesser of these limitingvaiues.
it Piles shall reach a torque that correlates with an allowable ca pa city that meets or exceeds the maximum allowable load demand as listed In the structural package, but sha ll not
exceed the maximum allowable ca pacity for any part of the pile assem hN.
iv.) Refer to ESR-3750 and Ideal Manufacturing, Inc. documents for additional information and requirements.
v.} Defin lions per ESR-3750:
T = Final Installation torque in ft'I bs; the last torque reading taken during pile installation, using, for example, the torque reading instruments connected
to the €nstallation equipment.
Kx = Torque correlation factor per ESR-3750
P„ = Ultimate axial compressive capacity (in kips) of helical pile
P, = Allowable axial compressive capacity (in kips} of helical pile
vi.) For torqu a readings between those listed, use the followi n g equation to determine the allowable capacity: Pa = (7* Kt)/2
vii.) 1 kip = 1,000 lbs
Digga - Speed & Torque Chart
Model Code: MM -10K
GF: 262
rpm vs Ipm
20 -
a 15
10
Q:
a 5
a
0
0 20 40 60 80
Flow rate (Ipm)
Max. Flow Ipm
70
Max. Speed (rpm)
16
Output Torque
Differential
Pressure
Display
Nm
Bar
2,360
34
2,832
41
3,303
48
3,775
55
4,247
62
4,719
69
5,191
76
5,663
83
6,135
90
6,607
7,079
97
103
7,551
110
8,023
117
8,495
124
8,967
131
9,438
138
9,910
145
10,382
152
10,854
159
11,326
166
11,798
172
12,270
179
12,742
186
13,214
193
13,686
200
14,158
207
<:7f)j77
rpm vs gpm
20
u 15
L
-a 10
CU
°1 5
A
0
0 5 10 15
Flow rate (gpm)
20
Max. Flow pm
18
Max. Speed (rpm)
16
Differential
Pressure
Display
Output Torque
PSI
Ibf-ft
500
1,740
600
2,088
700
2,437
800
2,785
900
3,133
1,000
3,481
1,100
3,829
1,200
4,177
1,300
4,525
1,400
4,873
5,221
1,500
1,600
5,569
1,700
5,917
1,800
6,265
1,900
6,613
2,000
6,961
2,100
7,310
2,200
7,658
2,300
8,006
2,400
8,354
2,500
8,702
2,600
9,050
2,700
9,398
2,800
9,746
2,900
10,094
3,000
10,442
* IMPORTANT: This chart is based on theoretical values and is provided as a guide only. Digga accepts no
responsibility complying with any installation requiring certain torques being reached. You will need to consult an
engineer.