Engineer Report1 of 6
LONGITUDE
ONE TWENTY°
ENGINEERING & DESIGN
Helical Pile Review for Structural Compliance
Date: April 4, 2023
Project Name: 22507 93'd PI W - Foundation Stabilization Effort L120 Project #S220513-1XR
Project Location: 22507 93'd PI W, Edmonds, WA 98020
Client's Name: Amanda Howe, Project Coordinator — R&R Foundation Specialist, LLC
To whom it may concern,
The purpose of this letter is to confirm helical pile installation and capacity compliance with the structural
requirements specified in the L120 Structural Calculation Package and Structural Site & Foundation Plan dated July
12, 2022.
On December 16, 2022, ten (10) helical piles were installed by R&R Foundation Specialists (R&R) to lift and stabilize
the residence located at 22507 93rd PI W. Piles were installed with a DIGGA 10k drive head to a maximum depth of
12ft. To the knowledge of L120, these piles were installed by R&R certified installers in accordance with the cited
structural package and ESR-3750. Please refer to the attached drive log provided by R&R.
With pile spacing at a maximum 5'-0" on -center, the minimum required vertical capacity as determined by L120
was allowable loadings of 7 kips per pile. These demand requirements are as determined and specified in L120's
structural calculation package cited above.
As required by the referenced structural package, proof testing was to be performed to 200 percent of the
specified design load. It is L120's understanding that the installers utilized the dead weight of the existing structure
to achieve the required reaction of a test pile.
Pile capacities for helical piles have been calculated utilizing the torque correlation factors provided in ESR-3750. A
torque/capacity chart detailing this calculation has been attached to this letter. Per the attached document, an
Ideal Foundation Systems 2-7/8in diameter 10k helical pile installed to minimum pressures of 1,000psi results in an
installation torque of 3,480 ft-lbs, and an allowable capacity of 15.7 kips including a safety factor of 2.
The results are summarized below:
Maximum Demand (allowable) = 7.0 kips/pile
Available Capacity (allowable) = 15.7 kips/pile
2 of 6
By inspection, the pile capacities of the installed helical piles exceed the maximum loading demand or reached
refusal as determined by 1-120's analysis. Therefore, the installed piles comply with the structural design/demand.
Please contact us if you have any questions.
Sincerely,
Peter Modica, P.E.
Project Engineer
L120 Engineering & Design (1-120)
pmodica@1120engineering.com
Mans R. Thurfjell, P.E
L120 Engineering & Design (L120)
mthurfiell@1120engineering.com
3of6
ELEVATION
MAP
- --North
-1 34
-2 f -2 1 /4
v,
19'
— ---- --
- - -
-2 1 /4
-2'-'
-2 1 /4
2
LOCATE PILE WITHIN -2 1 /2
cn
1' OF CORNER MAx
1
f
-21/4
-2
A
)-2
----
— _ -- =
- -
- -2/
f 4
4
�
I
t
-3/4 1
LOCATE PILE WITHIN
OD
OO
1' OF CORNER MAX
"'
-1 314
4
2 5
1/2
-4
- -
*
4' SEGEMENT OF
UO
j
L6x6x3/8 ANGLE IRON
p
-1/2 -1 1/4 30.8•'1/2
(2) PILES k5QC MAX -4
_1 =3 4 7'
6
Ua
w
7
0
11 1L8.5'
='
y LOCATE PILE WITHIN
4 1 /
1' OF CORNER MAX
-Angle Iron
8
-_ -¢ - Helical Pier
David Morrison Ideal Pier Data
93rd PI W Edmonds WA 98020
Pier Depth 1
1 111
2 3 4 5 6 7 8 9 10 1
111 11 11 11 11 111 1115 111 11
1
-1001
11 11 11
11
111
111
--
.1 .
-______-__
1
----__--__
4of6
PROJECT NO. SHEET NO.
PROJECT 22507 93rd PI W, Edmonds, WA
LONGITUDE SUBJECT
ONE TWENTYO
ENGINEERING & DESIGN
Foundation Stabilization/Jacking
DATE 07/12/22
Ideal Foundation Systems 2-7/8"0 Helical Pile (0.203-inch wall thickness) - Soil Capacity
per ESR-3750
DIGGA 10K Drive
Head Pressure
(psi)
Torque,
T
(ft*lbs)
Torque Correlation Factor,
K, fCompression)
(ft-')
Ultimate Axial Compressive Capacity,
P„ = Ki T
(kips)
Allowable Axial Compressive Capacity,
Pa = 0.5*P„
(kips)
500
1,740
9
15.7
7.8
600
2,088
9
18.8
9.4
700
2,436
9
21.9
11.0
800
2,784
9
25.1
12.5
900
3,132
9
28.2
14.1
1000
3,480
9
31.3
15.7
1100
3,828
9
34.5
17.2
1200
4,176
9
37.6
18.8
1300
4,524
9
40.7
20.4
1400
4,872
9
43.8
21.9
1500
5,220
9
47.0
23.5
1600
5,568
9
50.1
25.1
1700
5,916
9
53.2
26.6
1800
6,264
9
56.4
28.2
1900
6,612
9
59.5
29.8
2000
6,960
9
62.6
31.3
2100
7,308
9
65.8
32.9
2200
7,656
9
68.9
34.5
2300
8,004
9
72.0
36.0
2385
8,300
9
74.7
37.3
i.) DIGGA 10K Drive Head differential pressure display to torque output has been pulled from the attached conversion charts provided by DIGGA.
ii.) Per Table 5A of ESR-3750 and Ideal Manufacturing Inc., the maximum installation torque rating of a 2-7/8"0 helical pile (0.203-inch wall thickness) is 8,300
ft*lbs. Final installation torque shall not exceed this value.
iii.) Piles shall reach a torque that correlates with an allowable capacity that meets or exceeds the maximum allowable load demand as listed in the structural
package, but shall not exceed the maximum allowable capacity for any part of the pile assembly.
iv.) Refer to ESR-3750 and Ideal Manufacturing, Inc. documents for additional information and requirements.
v.) Definitions per ESR-3750:
T= Final Installation torque in ft*lbs; the last torque reading taken during pile installation, using, for example, the torque reading
instruments connected to the installation equipment.
K, = Torque correlation factor per ESR-3750
P„ = Ultimate axial compressive capacity (in kips) of helical pile
Pa = Allowable axial compressive capacity (in kips) of helical pile
vi.) For torque readings between those listed, use the following equation to determine the allowable capacity:Pa = (T*IQ/2
vii.) 1 kip = 1,000lbs
viii.) Per Note 3 of Ideal Group Dwg No.: 278TFG dated 4/23/20, the ultimate structural capacity for the 2 718" TRU-FORCE Underpinning Bracket is limited to
60 kips.
* See Note viii.
* See Note h.
L120 ENGINEERING & DESIGN
MM-10K MOUNTS
AVAILABLE TO SUIT
STAND ON MINI
MACHINES AND MINI
EXCAVATORS UP TO 3.5T
Lightweight hand-held screw anchor drive for the installation of screw
piles in confined or low access sites such as crawl spaces. This unit can be
powered by portable hydraulic power packs.
FEATURES
• Compact high torque Digga manufactured gearbox
• Lightweight and compact for ease of movement in confined spaces
• Fitted with a high efficiency Eaton/Digga geroler hydraulic motor
• Motor mounted pressure relief valve fitted standard (HH-6K)
• Over 34 years design and manufacturing experience
• 1yr gearbox and 1yr motor warranty
SPECIFICATIONS
MODEL
HH-6K
MM-10K
Theoretical Torque (ft-Ibs)
6,528 @ 2,100psi
10,478 @ 3,000psi
Expected Torque (ft-Ibs)
4,765 @ 2,100psi
8,040 @ 3,000psi
(73% efficiency)
(77 /o efficiency)
Max Pressure
2,100psi @ I Igpm
3,000psi @ 18.5gpm
Max Flow
15gpm @ 2300psi
18.5gpm @ 3000psi
Max Horse Power
20
33
Pressure Relief Valve
Included
NA
Standard Output Shaft
2" Hex
2.5" Hex -Short
Weight (Ibs)
90
138
Overall Length (in)
20"
24.1"
Diameter (in)
9.5"
11.4"
HH-6K Hand-held unit is not suitable for machine mounting. Warranty void if used on machines.
OUTPUT SPEED & TORQUE
l.i;ID:i
OUTPUT SPEED
GPM RPM
7 7
8 8
9 9
10 10
11 11
12 12
13 13
14 14
15 15
OUTPUTTORQUE
PSI FT-LBS
500 1,554
750 2,331
1,000 3,108
1,250 3,886
1,500 4,663
1,750 5,440
2,000 6,217
2,100 6,528
MM-10K
OUTPUT SPEED
GPM RPM
7 6
8 7
9 8
10 9
11 10
12 11
13 11
14 12
15 13
16 14
17 15
18 16
OUTPUTTORQUE
PSI FT-LBS
500 1,746
1,000 3,493
1,500 5,239
2,000 6,985
2,500 8,732
3,000 10,478
Output speed and torque specifications are THEORETICAL. Speed and torque output are dependent on the overall system efficiencies associated with the prime movers hydraulic system.
This document should be used for information and comparative purposes only. When determining criteria, & application specific information is required, please contact DIGGA.
--Y+
6'6f 6
Digga - Speed & Torque Chart
Model Code: MM -10K
GF: 262
rpm vs Ipm
20
L 15 ode
D 10 -
d
a, 5 -
a
N
0
0 20 40 60 80
Flow rate (Ipm)
Max. Flow I m 70
Max. Speed (rpm)l 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
rpm vs gpm
20
n. 15
10
d
01 5
a
N
0
0 5 10 15 20
Flow rate (gpm)
Max. Flow m 18
Max. Speed (rorn)l 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.