2023-12-12 - Lee Residence (Janetta) - GEO459053OTTO ROSENAU & ASSOCIATES, INC.
Geotechnical Engineering, Construction Inspection & Materials Testing
GEOTECHNICAL INSPECTION REPORT
Report Number: 459053
Description: Grip-Tite Push Piers
Project: Lee Residence (Janetta) Permit Number: BLD2023-0794
Address: 9309 236th St SW, Edmonds Job Number: 23-0831
Client: Robbins & Co. Client Address: 818 SW 142nd Street, Burien
Inspector
and Date Remarks
Scott Hoobler, PE Arrived onsite as requested to observe the installation of 3-inch diameter, hydraulically driven, Grip-
12/12/2023 Tite piers driven into the subgrade using SPX Power Team hydraulic cylinder jack by Robbins and
Co for along the southwestern portion of the residence.
The successfully installed piers were installed into a suitable bearing stratum using the following
criteria specified by the project structural engineer.
• When an applied force equal to 40,000 pounds is achieved, or
• When an approximate lift of inch of the structure was observed.
The piers were installed in 3-foot sections. Additional pier sections were added using slip joint
connections. Listed below are the pier locations (see the attached figure), the final installation depth,
depth to bottom of the footing (measured from ground surface), design load of each pier, and the
final installation load. The final installation depth is measured from the bottom of the Grip-Tite
bracket.
Grip-Tite
Final
Depth to
Design
Final
Pier
Installation
Bottom of
Load
Installation
Notes
Location
Depth (feet-
Footing
(Pounds)
Load
inches)
(inches)
(Pounds)
1
3'-4"
24
6,180
19,240
1/2-inch lift of
foundation
2
3'-4"
17
3,600
14,430
1/2-inch lift of
foundation
3
3'-8"
17
3,520
24,050
1/4-inch lift of
foundation
4
4'
16
3,520
24,050
1/2-inch lift of
foundation
5
4'
15
3.520
24,050
1/2-inch lift of
foundation
6
3'
15
3,520
25,974
1/2-inch lift of
foundation
7
2'-10"
22
4,500
19,240
1/4-inch lift of
foundation
8
2'-10"
18
4,050
24,050
1/2-inch lift of
foundation
Copies to: Date: 2023.12.14
X Client X Contractor Anthony Coyne, P.E. 16:24:20-08'00'
Architect X Building Dept. Technical Responsibility:
X Engineer Anthony Coyne, P.E., Senior Engineer
This report applies only to the items tested or reported and is the exclusive property of Otto Rosenau & Associates, Inc. Reproduction of this report,
except in full, without written permission from our firm is strictly prohibited.
Page 1 of 3
6747 M.L. King Way S., Seattle, Washington 98118 - Phone (206) 725-4600 - Fax (206) 723-2221
Form No.: ADMIN-100-01 (Rev 01105)
OTTO ROSENAU & ASSOCIATES, INC.
Geotechnical Engineering, Construction Inspection & Materials Testing
Job Name: Lee Residence (Janetta)
Job No.: 23-0831
Report No.: 459053
A pier load testing was performed on each of the installed piers as described in Note 12 of the city -
approved project plan prepared by Hayman Engineering. The hydraulic pressure and equivalent
installation pressure was recorded at 18" intervals and the final installation depth as the pier was
installed. The applied load was fully removed following the completion of each pier load test.
Pier #/ Pier Pipe Depth
Below Bottom of Footing
Installation Pressure (psi)/
Installation Force (lbs.)
1 / 18"
0 psi / 0 lbs.
1 / 36"
600 psi / 5,772 lbs.
1 / 40"
2,000 psi / 19,240 lbs.
2 / 18"
500 psi / 4,810 lbs.
2 / 36"
500 psi / 4,810 lbs.
2 / 40"
1500 psi / 14,430 lbs.
3 / 18"
0 psi / 0 lbs.
3 / 36"
500 psi / 4,810 lbs.
3 / 44"
2,500 psi / 24,050 lbs.
4 / 18"
0 psi / 0 lbs.
4 / 36"
500 psi / 4,810 lbs.
4 / 48"
2,500 psi / 24,050 lbs.
5 / 18"
0 psi / 0 lbs.
5 / 36"
200 psi / 1,924 lbs.
5 / 48"
2,500 psi / 24,050 lbs.
6 / 18"
1,800 psi / 17,316 lbs.
6 / 36"
2,700 psi / 25,974 lbs.
7 / 18"
0 psi / 0 lbs.
7 / 32"
2,000 psi / 19,240 lbs.
8 / 18"
0 psi / 0 lbs.
8 / 34"
2.000 psi / 19,240 lbs.
An L-shaped Grip-Tite bracket was used to transfer load from the Grip-Tite pier to the existing
concrete foundation, except for pier location #2. At this location, a flat plate bracket had to be used
due to a support for the gas line being located at the same location as where Pier #2 was to be
located. The bracket was attached to the concrete foundation wall with a total of ten (10), DeWalt
screw -bolts (5 inches in length and 5/8 inches diameter) were installed into the concrete foundation
wall to hold the bracket in -place. Approval is required from the project engineer for the use of
the flat bracket at Pier Location #2 instead of the L-shaped bracket that is specified in the
City approved project plans.
Page 2 of 3
OTTO ROSENAU & ASSOCIATES, INC.
Geotechnical Engineering, Construction Inspection & Materials Testing
Job Name: Lee Residence (Janetta)
Job No.: 23-0831
Report No.: 459053
TYPICAL PIER
SECTION
❑ Grip-Tite Piers Installed Today
Page 3 of