18-104600CITY OF
.. Federal Way
Centered on Opportunity
October 15, 2018
Your Girl Friday
Attn: Teresa Fortino
4001 NW 35`h Avenue
Gig Harbor, WA 98335
RE. Multicare Off -Campus Emergency Center; Folder # 18-104600-000-00-SM;
Response to Request for Soil Nails within Right -of -Way
Dear Ms. Fortino:
CITY HALL
33325 8th Avenue South
Federal Way, WA 98003-6325
(253) 835-7000
www.cityoffederalway.com
Jim Ferrell, Mayor
The City of Federal Way has reviewed your request to allow Soil Nail within the right-of-way dated
September 27, 2018. After evaluating the existing conditions along 16`h Avenue S, review of the Federal Way
Revised Code (FWRC) provisions (Section 19.135.040 thru 19.135.070) and the direction provided by the City
Council, the Public Works Department provides the following response to your request:
Request to allow soil nails within the 16th Avenue S. right-of-way
Staff requested right-of-way sections along with an estimate of the total number of soil nails proposed to be
installed along 10 Avenue S. GeoEngineers estimated that between 40 and 60 soil nail would intrude into
the right-of-way. Section A -A indicated that at the edge of the right of --way they highest soil nail would be
approximately 15-feet below ground surface.
Staff also reviewed both previous requests for soil nails which included the Wal-Mart on 161h Avenue and
Sound Transit's Federal Way Light Rail Extension.
The Public Works Department hereby denies this request to allow soil nails within a City right-of-way.
The conditions of this decision will be applicable for one year from the date of the letter. If you have any questions
or concerns, please contact Cole Elliott, P.E., Development Services Manager, at (253) 835-2730.
Sincerely,
EJ Walsh, P.E.
Public Works Director
CE:mt
oc: Brett Larabee, P.E., GeoEngineers, Inc., 1101 Fawcett Ave #200, Tacoma, WA 98402
Costa Philippides P.E., Barghausen Consulting Engineers, 18215 72Id Avenue S, Kent, WA 98032
Project File (ce)
Day File
\\cfwfile 1 \applications\csdc\prod\docs\save\ 154112_78332_05133014.doc
CITY OF
Federal Way
PUBLIC WORKS
DEPARTMENT
STREET MODIFICATION REQUEST / ACTION
Project Name MultiCare Off -Campus Emergency Clinic
Permit # 18-104600-SM
Location 29805 Pacific Highway S
Request
The Applicant proposes to construct a 9,800 square feet emergency clinic on a 1.7 acre of land.
Part of the design includes a retaining wall along the western portion of the land. The retaining
wall will vary in height from 1-foot to over 20-feet. The current design proposes to use a
retaining wall design which requires soil nails.
Staff Analysis
To understand the potential impact of the request, staff requested sections to show some of
the proposed soil nails, the distance into the existing/future right-of-way and an estimate of
the total number of soil nails which may be installed into the right-of-way.
If allow, GeoResources estimate between 40 and 60 soil nails will extend into the City's
right-of-way. Section A -A shows the most intrusive situation where a group of three soil
nails extend approximately 3-feet into the right-of-way with the closest to ground level
located approximately 15-feet down.
A review of previous requests to use soil nails within the right-of-way indicates that all
previous requests (Sound Transit and Marketplace Center) have been denied.
Requirements / Conditions of Approval
Development Services staff recommend that Public Works Director deny the request to allow
soil nails into the 16t" Avenue S right-of-way.
Staff Recommendation:
Development Services Reviewer
Development Services Manager
Traffic Division Reviewer
Traffic Division Manager
lirrricrl Date
1 fJ
0
I fi 1 Oar 2or Sl
Approve
Deputy Director ze�dA r� �(_[ ❑
Director Decision zkl 4 lot1> ` I P ❑
K:\DEVELOPMENT SERVICES\STAFF IOLDERSI OL 15lreel Mod\MHS Off -Campus Em Clinic SM.docx
Scan completed form into Amanda folder
l 8 - to y(po o - 5m
RECEIVED
SEP 2 8 2018
CITY OF FEDERAL WAY G EO E N G I N E E RS-.�g
COMMUNITY DEVELOPMENT 1101 South Fawcett Avenue, Suite 200
Tacoma, Washington 98402
253.383.4940
September 27, 2018
City of Federal Way - Department of Community Development
33325 8t" Avenue South
Federal Way, Washington 98003
Attention: Cole Elliot, Development Services Manager
Subject: Modification Request
Building Permit Number 18 102604 00
MultiCare Health Systems Off -Campus Emergency Clinic
Federal Way, Washington
File No. 2868-017-02
This letter presents a Modification Request for a permanent retaining wall along the west site boundary of
King County Parcel 0421049033, located at approximately 29805 Pacific Highway South in Federal Way,
Washington. A vicinity map is provided as Figure 1. On behalf of MultiCare Health Systems, we are
requesting a modification to allow construction of a soil nail wall where some of the soil nails may extend
beyond the property boundary into the City of Federal Way right-of-way.
The west side of the existing site is bounded by a steep slope (between approximately 1.5H:1V
[horizontal:vertical] and 1H:1V) that leads up to 16th Avenue South. To accommodate the proposed
improvements, a retaining wall is planned near the west site boundary to support the slope and roadway.
A site plan showingthe proposed location of the wall is provided as Figure 2. The face of the proposed wall
will be located within the parcel boundary. The free height of the wall will be about 19 feet near the south
end of the wall and will decrease to less than 5 feet at the north end.
The project team is proposingto construct portions of the wall greater than about 10 feet in height as a soil
nail wall system. For wall heights less than about 10 feet, the design will likely involve either a cantilever or
gravity wall system that will lie entirely within the property boundaries. No tiebacks or nails will be used for
this portion of the wall.
A soil nail wall consists of drilling and grouting rows of steel bars or "nails" behind the excavation face as it
is excavated and then covering the face with reinforced shotcrete. The placement of soil nails reinforces
the soils located behind the excavation face and increases the soil's ability to inhibit a mass of soil from
sliding into the excavation. Soil nail walls are a "passive" earth retention system meaningthat the nails are
not tensioned after installation. Soil nails are different than tiebacks; tiebacks are typically longer than soil
nails and are tensioned after installation.
City of Federal Way — Department of Community Development September 27, 2018 Page 2
Conceptual wall cross sections are provided as Figures 3 through 5. Figures 3 and 4 show conceptual soil
nail wall configurations and Figure 5 shows a conceptual cantilever soldier pile wall configuration. At the
location of the maximum wall highest (Cross Section A -A', Figure 3) we expect that the soil nails will be
around 15 feet long and will be installed as a declination of around 20 degrees from horizontal. As shown
on Figure 3, we anticipate the soils nails would extend a maximum of around 3 feet beyond the property
line. At the location of the property line we expect that the soil nails will be around 15 feet below ground
surface. The nails would not extend below the 16th Avenue South roadway. As the retained height of the
wall decreases, we expect that the length of the soil nails will also decrease and by the time the wall height
is around 11 feet (Cross Section B-B', Figure 4) the soil nails would not extend beyond the property
boundary.
In areas where the wall is constructed as a cantilever or gravity wall (Cross Section C-C', Figure 5), the wall
would be located within the property boundary.
We understand that current City of Federal Way Policy does not allow "tiebacks" to extend into City right-of-
way. We are requesting a modification to allow construction of a soil nail wall where some of the soil nails
will extend beyond the property boundary. As shown in the figures and described above, the soil nails would
be located a significant distance below ground surface at the property line and would not extend below
16th Avenue South.
In our opinion, the existing slope on the west property boundary within and outside of the property boundary
is over -steepened and likely does not meet generally accepted factor of safety requirements with regards
to seismic slope stability. The proposed retaining wall will be designed to withstand a design earthquake in
accordance with the 2015 International Building Code (IBC). In our opinion the wall will reinforce the slope
that supports the 16th Avenue South roadway and will likely improve the global seismic stability of the slope
and roadway during the design earthquake event.
We appreciate you taking the time to review this Modification Request. We are available to discuss the
conceptual layout further or answer any questions you may have. Our contact information is provided below.
Respectfully submitted,
GeoEngineers, Inc.
Brett E. Larabee, PE
Geotechnical Engineer
biarab e@ eoen ineers.cam
253.722.2436
BEL:MM:tt
Attachments: Figures 1 through 5
M F n ur, E
Associate eological Engineer
mo-rthur@ e e iners.com
253.722.2431
Disclaimer: Any electronic form, facsimile or hard copy ofthe original document (email, text, table, and/orfigure), if provided, and any attachments are only a copy
ofthe original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record.
GEOENGINEER,
File No. 2868-017-02
. S 276th St
I`
s a
{�®
9 5 277th PI
y
a 5
Star take Rd
N
by
a S 279th St
�M1r�
n
Y�
e
Y
5 2801h St
77
•
-
Y 5282nd St n
N S282nd
St
s
~
'
a`
s S 284th St
j
S 284th St
S 284th PI
S 264th
S 285th St
y,
a y
iiil k
S,�
^_
A
S 286M St
N
� 2b
_
N N
11.4
N
v
N S:81
r $ i
5288th St
5 288th St i�
J NM-6m Deramlary Qt 1
¢'
'St r
S 2900 N
— r S,?g
"' �,Lo rst St- ry
SW 292nd St
S292nd
3• t
L
SW 293rd St a
cJ 5 293rd S[ i
?
c ,
v a
'•'
h
a
m
1 •
m'
:. 297[h.$
S1 �F
S 296th St
AfRRI�iH: HILLS
J
! i
S296thN
'-
SW 298th PI
a
'
•
S 2981h St S 298th S[ SZ98th
5[
n St
52�^s5t
SZ•
°" ''""""„"`
SITE
Il'
MAR CHERI —
PUGET SOUND s a
3p
i !'ijl
S299t'St
Palnr Rd
L
HILLS
m
—
y m
5300th S[- IJJI
Sf00
Dash
'• 5'N
t
a
n YBldwooe eementary o i
•
M1
S Dash PYint Rd
^ S 302nd 5[
r+iz
L
5302nd 5f rs
5303rd St
N
�fll
�S302nd1
�
.
"�Sw l041h H
L 5 304th S['^
o
; S 304[h St
S 3041h Sr-
I+
S 304th St
5W 32I§tt15l.
5 304th PI
W '
S 304th St
n
53051h St
..
Sd.W
lh St
S 308[h St -- N ¢'
N � 5 308[h S[
S 308th St
1
4
=
�
trie Grace eemennry
m
m
t
s
v,
PAS 310th St
r
+
MIRROR LAKE
. ��
s t
l
Sr
i O
`r
I;
5 3121h
St S 312th St
5 312th
0-1N.
•
S 312th
5t
w
y a
5313th St
'I
•�
K
",
w
•
4i
A
a n Q �5314th St
x
Q S 314th Sr
a'
y
t;vn%Wrerel
a
16mr141e Ekrn ury
c 5315th St D `
o` N
N
�16thSt
St 8
I.. k.•+. fI+
S 316[h PI Sdnd
H
a
S316th St ®
5 316th St
m
RST—R[8h
S 31"t,St S
e
i n. w,rm
S 311th PI ,3170,St � Y
SOW
o
e'
. 5 317[h St
5 316th PI
k
�
Sea tie
Rtmton
Kent
Tacoma
Notes:
1. The locations of all features shown are approximate.
2. This drawing is for information purposes_ It is intended to assist in
showingfeatures discussed in an attached document. GeoEngineers, Inc.
cannot guarantee the accuracy and content of electronic files. The master
file is stored by GeoEngineers, Inc. and will serve as the official record of
this communication.
Data Source: Mapbox Open Street Map, 2015
Projection: NAD 1983 StatePlane Washington North FIPS 4601 Feet
N
W E
S
2,000 0 2,000
Feet
Vicinity Map
Federal Way Free Standing Emergency Center
Federal Way, Washington
GMENGINEER Figure
I S— l0q(000
.ie•.;�s<
!X FYI
1L Mfl [ l•ff l
IVrw ,l T••+�i +"
k'wcli a -I •�'
432' {
f I
3�2� ..
W,.uiN�rlJ
f4linnrf• a'J� I`
,
; ��
�
b
,
435i
- __•1
-.-
4 AIL �i.U�,•' ._'. �II
li,
438
'
I
_• 4'37 __._
I
!
439
438
+
¢
j
_ 439r--
C
r
i•J ---
443
AAI�
.. J
4+4.4
_ p$3 m"
II�
wnpA�a=u�wm�
44A
el'y�
1
AA5
�AAT i� '
I '-•
B.
C
a
ii
i5l i !ryI
448
1
r45�
•4��7
.
449
I.
0 ,
450
, l
43
A
.111
fa riuwK+�»
a_cnciEs.n��na�
r s�wln.l
F rpASH
uN
stop
n cminaa
NIA='clxi
I Fs-f rav .n it r.fus
FIM•tl
PIVF
•wCIL�'=41-16 Y — —
rn;i c•rrr,.
Legend
+� Site Boundary
B-1+ Baring by GeoEngineers, 2017
Notes:
1. The locations of all features shown are approximate.
2. This drawing is for information purposes. It is intended to
assist in showing features discussed in an attached document.
GeoEngineers, Inc. cannot guarantee the accuracy and content
of electronic files. The master file is stored by GeoEngineers,
Inc. and will serve as the official record of this communication.
Data Source: Background or Aerial from XXXX dated xx/xx/xx.
Projection: XX State Plane, XX Zone, NAD83, US Foot
RGIr_FivFn N
SEP 2 8 20% WI#E
Cr Y OF FaiERiu-My S
COMMUNITY a 50
Feet
Site Plan
Federal Way Free Standing Emergency Center
Federal Way, Washington
GMENGINEERS� Figure 2
A
A�
to soil nail at
(East)
(west)
it
R �
� property line = 15
460
- _ _
-
- — - — --feet
460
0
Existing Grade
450
m
/ -IT---
LL
440
-�� hE"�r►� till'
l
Soil Nails will
extend
l5
approximately 3
W
W
430
feet past property
- — --0
line
1S'
U
420 -
-- -
- _ - — -
- —
420
Proposed Grade
G
a
H
410
0 10
20
i
30 40 50 60
70 so 90
410
100
a
r
M
0
Distance (Feet)
00
m
00
W
i
ti
ppab
n
a
Cross -Section A -A'
5
Federal Way Free Standing Emergency Center
10 0 10
Federal Way, Washington
g
w
Horizontal Scale In Feet
1❑ ❑ 1❑
G M E N G I N E E R5� Figure 3
Vertical Scale in Feet
Vertical Exaggeration: 1X
C C1
(west) cam)
460 --- -- -
- - - ---- - - 460
Existing Grade !
1
450 - - ... I - - - ---- 450
II
� I
� l
1 - -- — 440
0 440
w
C �
r '
w 430� 1C -- - LU
430
e;
420
420 - - -- —
9
of
P posed Grade
U
410 410
0 10 20 30 40 50 60 70 80 90 100 110 120
o Distance (Feet)
r
n
0
1
.a
O
O
ti
w
Cross -Section C-C'
a
Federal Way Free Standing Emergency Center
10 0 10 Federal Way, Washington
Horizontal Scale in Feet
10 Vertical Scale in Feet �� G M E N G I N E E RS Figure 5
°' Vertical Exaggeration: I-X