Report 12/20/02 FRI 09:14 FAX 503 670 9147 CARLSON TESTING tI 001
k ar s oxi Ge c l /11p of : : • : : Main Office Salem Office Bend Office
• • • • • • • • • • f O. Box 23814 4060 Hudson Ave., NE P.O, Box 7918
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A Division of Carlson Testing, inc. • • • : T igard, Oregon 97281 Salem, OR 97301 Bend, OH 97708
Geoteehnical Consulting Phone (503) 684 -3460 Phone (503) 589 -1252 Phone (541) 330 -9155
Construction Inspection and Related Tests FAX (503) 670 -9147 FAX (503) 589 -1309 FAX (541) 330 -9163
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December 20 , 0 2 • • • • • ' • •' • :.. 1 t a o v a —� az 7
Albert Shields
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City of Tigard Bi3itdii C deg n�or�$r1>rnt
13125 SW HaII Qouk vaed • • • • • • • •
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Tigard, Oregon 9722' •
Mr. Shields,
The purpose of this letter is to provide you with information regarding the rebuilding of
the rockery walls on lots 2 through 10 of the Erickson Heights Subdivision. We have
provided Renaissance Homes with a rockery wall design and a confirming agreement to
observe the reconstruction of the rockery walls. Provided our confirming agreement is
signed and returned to our office prior to the commencement of work, Carlson
Geotechnical will observe the reconstruction of the walls.
The general plan for reconstruction the walls is to remove each wall, excavate subgrade
soils to firm material, and rebuild the wall in accordance with our rockery wall design.
Once a particular wall is removed, we will observe the subgrade soils and make the
proper recommendation for over excavation of the subgrade. Once the subgrade is over
excavated, we will observe the keyway, foundation rock, and placement of the wall drain.
We will also observe compaction of the backfill aggregate, footing to slope (or adjacent
wall) set backs, and wall batter. Provided these items are performed in accordance with
our recommendations, we will provide a final letter of rockery wall observations to the
City of Tigard and Renaissance Homes.
If you have any further questions or comments, please contact our office.
Brian C. Ranney, G.I.T.
Geotechnical Staff
1sson v' eAtechth SO 2881 cal: : • • . • Ma x 2
a 381 6 Salem Office Bend Office
• • • • • • • • • • •O. 4060 Hudson Ave., NF P.O. Box 7918
A t�ivislon cf Carlson Testing, ►no • • . • • • • • • 71gtt, Oregon 97251 Salem, OR 97301 Bend, OR 977C8
Gsoteohnioal Consulting • •
• • • • • • • !:tune (503) 654.3460 Phone (503) 569 -1252 Phone (541) 330.9155
Construction Inspection and Related Tests FAX (503) 870..9147 FAX (503) 689 -1308 FAX (541) 330.9163
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December 11, 2002 • • • • • • •' •
Mr. Steve Hunt • • • ... • • .. ..
Renaissance Homes • •
1672 SW Willamette 1:, ljs flrtvq • • • • • • • •
West Linn, Oregon 97068
Confirming Agreement for Construction Observation Services
Erickson Heights Rockery Walls Lots 1 -10
SW Kable Street
Tigard, Oregon
INTRODUCTION
Carlson Geotechnical is pleased to submit this confirming agreement to observe the re- building
of the upper rockery walls on lots 1 through 10 of the Erickson Heights Subdivision in Tigard,
Oregon. We have performed numerous observations of these rookery walls, the results of
which were presented in our Summary Report of Rockery Wall Observations dated October 25,
2002. In that report we recommended that the upper walls be re- built, and we provided a
general detail and written recommendations for rebuilding the rockery walls.
PURPOSE AND SCOPE
The purpose of our geotechnical construction observation services will be to confirm that the
rockery walls are re - built In accordance with the recommendations contained in our Summary
Report of Rockery Wall Observations. Our specific scope of services will include the following:
• Observe rockery wall subgrade solis.
• Observe boulder placement.
• Observe wall backfill compaction.
• Observe wall batter.
• Maintain periodic documentation of the construction activities and provide field
reports to Renaissance Homes and the City of Tigard.
• Submit a final letter of compliance regarding geotechnical- related activities.
FEE ESTIMATE
It is difficult to accurately estimate our total construction observation fees because our
involvement will depend on the rate at which construction proceeds, weather conditions, and the
number of site visits required. We anticipate that our services will be required on a part -time,
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Erickson Heignis Lots 1 -10
Tigard Oregon • •e• ••
December 11, 2002 . • • • • • • • • •
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on -call basis during • .arthwork ouratigns; however, we are prepared to perform full time
observation at yc it rejlueot
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For budgetary purposes, we have assumed that each part -time visit will require a total of 3 hours
and will cost approximately $325 each. Each full time visit will require a total of 8 hours and will
cost approximately $650.00 each. This cost estimate includes vehicle mileage, and preparation
and review time for field reports. Our construction observation services will be conducted by a
member of our geotechnicel staff and will be billed on a time- and - expense basis. All charges
will be provided in accordance with the attached Schedule of Charges and Terms and General
Conditions for Geotechnical Services. We are prepared to maintain a high level of
communication with the involved parties to keep close control of estimated and actual demand
for our construction observation services.
Satisfactory earthwork performance depends to a large degree on the quality of construction.
Sufficient observation of the contractor's activities is a key part of determining that the work is
completed in accordance with the construction drawings and specifications. Subsurface
conditions observed during construction should be compared with those encountered during
subsurface explorations, and recognition of changed conditions often requires experience. We
recommend that qualified personnel visit the site with sufficient frequency to detect whether
subsurface conditions change significantly from those observed to date and anticipated in this
report.
We recommend that rookery wall subgrades, placement of boulders, drain placement, wall batter,
and compaction of wall backfill be observed by the project geotechnical engineer, or their
representative.
SCHEDULE
Because observation is typically performed on an on -call basis, this agreement assumes that the
earthwork contractor is held contractually responsible for scheduling observation. Observations
should be scheduled a minimum of 24 hours in advance of when you would like the observation to
be performed.
CLOSURE
We appreciate the opportunity to submit this proposal and look forward to working with you on
this project. Please formally provide your authorization of the work described herein by signing
a copy of this proposal and returning it to our office. At your request, upon receiving written
Carlson Geotechnical Page 2 of 3
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Erickson Heights Lots 1 -10
Tigard, Oregon • . . . • • . .• . • •
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December 11, 2002• • • • • •
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authorization to proceed, we will notify the City of Tigard by letter to inform them that we have
been retained to pb to se�piDlc n9
••• df the walls. Please feel free to call if you have any
questions or require a ditiorel4nfvrtriation
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Sincerely,
CARLSON GEOTECHNICAL
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Brian C. Ranney, G.I.T.
Geotechni Staff
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J ne M. Niemer, P.E.
•ai Geotechnical Engineer
JA--
Terms and General Conditions for Geotechnical Services •
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The terms and conditions of this etter are hereby accepted, and authorization to proceed with
the above scope of work is give,' by the following signature. I have secured or verified right -of-
entry for this we k.
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By 4 a �� 0 Date ,,� D •
Firm `t '�t-� � 4 - / - J 5. 1:#
Doc ID: P: \GEOTEI \Projects (Engrec)\2001 ProjectslErickson Heights Subdlvision\cent ming agreement re - build rock rralls.DOC
Carison Geotechnical Page 3 of 3
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s ®n Geotechnical
Main Office Salem Office • .P.O. Box 23814 40 NE Bend Office
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A Division of Carlson Testing, Inc. : : • • • • • • • • Tig rcj Oregon 97281 Salem, OR 97301 Bend, OR 97708 • Geotechnical Consulting ••• • • • • • • • Phone 684 -3460 Phone (503) 589 -1252 Phone (541) 330 -9155
Construction Inspection and Related Tests: : : : • • • • FFLY. x503) 670 -9147 FAX (503) 589 -1309 FAX (541) 330 -9163
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CGT No. G0101867.E • • • • • • • • • . . • • • •
Permit No. Unavailable • • • • • • •
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FIELD OBSERVATION REPORT
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DATES COVERED: : Octpb -, 1 „2Q0:. • • ••
PROJECT: : EGUs6p•H :ig:ltt 5utidivision - Lot 5
ADDRESS: 10788 SW Kable Street, Tigard, Oregon
BY: Brian C. Ranney, G.I.T.
WEATHER: Cloudy, —60 °F
PURPOSE OF VISIT: Rockery Wall Observation
Carlson Geotechnical (CGT) Geotechnical Staff Brian Ranney arrived on site at 9:30 am as requested by Steve
Hunt of Renaissance Homes (RH). The purpose of my visit was to observe the rockery walls located at the back
of lot 5.
At the time of my visit, the proposed residence was complete. Four rockery walls had been constructed in the
backyard area of the residence. We previously reviewed these walls and observed that since they were not over
four feet high, and they were not surcharged by the residence or adjacent walls, that they were not engineered
walls. However, at the prompting of the City of Tigard's letter dated September 24, 2002, we observed these walls
again for their general quality of construction.
The first, upper wall is set back from the residence approximately 15 to 26 feet and was approximate 4 feet high.
The batter of this wall ranged from nearly vertical to approximately 1 H:4V. The wall was backfilled with silt soils
that I could probe up to 4 feet with relative ease. The stacking of the boulders in this wall was generally poor. My
observations suggest that the wall was not embedded into the subgrade.
The second wall was approximately 4.5 feet high, had a batter ranging from nearly vertical to approximately
1H:4V, and was backfilled with silt. I could probe the silt backfill up to four feet with relative ease. The stacking of
this wall was generally poor, and the wall is experiencing a surcharge from the wall above it. My observations
suggest that the wall was not embedded into the subgrade.
The third wall was approximately 4 feet high, had a batter of approximately 1 H:4V, and was backfilled with 2 inch
minus aggregate. Probing of the backfill indicated that the aggregate was medium dense. The bottom course of
boulders appeared to have been embedded into the subgrade.
The fourth wall was also approximately 4 feet high, generally had a batter of 1 H:4V, and was backfilled with 2 inch
minus aggregate. Probing of the backfill indicated that the aggregate was medium dense. The bottom course of
boulders appeared to have been embedded into the subgrade.
I left the site at 9:45 am.
Brian C. Ranney, G.I.T. r Jeanne M. Niemer,f-
Geotechnical Staff Principal Geotechnical Engineer
Note: Our reports pertain to the locations observed at the time of our visit only. Information contained herein is
not to be reproduced, except in full, without prior authorization from this office.
DISTRIBUTION: Steve Hunt, Renaissance Homes. Fax: (503) 670 -8663
Steve Hunt, Renaissance Homes. Fax: (503) 656 -1601
01/02/03 THU 11:07 FAX 503 670 9147 CARLSON TESTING 10 00
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* RbdK SL'.E SdHEBULE = 250D + 250) LBS. ROCKERY WALL DESIGN
•M•(FT3 Ml N'yv l,.BS.I' .TYPICAL SIZE (IN.) MAXIMUM WALL HEIGHT (H) = 4 FEET
• • • • • • • • • • • • • • • • • ' • ' • • • 3 X 26 X 18 DRAWING NOT TO SCALE • • 4 •••• • 1,5150•
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25 X 25 X 25
••..••• • 1,000 .. , . 28X25X16
_ _ • ,. . _ . . . • . 22X22X22
• • • 4 LEVEL TO 2H:1V MAX. SLOPE
't Gm r. • • ' 18X1 19 22 X 1 XX 114
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COMPACTED SILT
OR CLAY SOIL
o ,j (12 to 24 INCHES
, THICK)
f,, A' °a °fir
�$ �� � f - p . R as °a
11 1 �� a:,0: oQ0�..:
D —
r.. , - ORE - .. N - - - - -, .: � Nil' STABLE TEMPORARY CUT
S = ` •-'02 (SLOPE ANGLE VARIES)
� �j' 4 ±1 MIN. WT. °p U
7 250D +250 - o e�
B ��•�` - ® a 0 C° " ▪ ----- 4 " CRUSHED AGGREGATE,
q a o °
I \� 40Y-%; :0 COMPACTED IN 12 INCH LIFTS
- . U�� QlJ
0.35H ' _ °
1 —►{ " °uA^ 11/2 " -O CRUSHED AGGREGATE
E9E
F � i f WITH NO MORE THAN 7% FINES
• �P _ °R PASSING THE No. 200 SIEVE,
b/1 'O LIGHTLY TAMPED
/JAN ; , ° 5 1
0 2 2003 6 IN. o :..A.5 . -- .� 4 IN. DIAM, MIN. PERFORATED PLASTIC PIPE
CITY OF �r „ SCHEDULE 40 or ADS HIGHWAY GRADE • BUI LDI NG ° V S R 14
KEYWAY I
• 0.4H MIN. FOR OSHA STABLE ROCK,
0.5H MIN. FOR OSHA 'TYPE A" SOILS. AND
CONSTRUCTION NOTES 0.61-I MIN. FOR OSHA "TYPE B" SOILS
1. For walls supporting engineered fill, the fill should be overbuilt and the w all constructed against an excavation into already
compacted fill.
2. Keyway subgrade and embedment depth should be verified by CARLSON GEOTECHNICAL
3. Rocks should have a cubical, tabular, or semi- rectangular shape that roughly matches the space created by the previous rock
course. Rocks should be laid flat with the long dimension oriented perpendldular to the wall and extending towards the excavation
face. Rocks should be staggered such that each rock bears on at leasil two rooks below and vertical joints are discontinuous. Rock
placement and wall integrity should be checked by builder) by lightly hammering on the top of each rock with excavator bucket.
4. Minimum rock sizes should be determined using the ROCK SIZE SCHEDULE above, where D is the distance from the base of the
rock to the top of the wall. Rocks Should be no smaller than 500 lbs,
5. Voids greater than 6 inches wide where there is no contact between adjacent rocks should be chinked with a small rock,
6. Backfill behind the rocks should consist of an average 12 -inch -wide sheet of 4 "-0 well graded gushed aggregate with no more than
7% fines passing the U.S. Standard No. 200 sieve. Backfi should be placed in lightly compacted to an unyielding state in 12 Inch
lifts has each course of rocks is placed.
" - 04i Carlson Testing, Inc.
_ P.O. Box 23814 Erickson Hei4hts Subdivision CGT Job No. G0101867.E
_ au'La Tigard, Oregon 97281
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Tuesday, Novembe 05 , 20 ••• •••
02
••• •••• • • •• •• OREGON • •
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...•• .•• .. Robert D. Wood, VP pf Gppstr�ict�ofl ; ; Ft
Renaissance Properties
1672 SW Willamette Falls Dr.
West Linn, OR 97068
RE Erickson Heights II, Retaining Walls and Fill, Lots #2 -10.
Dear Robert:
Thank you for your cooperation in taking steps to resolve the issues concerning the rockery
retaining walls and fill on Lots #2 - 10 at Erickson Heights II. Permit applications and plans
regarding the subject walls and fill have been received by the City of Tigard. The lot
numbers, street addresses, and permit numbers are listed on the attached exhibit.
The City recognizes this submission as meeting the timeline requirement set forth in the
September 24, 2002 Notice of Violation letter sent to Renaissance but, as you know, the
application and plans do not resolve or propose corrections regarding the issues raised about
this site in that September 24 letter from the City, the September 17"' report from Kleinfelder,
Inc., or the October 21 report from Carlson. We will accept these plans as a pro -forma
submission pending receipt of revised and updated plans upon which we will conduct a formal
plan review.
Please submit plans revised to address and correct the issues and concerns raised in the above
letter and reports.
We have not yet assigned a permit number to the application for lot #7, 10690 SW Kable. The
two rockery walls on that lot were included in the original plans for the subdivision. If
corrective work on those walls is required before the design engineer, Carlson, can verify the
adequacy of their construction and issue a final acceptance letter, please let us know and we
will issue a permit on this property. If Carlson is able to approve these walls as having been
constructed in accordance with their original plans and will issue a final acceptance letter on
them, specific for this lot, please forward that letter to us.
Please note that the City's September 24t letter provided 30 days for submission of the permit
applications and a total of 90 days or 60 days additional for completion of all corrections,
including plan review, construction, inspection, and approval. As of today, November 5` 52
days remain of that 90 day period, which ends at close of business on Friday, December 27,
13125 SW Hall Blvd., Tigard, OR 97223 (503) 639 -4171 TDD (503) 684 -2772
K.
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2002. Please note fuJthq that ,F,iial inspection 4pproval will require submission of a final
acceptance letter frill :
•00 000 • 04141 • •••
Sincerely,
.., ••• • • 00 00
6 ""` • •.
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Gary Lampella, Building Official
cc: Steve Hunt, Hap Watkins, Albert Shields
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ERICKSON HEIGHTSIL, RUTAINING WALLS AND FILL
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Lot No. Permit No. Street Address
2 SIT2002 -00028 10856 SW Kable St.
3 SIT2002 -00029 10832 SW Kable St.
4 SIT2002 -00030 10810 SW Kable St.
5 SIT2002 -00027 10788 SW Kable St.
6 SIT2002 -00031 10722 SW Kable St.
7 SIT2002 -000XX 10690 SW Kable St.
8 SIT2002 -00032 10652 SW Kable St.
9 SIT2002 -00033 10630 SW Kable St.
10 SIT2002 -00034 10600 SW Kable St.