HomeMy WebLinkAboutSoil Log Encl. - COM Engineering / Geo-Tech Reports - 5/27/2014 � 1
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To: Wade Jensen, Erickson McGovern Architects
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From: James Brigham, P.E. and Zach Logan
Date: May 27, 2014 rG4L
Re: North Mason High School Geotechnical Checklist
Job No:T13096
E3RA, Inc. is pleased to provide additional comments addressing questions by Mason County
concerning bulletin points#10 and #12 on their Submittal Checklist for a Geotechnical Report,
as it pertains to the Geotechnical Engineering Report submitted by E3RA, Inc. on October 25,
2013 for the planned developments at the new North Mason High School.
#10—An analysis of both onsite and offsite impacts of the proposed development.
Given the nature and the location of the planned improvements, it is our opinion that there will
be no offsite impacts resulting from the new construction. Additionally, it is our opinion that the
planned locations for the new facilities are globally stable, and no adverse onsite impacts
should be resultant as well. As with any construction requiring earthwork activities, there is the
risk of localized erosion which could destabilize portions of the site adjacent to the new
improvements. In the site preparation subsection of our report, located on pages 7-9, we
provide recommendations to mitigate erosion during the earthwork phase of the new
construction.
#12 — Recommendations for the preparation of structural mitigation or details of other
proposed mitigation.
We address structural mitigation primarily on pages 9-12, where we discuss spread footings,
slab-on-grade floors, asphalt pavement, and structural fill. The recommendations found within
these subsections are provided as guidelines to be followed in order to prevent structural
damage to the new facilities. Additionally, on pages 7-9, in our site preparation subsection, we
provide recommendations for erosion and landslide mitigation.
E3RA Inc.—9802 29th Ave W#13102-Everett WA 98204 —425-356-3372—425-356-3374(fax)
✓ E3RA Inc.—PO Box 44840-Tacoma WA 98448—253-537-9400—253-537-9401 (fax)
❑ E3RA Inc.— 13023 NE Hwy 99 Ste 7-36-Vancouver WA 98686—971-201-7359
(6/12/2008) Michael MacSems-'Geotechnical Report Review Checklist 6-08.doc Page 1
Mason County Review Checklist
For a Geotechnical Report
Instructions:
This checklist is intended to assist Staff in the review of a Geotechnical Report. The Geotechnical Report
is reviewed for completeness with respect to the Resource Ordinance. If an item is found to be not
applicable,the Report should explain the basis for the conclusion.The Report is also reviewed for clarity
and consistency. If the drawings,discussion,or recommendations are not understandable,they should be
clarified. If they do not appear internally consistent or consistent with the application or observations on
site,this needs to be corrected or explained. If resolution is not achieved with the author,staff should refer
the case to the Planning Manager or Director.
Applicant's Name: hov�\n 1 1.1�o�n • -�_- �cc,
,,pp A c'w�
Permit# f6 1 �-o 3 cParcel# ) Z Z G E - Z Z =6c�,O o 12 2 o ff-Z3 - 6 0 crh)
Date(s)of the Document(s)reviewed: 511�/14
(1) (a)A discu ion of general geologic conditions in the vicinity of the proposed development,
OK? Comment:
(b) A discussion of specific soil types
OK? T Comment:
(c) A discussion of ground water conditions
OK?V Comment: 3 , 3
(d) A discussion of the upslope georpor hology
OK? v Comment: rV C Vti4 it 1,�}-
(e) A discussion of the location of upland waterbodies and wetlands
OK? ;/ Comment: )/V A- 10, c I - R I1.14-
(f) A discussion of history of landslide activity i the e activity in the vicinity,as available in the
referenced maps and records
OK? G Comment: �I
(2) A site plan which identifies the important development and geologic features.
OK? ✓ Comment:
(3) Locations and logs of exploratory holes or probes.
OK? ✓ Comment: ( I-
(4) The area of the proposed development,the boundaries of the hazard, and associated buffers and
setbacks shall be delineated(top, both sides,and toe)on a geologic map of the site.
OK? V Comment: /'V�ks [ L' -i� 1
(5) A minimum of one cross section at a scale w ich adequately depicts the subsurface profile, and
which incorporates the details of proposed grade chajiges.
OK? Comment:
(6) A description and results of slope stability ana yses performed for bothLstatic aricf seismic loading
conditions.Analysis should examine worst case failures.The analysis should include the
Simplified Bishop's Method of Circles.The minimum static safety factor is 1.5,the minimum
seismic safety factor is 1.1.and the quasi-static analysis coeffients should be a value of 0.15.
OK? ✓ Comment: ty' 14 a'e C k,.-k,� ':,
(7) (a)Appropriate restrictions on placement of drainage features
OK? ✓ Comment: `4
(b) Appropriate restrictions on placement of septic drain fields
OK? io Comment: VQ t -5/Z mu
(c) Appropriate restrictions on placement of compacted fills and footings
OK? +' Comment: 41 Z
(d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other
slopes on the property.
Page 1 of 2 Form Effective June 2008
(6/12/2008) Michael MacSems-Geotechnical Report Review Checklist 6-08.doc Page 2
OK? ✓ Comment: N/A
(e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of
other slopes on the property.
OK? ' Comment: ;
(8) Recommendations for the preparation of a detailed clearing and grading plan which specifically
identifies vegetation to be removed,a schedule for vegetation removal and replanting,and the
method of vegetation removal.
OK? V Comment: ;
(9) Recommendations for the preparation of a detailed temporary erosion control plan which identifies
the specific mitigating measures to be implemented during construction to protect the slope from
erosion,landslides and harmful construction methods.
OK?_ V Comment: !�I.
(10) An analysis of both on-site d off-site impacts of the proposed development.
OK? '✓ Comment: ey S /Z1 Nlo" .
(11) Specifications of final development conditions such as,vegetative management,drainage,
erosion control,and buffer widths.
OK? V Comment:
(12) Recommendations for the preparation of structural mitigation or details of other proposed
mitigation. , y.
OK? Comment:
(13) A site Apdrawn to scale showing the property boundaries,scale,north arrow,and the location
and nature of existing and pro,pposed development on the site.
OK? ✓ Comment: `>IL, C U•G C
Are the Documents signed and stamped?
Type and#of License: ��T�S S�(/�„�,� �\A��lk.A�✓
If not approved,what is the next action/recommendation for further action?
Reviewed by V Y i on
Time spent in review:
SECOND REVIEW/UPDATE:
Reviewed by on
Time spent in second review:
THIRD REVIEW/UPDATE:
Reviewed by on
Time spent in third review:
Disclaimer: Mason County does not certify the quality of the work done in this Geological Assessment
Page 2 of 2 Form Effective June 2008
Page 1 of 1
r
Michael MacSems - Section #7 -North Mason Septic
From: Eric Nelson<eric@,hainline.net>
To: "'MMS@co.mason.wa.us"' <MMS@co.mason.wa.us>
Date: 5/28/2014 3:29 PM
Subject: Section#7 -North Mason Septic
Attachments: 2013-15-A 1.00V2_11 x 17.pdf
Michael,
With respect to Section#7, we have the attached comment from the designer, as well as the attached site plan
noting the Tank and field locations for your use.
"The existing drain field will be utilized for the new North Mason High School and the existing high school (future
remodel and will become the Hawkins Middle School). New septic tanks will be added adjacent to the existing
drainfields. A site plan is attached for reference."
I hope this helps.
Eric Nelson
Hainline &Associates
253-380-3947
file:///C:/Users/mms/AppData/Local/Temp/XPgrpwise/53 8600DAMasonmai11001613462... 5/28/2014
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OVERALL ARCHITECTURAL SITE PLAN A 1.00
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Mason County Department of Community Development
Submittal Checklist For a Geotechnical Report
Instructions:
This checklist must be submitted with a Geotechnical Report and completed, signed, and stamped by the
licensed professional(s)who prepared the Geotechnical Report for review by Mason County pursuant to
the Mason County Resource Ordinance. If an item found to be not applicable, the report should explain
the basis for the conclusion.
Applicant/Owner: North Mason School District Parcel#: 12208-22-60000, 12208-23-60010
Site Address: 150 E. North Mason School Road Belfair,WA 98528
(1) (a)A discussion of general geologic conditions in the vicinity of the proposed development,
Located on page(s)
(b) A discussion of specific soil types
Located on pages) a , q
(c) A discussion of groun�Lwater conditions
Located on page(s) `` I S
(d) A discussion of the upslope geomorphology
Located on page(s) /A `�h F. _,t t t i 5
(e) A discussion of the location of upland waterbodies and wetlands
Located on page(s) ;ti
(f) A discussion of history of landslide activity in the activity in the vicinity, as available in the
referenced maps and records
Located on page(s)
(2) A site plan which identifies the important development and geologic features.
Located on Map(s) )=°O,`- 1 t z_ 0: -,-`-
(3) Locations and logs of exploratory holes or probes.
Located on Map(s)
(4) The area of the proposed development, the boundaries of the hazard, and associated buffers and
setbacks shall be delineated(top both sides, and toe)on a geologic map of the site.
Located on Map(s) Ai
t ,,. .
(5) A minimum of one cross section at a scale which adequately depicts the subsurface profile, and
which incorporates the details of proposed grade changes.
Located on Map(s)
(6) A description and results of slope stability analyses performed for both static and seismic loading
conditions.Analysis should examine worst case failures.The analysis should include the
Simplified Bishop's Method of Circles.The minimum static safety factor is 1.5, the minimum
seismic safety factor is 1.1. and the quasi-static analysis coeffients should be a value of 0.15.
Located on page(s)
(7) (a)Appropriate restrictions on placement of drainage features
Located on page(s) A i%
(b) Appropriate restrictions ronjplacement of septic drain fields
Located on page(s)
(c) Appropriate restrictions on placement of compacted fills and footings
Located on page(s)
Page 1 of 2 Form Effective June 2008
Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report.
' (d) Recommended buffers from the landslide hazard areas shoreline bluffs and the tops of other
slopes on the property. �
,l 1
Located on page(s) ,"v i ,: �.. ti` ��_,�. �.,
(e) Recommended setbacks from the landslide hazard areas shoreline bluffs and the tops of
other slopes on the property.
Located on page(s) � I r,
(8) Recommendations for the preparation of a detailed clearing and grading plan which specifically
identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the
method of vegetation removal.
Located on page(s)
(9) Recommendations for the preparation of a detailed temporary erosion control plan which
identifies the specific mitigating measures to be implemented during construction to protect the
slope from erosion, landslides and harmful construction methods.
Located on page(s)
(10) An analysis of both on-site and 7 off-site impacts of the proposed development.
Located on page(s)
(11) Specifications of final development conditions such as, vegetative management, drainage,
erosion control, and buffer widths.
Located on page(s) q _ C`
(12) Recommendations for the preparation of structural mitigation or details of other proposed
mitigation. _
Located on page(s)
(13) A site map drawn to scale showing the property boundaries, scale, north arrow, and the location
and nature of existing and proposed development,on the site. ,
Located on Map(s) 124"
I, J 4—"'"�7 ��✓�r` "1 �'-t'`'l hereby certify under penalty of
perjury that I am a civil engine r licensed in the State of Washington with specialized knowledge of
geotechnical/geological engineering or a geologist or engineering geologist licensed in the State of
Washington with special knowledge of the local conditions. I also certify that the Geotechnical
Report, dated I ot US I 13L-1 and entitled 4 04'r .'eeht
w x. 0� meets all the requirements of the Mason
County Resource Ordinance, Landslide Hazard Section, is complete and true, that the assessment
demonstrates conclusively that the risks posed by the landslide hazard can be mitigated through the
included geotechnical design recommendations, and that all hazards are mitigated in such a manner as
to prevent harm to property and public health and safety. (Signature and Stamp)
of
20540
0 fsj�
Page 2 of 2 Form Effective June 2008
Disclaimer: Mason County does not certify the quality of the work done in this Geotechnical Report.
Page 1 of 3
Michael MacSems - RE: Geo Review
s
From: Eric Nelson <eric(a@ainline.net>
To: Michael MacSems <mms@co.mason.wa.us>
Date: 5/19/2014 1:57 PM
Subject: RE: Geo Review
Michael,
Just got into the office and I am reviewing your questions—a few quick questions and notes:
For Question #S, the Site Preparation Plans provided with the reports has(4) sheets, C2.7, 2.8, 2.9, and 2.10
showing cross sections of the site from a number of locations which are to scale and provide an estimated
"existing" condition based on the geotechnical reports. Would this information satisfy this question?
For Question #12 (Which I think you noted as#13), the noted pages from the E3RA report dated October 25,
2013 do represent the work that would need to be done to meet the specific needs of the design assumptions
for both the building and the surrounding work areas.
As for the other two, I'll get further response on #7, but for#10, could you clarify what is meant by off-site
impacts? I could see this question with regards to the Stormwater reports since water can move off site, but as
for the geology, unless we were creating unstable soil situation above/below another site, which are not an
issue here, I do not know how there could be off site impacts.
It looks like Trish straightened out the applications and all—is there more you need on any of this?
Eric Nelson
Hainline &Associates
253-380-3947
From: Michael MacSems [mai Ito:mms@co.mason.wa.us]
Sent: Monday, May 19, 2014 10:03 AM
To: Eric Nelson
Cc: Allan Borden; Debbera Coker
Subject: Geo Review
Eric,
file:///C:/Users/mms/AppData/Local/Temp/XPgrpwise/5 3 7AODB 7Masonmai11001613462... 5/19/2014
Page 2 of 3
I've just reviewed the geo-report and have the following comments:
It seems pretty clear that the report itself was written without the checklist being used as a template
which would explain the large number of"NA"s. I accept some,but not all of the NAs. Here is what I
need addition attention paid to.
Question 5: Why wasn't a cross section of the site provided?NA is acceptable when dealing with
format issues.
Question 7: Since this project IS going to be on septic,this question has to be addressed.
Question 10: I could not find a reference to off-site impacts on pages 7-8.
Question 13: Since I am not an engineer, I might not be recognizing the answer to this question about
"structural mitigation." Does section 4.5 cover it, or is the topic covered somewhere else?
Please pass this along to Mr. Brigham. If the items that I can't find are not in to existing text, an
addendum that I can attach to the report is acceptable. PDF's are fine.
Thanks,
Michael
>>> Eric Nelson<eric(@hainline.net>5/17/2014 8:48 AM>>>
The land modification plans and associated information was submitted back during the week of April 21st
about a week before the building permit application.
I will send the questions off to Sitts & Hill, you should have responses back on Monday
Eric Nelson
Hainline &Associates
253-380-3947
From: Michael MacSems [mailto:mms(aco.mason.wa.us]
Sent: Friday, May 16, 2014 4:35 PM
To: Eric Nelson
Cc: Michael MacSems
file:///C:/Users/mms/AppData/Local/Temp/XPgrpwise/5 3 7AODB 7Masonmail 1001613462... 5/19/2014
Page 3 of 3
Subject: Stormwater Review
Eric,
I see that you sent me the geo-checklist today, but I haven't had time to review it yet. I did however
review the stormwater checklist and I do need some clarification on a few items. To put my questions
in context, I am not an engineer and I only do these reviews infrequently so it is entirely possible that I
am just not recognizing the information required by the checklist.
Please have your engineer clarify the following questions:
Checklist Section I.c: Can the engineer point me to some places where she has explained why a given
element is not applicable?
Section I.d.6: I read though sections 4.1 and 4.2 but I could not find to words "Erodibility",
"Settleability", "Permeability", "Texture" and "Soil Structure". I am assuming that those words are
implied in the contents of 4.1 and 4.2 but I would like written confirmation from the engineer.
Section I.d.11: I can not find the O&M Covenant. This document need to be recorded with the County
Auditor.
Section II.5.g: I could not find any reference to a"control/restrictor device".
II.5.m: I could not find a detail for the Construction Entrance.
II.6: I can't see where this is addressed in the documents.
II.7: I can't see where "other pollutants" is addressed on a site plan.
II.8. This loops back to I.c --please explain(or show me where it is explained) why monitoring
locations are not necessary.
Also -- FYI, I don't see in the County's permit tracking system that the land modification permit has
been submitted for this project yet.
Thanks.
Michael
file:///C:/Users/mms/AppData/Local/Temp/XPgrpwise/53 7AODB7Masonmail1001613462... 5/19/2014
Design Level
Geotechnical Engineering Report
Main Campus Improvements
North Mason High School
74 East Campus Drive
Belfair, Washington
Submitted to:
North Mason School District
c/o Erickson McGovern Architects
Attention: Wayne Lerch
101 E 26th Street, Suite 300
Tacoma, Washington 98421
Submitted by:
E3RA, Inc.
PO Box 44840
Tacoma, Washington 98448
October 25, 2013
RECEIVED
Project No. T13096
APR 2 5 2014
426 W. CEDAR ST.
TABLE OF CONTENTS
Page No.
1.0 SITE AND PROJECT DESCRIPTION .................................................................................... 1
2.0 EXPLORATORY METHODS................................................................................................... 2
2.1 Test Pit Procedures ..................................................................................................... 3
2.2 Test Hole Procedures.................................................................................................. 3
2.3 Pilot Infiltration Test Procedures.................................................................................. 3
3.0 SITE CONDITIONS ................................................................................................................. 3
3.1 Surface Conditions....................................................................................................... 3
3.2 Soil Conditions............................................................................................................. 4
3.3 Groundwater Conditions .............................................................................................. 5
3.4 Seismic Conditions ...................................................................................................... 5
3.5 Liquefaction Potential .................................................................................................. 5
3.6 Infiltration Conditions and Infiltration Rate................................................................... 5
4.0 CONCLUSIONS AND RECOMMENDATIONS....................................................................... 6
4.1 Site Preparation ........................................................................................................... 7
4.2 Spread Footings........................................................................................................... 9
4.3 Slab on Grade Floors................................................................................................. 10
4.4 Asphalt Pavement...................................................................................................... 11
4.5 Structural Fill .............................................................................................................. 12
5.0 RECOMMENDED ADDITIONAL SERVICES........................................................................ 13
6.0 CLOSURE.............................................................................................................................. 14
List of Tables
Table 1. Approximate Locations and Depths of Explorations ......................................................................2
Table 2. Laboratory Test Results for Non-Organic Onsite Soils .................................................................6
List of Figures
Figure 1. Topographic and Location Map
Figure 2. Site and Exploration Plan
APPENDIX A
Soils Classification Chart and Key to Test Data.........................................................................................A-1
Logs of Test Pits TP-1 through TP-10............................................................................................A-2...A-11
Logs of Test Holes TH-1 and TH-2..............................................................................................A-12...A-13
APPENDIX B
Laboratory Testing Results
RED'-EIVED
APR 2 5 2014
i 426 W. CEDAR ST*
PO Box 44840
Tacoma,WA 98448
253-537-9400
253-537-9401 Fax
E3RA
October 25,2013
T13096
North Mason School District
c/o Erickson McGovern Architects
101 E 26th Street, Suite 300
Tacoma,WA 98421
Attention: Wayne Lerch,Principal Architect
Subject: Design Level Geotechnical Engineering Report
Main Campus Improvements
North Mason High School
74 East Campus Drive
Belfair, Washington
Dear Mr. Lerch:
E3RA is pleased to submit this report describing the results of our design level geotechnical engineering
evaluation for the improvements planned at North Mason School District Main Campus which is located at 74
East Campus Drive in Belfair,Washington.
This report has been prepared for the exclusive use of the North Mason School District,and their consultants,
for specific application to this project,in accordance with generally accepted geotechnical engineering practice.
1.0 SITE AND PROJECT DESCRIPTION
The project site is a roughly rectangular area located east of SR 3 and south of North Mason School Road. It
encompasses more than 30 acres,as shown on the enclosed Topographic and Location Map(Figure 1).
Currently,the south-central part of the Main Campus is occupied by a high school;a middle school occupies
the north-central part of the Main Campus;athletic fields and tennis courts occupy the east third and northwest
comer of the site;a gymnasium occupies the central part of the site;and asphalt pavements,administrative and
maintenance buildings, other structures, lawns,and woodlands occupy the remainder of the site.
Plans call for the construction of a new high school on the east-central part of the site, which is currently
occupied by an athletic field. The existing middle school will be removed,and the existing high school will be
converted into a new middle school. Additionally,a new stadium/athletic field will be built on the northwest
corner of the site;a new athletic field will be built on the northeast corner of the site;and new pavements will
be constructed to accommodate the planned improvements.
Storm water will be disposed of on site and a septic system is planned for the northeast part of the site.
October 25, 2013 E3RA, Inc.
T13096/North Mason High School Design Level Geotechnical Engineering Report
2.0 EXPLORATORY METHODS
We previously explored surface and subsurface conditions at the project site on September 30 and October 1,
2013. Our exploration and evaluation program comprised the following elements:
• Surface reconnaissance of the site;
• Ten test pits (designated TP-1 through TP-10), advanced on September 30, 2013;
• Two test holes(designated TH-1 and TH-2), advanced on October 1, 2013;
• Five grain-size analyses performed on samples collected from our test pit explorations;
• One Pilot Infiltration Test, conducted on September 30, 2013 in one of our test pit
explorations; and
• A review of published geologic and seismologic maps and literature.
Table 1 summarizes the approximate functional locations and termination depths of our subsurface
explorations, and Figure 2 depicts their approximate relative locations. The following sections describe the
procedures used for excavation of test pits and test holes, and Pilot Infiltration Test Procedures.
TABLE 1
APPROXIMATE LOCATIONS AND DEPTHS OF EXPLORATIONS
Termination
Exploration Functional Location Depth
(feet)
TP-1 North of planned new school 14
TP-2 East of existing middle school 12'/z
TP-3 South of existing middle school 14'/z
TP-4 Northwest site 15
TP-5* South of southwest corner planned new school 15
TP-6 West edge planned new school 6
TP-7 North part planned septic system 7
TP-8 South part planned new septic system 8
TP-9 Southeast of planned new school 14'/z
TP-10 South-central site, in footprint of possible storm pond 10
TH-1 North edge planned new school 4'/2
TH-2 I South edge of planned new school 6
*Includes Pilot Infiltration Test
The specific number and locations of our explorations were selected in relation to the existing site features,
under the constraints of surface access,underground utility conflicts, and budget considerations.
It should be realized that the explorations performed and utilized for this evaluation reveal subsurface
conditions only at discrete locations across the project site and that actual conditions in other areas could vary.
Furthermore, the nature and extent of any such variations would not become evident until additional
explorations are performed or until construction activities have begun. If significant variations are observed
at that time,we may need to modify our conclusions and recommendations contained in this report to reflect
the actual site conditions.
2
October 25, 2013 PRA, Inc.
T13096/North Mason High School Design Level Geotechnical Engineering Report
2.1 Test Pit Procedures
Our exploratory test pits were excavated with a steel-tracked excavator by an owner-operator under contract to
E3RA. An engineering geologist from our firm observed the test pit excavations,collected soil samples,and
logged the subsurface conditions.
The enclosed test pit logs indicate the vertical sequence of soils and materials encountered in each test pit,
based on our field classifications. Where a soil contact was observed to be gradational or undulating,our logs
indicate the average contact depth. We estimated the relative density and consistency of the in-situ soils by
means of the excavation characteristics and the stability of the test pit sidewalls. Our logs also indicate the
approximate depths of any sidewall caving or groundwater seepage observed in the test pits. The soils were
classified visually in general accordance with the system described in Figure A-1,which includes a key to the
exploration logs. Summary logs of the explorations are included as Figures A-2 through A-13.
2_2 Test Hole Procedures
Our exploratory test holes were advanced with a shovel, a post-hole digger, iron bar, and a 3-inch-diameter
hand auger operated by an E3RA geologist,who logged the subsurface conditions. After each test hole was
completed,we backfilled it with excavated soils and tamped the surface.
The enclosed test hole logs describe the vertical sequence of soils and materials encountered in each test hole,
based primarily on our field classifications and supported by our subsequent laboratory examination and
testing. Where a soil contact was observed to be gradational or undulating, our logs indicate the average
contact depth. Our logs also indicate the approximate depth of any sidewall caving or groundwater seepage
observed in the test holes.
2.3 Pilot Infiltration Test Procedures
Our Pilot Infiltration Test was performed in general accordance with the procedures listed in the current DOE
Stormwater Management Manual.
A large test pit was excavated down to approximate facility invert elevation(5%feet)so that the lowermost
10 inches or so of the excavation was steep-sided,while the upper 4'/2 feet or so of the excavation was graded
back to a less than 2H:1 V inclination.
The floor of the test pit was measured, a stadia rod was placed to measure water depth within the pit, and a
water hose was attached to the closest fire hydrant and water pumped into the excavation. An in-line flow
meter measured the flow rate in gallons per minute and kept track of the total volume of water pumped,and
rate and volume pumped were recorded at 5 to 15 minute intervals. Water was dispersed at the floor of the test
pit through a 2 inch diameter,20 slot PVC pipe,which served to dissipate flow energy of the water.
3.0 SITE CONDITIONS
The following sections present our observations, measurements, findings, and interpretations regarding,
surface, soil, groundwater, seismic,liquefaction,and infiltration conditions.
3.1 Surface Conditions
The northeast, highest part of the site is an upland that extends off site to the north, northeast, and east.
Original site topography likely descended gently from the northeast upland part of the site toward the west,
southwest,and south. Current site grades generally conform to the original direction of topographic descent,
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but have been over-steepened and leveled locally during site development. All site slopes,including those that
have been steepened during development,appear stable.
No hydrologic features were observed on site, with the exception of puddles and pools that formed during
heavy recent rainfall.
Vegetation on the site consists of grass lawns and grass ball fields,ornamental trees and shrubbery. Smaller
areas of fir woodlands grow on the northeast,northwest,east-central,and south parts of the site.
As indicated in our introductory paragraphs,the site is occupied by school,administrative,maintenance,paved
areas, and other structures.
3.2 Soil Conditions
Our onsite explorations indicate that native soils vary somewhat.
Deep gravelly sand and sandy gravel were observed in test pits TP-1,TP-4 and TP-9,which were located in a
woodland north of the planned school (TP-1), the northwest part of the site (TP-4), and southeast of the
planned school(TP-9),respectively. Relatively clean sand was observed at approximate storm water facility
invert elevation in test pit TP-5, where a pilot infiltration test was conducted south of the planned school.
However, when TP-5 was excavated down after the pilot infiltration test was completed, a silty lens was
encountered at a depth of about 8 feet;2'/z feet below the elevation at which the infiltration test was run.
In the area of the planned septic system,in test pits TP-7 and TP-8,we observed silty sand with trace silt and
gravel with trace silt in the upper 4 to 5 feet of soil. Hard, impermeable silty soils were observed below a
depth of 4 to 5 feet in both test pits,however.
In test pit TP-2 (southeast of middle school),where storm water infiltration is proposed, a surface mantle of
fill,which extended down to a depth of 2'h feet,was underlain by layers of silty, gravelly sand; silty sand;
sandy gravel with silty interbeds;and clean gravelly sand. In test pit TP-3 located west of the middle school
and also where infiltration is proposed,we observed 9 feet of fill,underlain by clean gravelly sand. In test pit
TP-10,located on the south-central part of the site,where a small storm water pond is proposed,we observed
4'/2 feet of fill overlying, to a depth of 7 feet, clean sand. At a depth of 7 feet, and extending down to the
termination of the exploration at a depth of 10 feet, we encountered dense glacial till comprised of silty,
gravelly sand.
Test pits TP-5 and TP-6 and test holes TH-1 and TH-2 were excavated in the vicinity of the planned new high
school. Organic-rich fill was observed to a depth of 5 feet on the west side of the school(TP-6),2'/2 feet near
the southwest corner of the school(TP-5),and 3 feet on the south edge of the school(TH-2). Our exploration
on the north edge of the school, TH-1, encountered 8 inches of sod and topsoil overlying 2 feet of medium
dense, organic-free fill comprised of sand with some silt. Medium dense, native sand, which varied in silt
content, was encountered immediately under the fill layer in all of our explorations in the vicinity of the
planned school.
The enclosed exploration logs (Appendix A)provide a detailed description of the soil strata encountered in
our subsurface explorations.
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3.3 Groundwater Conditions
At the time of our reconnaissance and subsurface explorations (September 30 and October 1, 2013), we
encountered slow seepage at a depth of 12 feet in test pit TP4,located on the northwest part of the site and at a
depth of 5 to 6 feet in test pit TP-7,located on the north part of the planned septic system. We did not observe
seepage in any of our other test pit explorations,which extended down to depths of up to 14%2 feet.
3.4 Seismic Conditions
Based on our analysis of subsurface exploration logs and our review of published geologic maps,we interpret
the onsite soil conditions to generally correspond with site class D,as defined by Table 1613.5.2 of the 2012
International Building Code(IBC).
Using 2012 IBC information on the USGS Design Summary Report website,Risk Category I/11/III seismic
parameters for the site are as follows:
S5= 1.437 g S,,, = 1.437 g SDs=0.958 g
S,=0.576 g Sµ,=0.863 g SD1=0.576 g
Using the 2012 IBC information,MCER Response Spectrum Graph on the USGS Design Summary Report
website,Risk Category 1/11/111,Sa at a period of 0.2 seconds is 1.45 g and Sa at a period of 1.0 seconds is 0.95g.
The Design Response Spectrum Graph from the same website, using the same IBC information and Risk
Category, Sa at a period of 0.2 seconds is 0.95 g and Sa at a period of 1.0 seconds is 0.60 g.
3.5 Liquefaction Potential
Liquefaction is a sudden increase in pore water pressure and a sudden loss of soil shear strength caused by
shear strains,as could result from an earthquake. Research has shown that saturated, loose, fine to medium
sands with a fines(silt and clay)content less than about 20 percent are most susceptible to liquefaction. Our
onsite subsurface explorations did not reveal saturated (or potentially saturated), loose, silty sand layers or
lenses.
3.6 Infiltration Conditions and Infiltration Rate
There is some variability across the site. Based on our field observations and grain size analyses(presented in
Table 2),soils within TP-1 (north of planned school,in woods),TP-4(northwest site),and TP-9(southeast of
planned school) have the most rapidly permeable soils. Infiltration conditions within TP-5 (where the
infiltration test was performed) are good, and infiltration conditions in test pits TP-2 (southeast of existing
middle school), TP-3 (west of existing middle school) and TP-10 (south-central site, within footprint of
proposed storm water pond)are not good.
The results of our soil grain size analyses are presented below, and the attached Soil Gradation Graphs
(Appendix B)display the grain-size distribution of the samples tested.
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TABLE 2
LABORATORY TEST RESULTS FOR NON-ORGANIC ONSITE SOILS
Soil Sample, Depth %Coarse %Fine %Coarse %Medium %Fine %Fines Dio
Gravel Gravel Sand Sand Sand
TP-1, S-1,5'/2 feet 16 28 7 11 37 2 0.17
TP-4, S-1,5'/2 feet 16 47 13 13 11 1 0.37
TP-5, S-1,5'/z feet 0 7 5 16 68 4 FO.11
TP-9,S-1,5'/z feet 4 32 22 35 5 2 0.52
TP-10, S-2, 8 feet 25 1 8 1 6 1 11 1 25 15 --
Infiltration Test Results
Test pit TP-5 was excavated down to a depth of 5'/z feet,and,a steady-state flow of 16.5 inches per hour,with
a head of 8 inches,was eventually achieved. Water was pumped into the test pit at the steady-state flow for a
period of about 3 hours,during which a head of about 8 inches was maintained. Pumping was then terminated,
and the 8 inch head within the pit fell at an average rate of 14.5 inches per hour.
Design Infiltration Rate
We determined the Design Infiltration Rate using Table 3.3.1 in the D.O.E.Manual,Volume 111,pages 3-81
and 3-82,which provides correction factors for Pilot Infiltration Testing. We used an average of the steady-
state flow rate(16.5 inches per hour)and the falling head rate(14.5 inches per hour),which is 15.5 inches per
hour,as a basis for calculating the Design Rate. Three Partial Correction factors are used in the DOE Manual:
one for Degree of Influent Control (CF;); one for Site Variability (CF,,); and one for small-scale Pilot
Infiltration Testing (CFt). Table 3.3.1 recommends 0.50 the Partial Correction Factor for small-scale PIT
(CF); 0.90 for Degree of Influent Control (CF;), and 0.33 to 1.0 for Site Variability (CFI). The Total
Correction Factor is calculated by multiplying the three Partial Correction Factors together. We used a value of
1.00 for Site Variability(CF,,),because a silt lens was observed a few feet under the test area,and likely slowed
the rate of infiltration in the test area significantly. This value adequately addresses site variability, in our
opinion.
Multiplied together,the Total Correction Factor for the test area is 0.45 and the calculated Design Infiltration
Rate is 7 inches per hour.
It is our opinion that,based on field observations and grain size analyses, the Design Infiltration Rate cited
above can also be applied to the vicinities of test pits TP-1,TP-4, and TP-9.
Once the location of the infiltration facility is decided,further subsurface explorations should be conducted
within the facility footprint in order to confirm that uniform soil conditions exist there. It is best that further
testing be conducted in the late fall or early winter when groundwater is at a seasonal high.
4.0 CONCLUSIONS AND RECOMMENDATIONS
Plans call for the construction of a new school building,new pavements,and for the onsite infiltration of storm
water. We offer these recommendations:
• Feasibility: Based on our field explorations,research,and analyses,the proposed structure,
pavements, and a storm water infiltration facility appear feasible from a geotechnical
standpoint.
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• Foundation Options: We recommend conventional spread footings that bear on medium
dense or denser native soils or on properly compacted structural fill that extends down to
medium dense or denser native soil. We observed organic-rich fill and topsoil, extending
down 1 to 5 feet in the vicinity of the new school. It will have to be removed as part of
footing subgrade preparation. Specific recommendations for Spread Footings and Structural
Fill are provided in Section 4.
• Floor Options: As with the recommendations for foundations, organic-rich soils should be
removed as part of the subgrade preparation process for the construction of slab floors,and
floor sections should bear on medium dense or denser native soils or on properly compacted
structural fill that extends down to medium dense or denser native soil. Recommendations for
slab-on-grade floors are provided in Section 4.
• Pavement Sections: After removal of any organics underlying pavements,we recommend a
conventional pavement section comprised of an asphalt concrete pavement over a crushed
rock base course over a properly prepared(compacted)subgrade or a granular subbase.
All soil subgrades should be thoroughly compacted,then proof-rolled with a loaded dump
truck or heavy compactor. Any localized zones of yielding subgrade disclosed during this
proof-rolling operation should be overexcavated to a depth of 12 inches and replaced with a
suitable structural fill material.
• Infiltration Conditions: We recommend a Design Infiltration Rate of 7 inches per hour for
storm water facilities located in the vicinity of test pits TP-1,TP-4,TP-5,and TP-9. We do
not recommend storm water infiltration in the vicinity of test pits TP-2,TP-3,TP-10,or near
the planned septic drain field.
Once the location of the infiltration facility is decided,further subsurface explorations should
be conducted within the facility footprint in order to confirm uniform soil conditions there. It
is best that further testing be conducted in the late fall or early winter when groundwater is at
a seasonal high.
The following sections of this report present our specific geotechnical conclusions and recommendations
concerning site preparation,spread footings,slab-on-grade floors,asphalt pavement,and structural fill. The
Washington State Department of Transportation(WSDOT)Standard Specifications and Standard Plans cited
herein refer to WSDOT publications M41-10, Standard Specifications for Road, Bridge, and Municipal
Construction,and M21-01,Standard Plans for Road, Bridge, and Municipal Construction,respectively.
4_1 Site Preparation
Preparation of the project site should involve erosion control,temporary drainage,clearing,stripping,cutting,
filling, excavations, and subgrade compaction.
Erosion Control: Before new construction begins,an appropriate erosion control system should be installed.
This system should collect and filter all surface water runoff through silt fencing. We anticipate a system of
berms and drainage ditches around construction areas will provide an adequate collection system. Silt
fencing fabric should meet the requirements of WSDOT Standard Specification 9-33.2 Table 3. In addition,
silt fencing should embed a minimum of 6 inches below existing grade. An erosion control system requires
occasional observation and maintenance. Specifically,holes in the filter and areas where the filter has shifted
above ground surface should be replaced or repaired as soon as they are identified.
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Temporary Drainage: We recommend intercepting and diverting any potential sources of surface or
near-surface water within the construction zones before stripping begins. Because the selection of an
appropriate drainage system will depend on the water quantity, season, weather conditions, construction
sequence,and contractor's methods,final decisions regarding drainage systems are best made in the field at the
time of construction. Based on our current understanding of the construction plans, surface and subsurface
conditions,we anticipate that curbs,berms,or ditches placed around the work areas will adequately intercept
surface water runoff.
Clearing and Stripping: After surface and near-surface water sources have been controlled, sod and topsoil,
and root-rich soil should be stripped from the site. Our explorations indicate that the sod/topsoil layer varies
greatly over the site and is only a few inches thick in the vicinity of the planned septic system and can be a foot
thick elsewhere. Additionally, thick organic rich fill, which will have to be removed from structural areas,
overlies some of the site. Stripping is best performed during a period of dry weather.
Site Excavations: Based on our explorations,we expect that excavations will encounter medium dense sandy
soil which can be easily excavated using standard excavation equipment.
Dewaterin : Our site explorations encountered groundwater only near the planned septic system and at a depth
of 12 feet on the northwest part of the site. If groundwater is encountered,we anticipate that an internal system
of ditches, sumpholes, and pumps will be adequate to temporarily dewater excavations.
Temporary Cut Slopes: All temporary soil slopes associated with site cutting or excavations should be
adequately inclined to prevent sloughing and collapse. Temporary cut slopes in site soils should be no steeper
than 1'/2H:IV, and should conform to Washington Industrial Safety and Health Act(WISHA)regulations.
Subgrade Compaction: Exposed subgrades for the retaining wall should be compacted to a firm,unyielding
state before new concrete or fill soils are placed. Any localized zones of looser granular soils observed within
a subgrade should be compacted to a density commensurate with the surrounding soils. In contrast, any
organic, soft, or pumping soils observed within a subgrade should be overexcavated and replaced with a
suitable structural fill material.
Site Filling: Our conclusions regarding the reuse of onsite soils and our comments regarding wet-weather
filling are presented subsequently. Regardless of soil type,all fill should be placed and compacted according
to our recommendations presented in the Structural Fill section of this report. Specifically,building pad fill
soil should be compacted to a uniform density of at least 95 percent(based on ASTM:D-1557).
Onsite Soils: We offer the following evaluation of these onsite soils in relation to potential use as structural
fill:
• Surficial Organic Soil and Organic-Rich Fill Soils: Where encountered, surficial organic
soils, like duff, topsoil, root-rich soil, and organic-rich fill soils are not suitable for use as
structural fill under any circumstances, due to high organic content. Consequently, this
material can be used only for non-structural purposes,such as in landscaping areas.
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• Silty. Gravelly Sand: Sil& Sand: Underlying the surface topsoil/sod/duff layer, a foot to
2 foot thick layer of silty, gravelly sand; silty sand; and/or sand with some silt is often
encountered on site. These soils are moisture sensitive and will be difficult to reuse during
wet weather conditions.
• Gravelly Sand and Sandy Gravel and Sand with Trace Silt: Within a few feet of the surface
in the vicinity of TP-1,TP-4,TP-5,TP-9,and TH-1,and in isolated layers in TP-2,TP-3,and
TP-10, we observed sandy or gravelly soil that contained few fines. This soil is relatively
insensitive to moisture content variations and can be reused year-round,provided particles
larger than 6 inches are removed.
• Glacial Till-like Soils: Although not a prevalent soil on site,glacial till-like soils,comprised
of gravelly,sandy silt and silty,gravelly sand,were observed at depths of 4%2 to 5 feet in the
vicinity of the planned septic system(TP-7 and TP-8)and near the planned storm water pond
(TP-10) on the south-central part of the site. This soil is moisture sensitive and will be
difficult to reuse during wet weather conditions.
Permanent Slopes: All permanent cut slopes and fill slopes should be adequately inclined to reduce long-term
raveling,sloughing,and erosion. We generally recommend that no permanent slopes be steeper than 2H:1 V.
For all soil types, the use of flatter slopes (such as 2'/2H:IV) would further reduce long-term erosion and
facilitate revegetation.
Slope Protection: We recommend that a permanent berm,swale,or curb be constructed along the top edge of
all permanent slopes to intercept surface flow. Also,a hardy vegetative groundcover should be established as
soon as feasible,to further protect the slopes from runoff water erosion. Alternatively,permanent slopes could
be armored with quarry spalls or a geosynthetic erosion mat.
4.2 Spread Footings
In our opinion,conventional spread footings will provide adequate support for the new school building if the
subgrades are properly prepared.
Footing Deaths and Widths: For frost and erosion protection,the bases of all exterior footings should bear at
least 18 inches below adjacent outside grades,whereas the bases of interior footings need bear only 12 inches
below the surrounding slab surface level. To reduce post-construction settlements, continuous (wall) and
isolated(column)footings should be at least 18 and 24 inches wide,respectively.
Bearing Sub grades: Footings should bear on medium dense or denser,undisturbed native soils which have
been stripped of surficial organic soils,or on properly compacted structural fill which bears on the soils just
described. Organic-rich fill,which can extend to a depth of 5 feet,underlies part of the building footprint. It
will have to be over-excavated and replaced.
In general,before footing concrete is placed, any localized zones of loose soils exposed across the footing
subgrades should be compacted to a firm,unyielding condition, and any localized zones of soft, organic, or
debris-laden soils should be overexcavated and replaced with suitable structural fill.
Lateral Overexcavations: Because foundation stresses are transferred outward as well as downward into the
bearing soils,all structural fill placed under footings,should extend horizontally outward from the edge of each
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footing. This horizontal distance should be equal to the depth of placed fill. Therefore placed fill that extends
24 inches below the footing base should also extend 24 inches outward from the footing edges.
Subarade Observation: All footing subgrades should consist of firm,unyielding,native soils, or structural fill
materials that have been compacted to a density of at least 95 percent(based on ASTM:D-1557). Footings
should never be cast atop loose, soft, or frozen soil, slough, debris, existing uncontrolled fill, or surfaces
covered by standing water.
Bearing Pressures: In our opinion,for static loading,footings that bear on properly prepared subgrades can be
designed for a maximum allowable soil bearing pressure of 2,000 psf. A one-third increase in allowable soil
bearing capacity may be used for short-term loads created by seismic or wind related activities.
Footing Settlements: Assuming that structural fill soils are compacted to a medium dense or denser state,we
estimate that total post-construction`ttleme f properly designed footings bearing on properly prepared
subgrades will not exceed 1 inch. Di eren al settlements for comparably loaded elements may approach
one-half of the actual total settlement over horizontal distances of approximately 50 feet.
Footing Backfill: To provide erosion protection and lateral load resistance, we recommend that all footing
excavations be backfilled on both sides of the footings and stemwalls after the concrete has cured. Either
imported structural fill or non-organic onsite soils can be used for this purpose,contingent on suitable moisture
content at the time of placement. Regardless of soil type, all footing backfill soil should be compacted to a
density of at least 90 percent(based on ASTM:D-1557).
Lateral Resistance: Footings that have been properly backfilled as recommended above will resist lateral
movements by means of passive earth pressure and base friction. We recommend using an allowable passive
earth pressure of 250 psf for and an allowable base friction coefficient of 0.35 for site soils.
4.3 Slab-On-Grade Floors
In our opinion, soil-supported slab-on-grade floors can be used in structures if the subgrades are properly
prepared. We offer the following comments and recommendations concerning slab-on-grade floors.
Floor Subbase: Generally, structural fill subbases do not appear to be needed under soil-supported
slab-on-grade floors,but stripping of sod and topsoil and localized over-excavation of organic-rich fill will be
necessary. The final decision regarding the need for subbases should be based on actual subgrade conditions
observed at the time of construction. Surface compaction of slab subgrades is recommended.
If a subbase is needed, all subbase fill should be compacted to a density of at least 95 percent (based on
ASTM:D-1557).
Capillary Break and Vapor Barrier: To retard the upward wicking of moisture beneath the floor slab, we
recommend that a capillary break be placed over the subgrade. Ideally,this capillary break would consist of a
4-inch-thick layer of pea gravel or other clean, uniform, well-rounded gravel, such as"Gravel Backfill for
Drains"per WSDOT Standard Specification 9-03.12(4),but clean angular gravel can be used if it adequately
prevents capillary wicking. In addition,a layer of plastic sheeting(such as Crosstuff,Visqueen,or Moistop)
should be placed over the capillary break to serve as a vapor barrier. During subsequent casting of the concrete
slab,the contractor should exercise care to avoid puncturing this vapor barrier.
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4.4 Asphalt Pavement
Since asphalt pavements will be used for the driveways,bus loops,and parking areas,we offer the following
comments and recommendations for pavement design and construction.
Subgrade Preparation: After removal of any surficial sod,topsoil,or organic-rich fill,all soil subgrades should
be thoroughly compacted, then proof-rolled with a loaded dump truck or heavy compactor. Any localized
zones of yielding subgrade disclosed during this proof-rolling operation should be over excavated to a
maximum depth of 12 inches and replaced with a suitable structural fill material. All structural fill should be
compacted according to our recommendations given in the Structural Fill section. Specifically,the upper 2 feet
of soils underlying pavement section should be compacted to at least 95 percent(based on ASTM D-1557),
and all soils below 2 feet should be compacted to at least 90 percent.
Pavement Materials: For the base course, we recommend using imported crushed rock, such as "Crushed
Surfacing Top Course" per WSDOT Standard Specification 9-03.9(3). If a subbase course is needed, we
recommend using imported, clean, well-graded sand and gravel such as "Ballast' or"Gravel Borrow"per
WSDOT Standard Specifications 9-03.9(1)and 9-03.14,respectively.
Conventional Asphalt Sections: A conventional pavement section typically comprises an asphalt concrete
pavement over a crushed rock base course. We recommend using the following conventional pavement
sections:
Minimum Thickness
Pavement Course Parking Areas High Traffic Areas Bus Loops
Asphalt Concrete Pavement 2 inches 3 inches 4 inches
Crushed Rock Base 4 inches 6 inches 6 inches
Granular Fill Subbase(if needed) 6 inches 12 inches 12 inches
Compaction and Observation: All subbase and base course material should be compacted to at least 95 percent
of the Modified Proctor maximum dry density(ASTM D-1557),and all asphalt concrete should be compacted
to at least 92 percent of the Rice value (ASTM D-2041). We recommend that an E3RA representative be
retained to observe the compaction of each course before any overlying layer is placed. For the subbase and
pavement course, compaction is best observed by means of frequent density testing. For the base course,
methodology observations and hand-probing are more appropriate than density testing.
Pavement Life and Maintenance: No asphalt pavement is maintenance-free. The above described pavement
sections present our minimum recommendations for an average level of performance during a 20-year design
life;therefore,an average level of maintenance will likely be required. Furthermore,a 20-year pavement life
typically assumes that an overlay will be placed after about 10 years. Thicker asphalt and/or thicker base and
subbase courses would offer better long-term performance, but would cost more initially; thinner courses
would be more susceptible to"alligator"cracking and other failure modes. As such,pavement design can be
considered a compromise between a high initial cost and low maintenance costs versus a low initial cost and
higher maintenance costs.
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4.5 Structural Fill
The term"structural fill"refers to any material placed under foundations,retaining walls,slab-on-grade floors,
sidewalks,pavements,and other structures. Our comments,conclusions,and recommendations concerning
structural fill are presented in the following paragraphs.
Materials: Typical structural fill materials include clean sand, gravel,pea gravel,washed rock,crushed rock,
well-graded mixtures of sand and gravel(commonly called"gravel borrow"or"pit-run"),and miscellaneous
mixtures of silt,sand,and gravel. Recycled asphalt,concrete,and glass,which are derived from pulverizing
the parent materials,are also potentially useful as structural fill in certain applications. Soils used for structural
fill should not contain any organic matter or debris,nor any individual particles greater than about 6 inches in
diameter. Because pervious pavement may be planned, import fill should be granular and well draining.
Fill Placement: Clean sand, gravel, crushed rock, soil mixtures, and recycled materials should be placed in
horizontal lifts not exceeding 8 inches in loose thickness,and each lift should be thoroughly compacted with a
mechanical compactor.
Compaction Criteria: Using the Modified Proctor test(ASTM:D-1557) as a standard, we recommend that
structural fill used for various onsite applications be compacted to the following minimum densities:
Minimum
Fill Application
Compaction
Footing subgrade and bearing pad 95 percent
Foundation backfill 90 percent
Slab-on-grade floor subgrade and subbase 95 percent
Asphalt pavement base 95 percent
Asphalt pavement subgrade (upper 2 feet) 95 percent
Asphalt pavement subgrade(below 2 feet) 90 percent
Subgrade Observation and Compaction Testing: Regardless of material or location,all structural fill should be
placed over firm,unyielding subgrades prepared in accordance with the Site Preparation section ofthis report.
The condition of all subgrades should be observed by geotechnical personnel before filling or construction
begins. Also,fill soil compaction should be verified by means of in-place density tests performed during fill
placement so that adequacy of soil compaction efforts may be evaluated as earthwork progresses.
Soil Moisture Considerations: The suitability of soils used for structural fill depends primarily on their
grain-size distribution and moisture content when they are placed. As the "fines" content(that soil fraction
passing the U.S.No.200 Sieve)increases,soils become more sensitive to small changes in moisture content.
Soils containing more than about 5 percent fines (by weight) cannot be consistently compacted to a firm,
unyielding condition when the moisture content is more than 2 percentage points above or below optimum.
For fill placement during wet-weather site work,we recommend using"clean" fill,which refers to soils that
have a fines content of 5 percent or less(by weight)based on the soil fraction passing the U.S.No. 4 Sieve.
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5.0 RECOMMENDED ADDITIONAL SERVICES
Because the future performance and integrity of the structural elements will depend largely on proper site
preparation, drainage, fill placement, and construction procedures, monitoring and testing by experienced
geotechnical personnel should be considered an integral part of the construction process. Consequently,we
recommend that E3RA be retained to provide the following post-report services:
• Conduct additional test pit explorations,during the wet season,in the vicinity the infiltration
facility,once the facility location has been decided;
• Review all construction plans and specifications to verify that our design criteria presented in
this report have been properly integrated into the design;
• Prepare a letter summarizing all review comments(if required);
• Check all completed subgrades for footings and slab-on-grade floors before concrete is
poured, in order to verify their bearing capacity;and
• Prepare a post-construction letter summarizing all field observations, inspections, and test
results(if required).
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6.0 CLOSURE
The conclusions and recommendations presented in this report are based,in part,on the explorations that we
observed for this study;therefore,if variations in the subgrade conditions are observed at a later time,we may
need to modify this report to reflect those changes. Also,because the future performance and integrity of the
project elements depend largely on proper initial site preparation, drainage, and construction procedures,
monitoring and testing by experienced geotechnical personnel should be considered an integral part of the
construction process. E3RA is available to provide geotechnical monitoring of soils throughout construction.
We appreciate the opportunity to be of service on this project. If you have any questions regarding this report
or any aspects of the project,please feel free to contact our office.
Sincerely,
E3RA,Inc. 0# W as ti5 BC
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TEST PIT LOCATIONS _ NOTE:
8 BOUNDARY AND TOPOGRAPHY ARE BASED ON
MAPPING PROVIDED TO E3RA BY ERICKSON MCGOVERN
TEST HOLE LOCATION TP-7 TP-8 m m AND OBSERVATIONS MADE IN THE FIELD. THE INFORMATION
TH-1 8 8 SHOWN DOES NOT CONSTITUTE A FIELD SURVEY BY E3RA.
W
13 TP-9
3
� l
TP-1 '"
NEE TH-1 1
M IUK7 AlODLECJ1001,1,U TH-2j
� � I III ,
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TP-5
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TP-2 AXMi
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AM� TP-10mom Flom
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��.�« \\ am PROJECT: North Mason High School
-,TP-4 ( E 3RA Inc. Campus Improvements
MEN\ °^ SHEET TITLE: Site and Exploration Plan
PO Box 44840
C" Tacoma, WA 98448 DESIGNER: CRL JOB NO.T13096
(A 031NCiAD.Vi3i1tKAN
253-537-9400 DRAWN BY: CRL SCALE: As Shown
253-537-9401 fax
WWW.e3ra.com CHECKED BY: JEB FIGURE:2
DATE: Oct. 10, 2013 FILE: T13096.dwg
APPENDIX A
SOILS CLASSIFICATION CHART AND
KEY TO TEST DATA
LOG OF TEST PITS AND TEST HOLES
MAJOR DIVISIONS TYPICAL NAMES
CLEAN GRAVELS GW WELL GRADED GRAVELS,GRAVEL-SAND MIXTURES
GRAVELS WITH LITTLE OR
MORE THAN HALF NO FINES GP .o: o POORLY GRADED GRAVELS,GRAVEL-SAND MIXTURES
o' D:
COARSE FRACTION
`" ' GMR
SILTY GRAVELS,POORLY GRADED GRAVEL-SAND-SILT
IS LARGER THAN GRAVELS WITH MIXTURES
0 oo NO.4 SIEVE OVER 15%FINES
uj cv CLAYEY GRAVELS,POORLY GRADED GRAVEL-SAND-CLAY
Qz A GC MIXTURES
Wm CLEAN SANDS SW WELL GRADED SANDS,GRAVELLY SANDS
E SANDS WITH LITTLE
ap 0 OR NO FINES SP POORLY GRADED SANDS,GRAVELLY SANDS
MORE THAN HALF
COARSE FRACTION
IS SMALLER THAN SM SILTY SANDS,POOORLY GRADED SAND-SILT MIXTURES
SANDS WITH
N0.4 SIEVE
OVER 15%FINES
SC CLAYEY SANDS,POORLY GRADED SAND-CLAY MIXTURES
INORGANIC SILTS AND VERY FINE SANDS,ROCK FLOUR,
ML
SC
OR CLAYEY FINE SANDS,OR CLAYEY SILTS WITH
SILTS AND CLAYS SLIGHT PLASTICITY
INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY,
CL GRAVELLY CLAYS,SANDY CLAYS,SILTY CLAYS,
i U) LIQUID LIMIT LESS THAN 50 LEAN CLAYS
0
O o —_
o C GL ORGANIC CLAYS AND ORGANIC SILTY CLAYS OF LOW
w = PLASTICITY
z w —
= INORGANIC SILTS,MICACEOUS OR DIATOMACIOUS FINE
(9 m MH SANDY OR SILTY SOILS,ELASTIC SILTS
Z a) SILTS AND CLAYS
LL o CH INORGANIC CLAYS OF HIGH PLASTICITY,FAT CLAYS
� LIQUID LIMIT GREATER THAN 50
OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY,
ORGANIC SILTS
HIGHLY ORGANIC SOILS Pt PEAT AND OTHER HIGHLY ORGANIC SOILS
8 Modified California RV R-Value
® Split Spoon SA Sieve Analysis
Pushed Shelby Tube SW Swell Test
m Auger Cuttings TC Cyclic Triaxial
® Grab Sample TX Unconsolidated Undrained Triaxial
Sample Attempt with No Recovery TV Torvane Shear
CA Chemical Analysis UC Unconfined Compression
CN Consolidation (1.2) (Shear Strength,ksf)
CP Compaction WA Wash Analysis
DS Direct Shear (20) (with%Passing No.200 Sieve)
o PM Permeability Water Level at Time of Drilling
PP Pocket Penetrometer 1 Water Level after Drilling(with date measured)
d
c�
m
D SOIL CLASSIFICATION CHART AND KEY TO TEST DATA
z
E3RA
Z Figure A-1
Z
Z
a
0
J
E3RA, Inc. TEST PIT NUMBER TP-1
PO Box 44840
E3M, Inc. Tacoma,WA 98448 PAGE 1 1
Telephone: 253-537-9400 Figuree A-2
Fax 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High Schad Main Campus Improvements
PROJECT NUMBER T13096 PROJECT LOCATION Belfair,Washington
DATE STARTED 9/30/13 COMPLETED 9/30/13 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION ---
NOTES In woods,north of planned high school AFTER EXCAVATION ---
W c
_ w cn =
ww ED tu o_p MATERIAL DESCRIPTION
o_
a M z w v (0
C9 CO W
a 14 inches Forest Duff and root-rich Topsoil
U)
111.2
i=
(SM)Light brown silty sand with some gravel(medium dense,moist)
SM
U
Z
3.0
(SP)Gray gravelly sand with trace silt(medium dense,moist)(Recessional Glacial Outwash)
x
z
0
a
Z
z 5
> GB
oy S-1 6
c
U
Z
O
U
Y
U
lY
w
m
rn
0
M
F
N
SIP
LL
m
M
O
<� 10
S
W
Z
Q
i
0
N
O
a'
14.0
LL No caving observed
No groundwater seepage observed
0
The depths on the test pit logs are based on an average of measurements across the test pit and should be
considered accurate to 0.5 foot.
m Bottom of test pit at 14.0 feet.
qJ
W
Z
W
O
LL
0
}
a
O
U
E3RA,Inc. TEST PIT NUMBER TP-2
PO Box44840 PAGE 1 OF 1
E3RA, If1C. Tacoma,WA 98448 Figure A-3
Telephone: 253-537-9400
Fax: 253-537-9401
CLIENT Erickson McGovem Architects PROJECT NAME North Mason High School Main Campus Improvements
PROJECT NUMBER T13096 PROJECT LOCATION Belfair,Washington
DATE STARTED 9/30/13 COMPLETED 9/30/13 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION --
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION _-
NOTES Southeast comer of middle school AFTER EXCAVATION ---
W c
H �W �E, 6
Wa x J M2 >� 0.
p MATERIAL DESCRIPTION
d
2 Z 0 v 0
U) of
F 0
f Sod and Topsoil
w
� 1.0
(SM)Light brown and black silty sand with some gravel and fine organics(medium dense,moist)(Fill)
SM
a 12.5
z
(SM)Light brown silty gravelly sand(medium dense,moist)
a
x
o SM
U
a
z
z 5 _ 5.0
(SM)Light brown silty sand with some gravel(medium dense,moist)
0
SM
z
0
7.0
GB 6 o Qo (GP)Gray sandy gravel with trace silt and thick interbeds of silty sand(medium dense,moist)
0 0
0
Q
En
W o Qo
J
LL O
m Q
o GP a Qo
0
10 oQt)
W
z o Q�
U
H O
Q 11.5
(SP)Gray gravelly sand with trace silt(medium dense,moist)
SIP
N 112.5
No caving observed
oNo groundwater seepage observed
c�
it The depths on the test pit logs are based on an average of measurements across the test pit and should be
considered accurate to 0.5 foot.
LL Bottom of test pit at 12.5 feet.
0
0
0
J
a
x
m
J
W
Z
W
Q
W
O
a
0
0
E3RA,Inc. TEST PIT NUMBER TP-3
PO Box 44840
E3f2& If1C. Tacoma,WA 98448 PAGE 1 1
Telephone: 253-537-9400 Figuree A-4
Fax 253-537-9401
CLIENT Erickson McGovern Architects__ PROJECT NAME _ Main Caw North Mason High School s Improvements
PROJECT NUMBER T13096 _ PROJECT LOCATION _Belfair,Washington
DATE STARTED 9/30/13 COMPLETED 9/30/13 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION ---
NOTES West side of middle school AFTER EXCAVATION ---
W c
a� g LU Cy> v a 0 MATERIAL DESCRIPTION
WWv dD O— vi �J
2z U 0
cal U
F 0
a 2 inches Sod and Topsoil
� -
W (SM)Light brown and black silty gravelly sand with some fine organics(medium dense,moist)(Fill)
SM
1.5
(SM)Light brown silty gravelly sand(medium dense,moist)(Fill)
a SM
U
3.0
(SM)Light brown and gray gravelly sand with some silt and large pockets of sandy silt(loose to medium dense,
= moist)(Fill)
z
0
a
z
z 5
>
0
O
SM
0
U
K
W
M
H
N
J
m 9.0
° (SP)Gray gravelly sand with trace silt(medium dense,moist)
M
10 GB 6
S-1
W
z
U
Q
0
SIP
M
I N
a
H
W
K
U
LL
14.5
0 Slight caving observed from 0 to 7 feet
IL No groundwater seepage observed
IL
= The depths on the test pit logs are based on an average of measurements across the test pit and should be
m considered accurate to 0.5 foot.
Bottom of test pit at 14.5 feet.
W
z
W
c�
0
EL
EL
O
U
E3RA,Inc. TEST PIT NUMBER TP-4
PO Box44840 PAGE 1 OF 1
E3RA, Inc. Tacoma,WA 98448 Figure A-5
Telephone: 253-537-9400
Fax 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Main Campus Improvements
PROJECT NUMBER T13096 PROJECT LOCATION Belfair,Washington
DATE STARTED 9/30/13 COMPLETED 9/30/13 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION ---
NOTES Northwest site AFTER EXCAVATION ---
W c
_ �W _0
wa j o p MATERIAL DESCRIPTION
�Z U U
U
C6 0
a 0.3 4 inches Sod and Topsoil
Cn W SM (SM)Light brown silty gravelly sand(medium dense,moist)
1.0
(GP)Gray sandy gravel with trace silt(medium dense,moist)(Recessional Glacial Outwash)
� o D
a O
U
z O D
� O
N °Qo
2
Z O D
0 O
a
z
Z 5 o D
w GB 6 (3
p S-1 050
� o D
U
z O
Z
O 0 Qo
Y
� o D
L
w
GP OD
U)
w
LL
m O D
O O
0 o Q°
� 10 OD
w
Z o
QU o Q
~ o D
O
o Qo ° o
o D
� O N
030
o O D
W O
LLl
0 Q°
LL O D
0) O
0 15 ° ° 15.0
a No caving observed
= Very slow intermittent groundwater seepage observed below 12 feet
m
The depths on the test pit logs are based on an average of measurements across the test pit and should be
w considered accurate to 0.5 foot.
w Bottom of test pit at 15.0 feet.
LL
0
n
a
0
U
E3RA, Inc. TEST PIT NUMBER TP-5
PO Box 44840 PAGE 1 OF 1
E3RA, InC. Tacoma,WA 98448 Figure A-6
Telephone: 253-537-9400
Fa)c 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Main Campus Improvements
PROJECT NUMBER T13096 PROJECT LOCATION Belfair,Washington
DATE STARTED 9/30/13 COMPLETED 9/30/13 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION ---
NOTES Southwest of planned new high school AFTER EXCAVATION -_
w c
_ w �� C6
a w CO w�U ci a 0 MATERIAL DESCRIPTION
WQ" a j O C6 J
2z U j 9
F 0
- a 0.4 Sod and Topsoil
W (SM)Light brown and black silty sand with some gravel and fine organics(medium dense,moist)(Fill)
F SM
U)
D
12.5
z
(SP-SM)Light brown sand with some gravel and silt(medium dense,moist)
n S P-
z SM
0
U)
4.5
? 5 (SP)Light brown sand with some gravel and trace silt(medium dense,moist)
z
W
(CU7 GB 6
S-1
z
0
Y
SP
w
rn
0
c+>
8 inch thick silt lens at 8 feet
W
J
LL
1 Q
M 9.5
10 °Q (GP)Gray sandy gravel with trace silt(medium dense,moist)
w o D
U Q
Q °Qo
O D
0 0
o Qo
N GP o D
O
O D
W O
D
Q
� o �
LL
o D
0 15 15.0
IL No caving observed
= No groundwater seepage observed;slight mottling near silt lens
m
The depths on the test pit logs are based on an average of measurements across the test pit and should be
W considered accurate to 0.5 foot.
W Bottom of test pit at 15.0 feet.
LL
0
}
0
0
U
E3RA,Inc. TEST PIT NUMBER TP-6
PO Box 44840 PAGE 1 OF 1
E3R& Inc. Tacoma,WA 98448 Figure A-7
Telephone: 253-537-9400
Fax 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Main Campus Improvements
PROJECT NUMBER T13096 PROJECT LOCATION Belfair,Washington _
DATE STARTED 9/30/13 COMPLETED 9/30/13 GROUND ELEVATION _ TEST PIT SIZE
EXCAVATION CONTRACTOR GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION _---_
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION
NOTES West side planned new school AFTER EXCAVATION ---
I W
a-
m: w (6 v
wJ p MATERIAL DESCRIPTION
o a
2 z c�
F 0
a [5.0
Sod and Topsoil
w (SM)Brown and black silty sand(medium dense,moist)(Fill)
SM
D (SM)Dark brown silty gravelly sand with copious fine organics(loose to medium dense,moist)(Fill)
Q-
azSM
0
z
5
w (SP)Gray gravelly sand with trace silt(medium dense,moist)
0 SP
U 6.0
z No caving observed
N No groundwater seepage observed
Y
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
accurate to 0.5 foot.
Bottom of test pit at 6.0 feet.
W
w
J
LL
m
fh
O
W
Z
U
a
F
m
0
0
N
0
H
U
111
0
0
LL
N
J
a
x
m
J
W
W
Z
W
U'
LL
0
0.
0
E3RA,Inc. TEST PIT NUMBER TP-7
PO Box 44840 PAGE 1 OF 1
E3R& If1C. Tacoma,WA 98448 Figure A-8
Telephone: 253-537-9400
_ Fax 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME _North Mason High School Main Campus Improvements
PROJECT NUMBER T13096 PROJECT LOCATION _Belfair,Washington_
DATE STARTED 9/30/13 COMPLETED 9/30/13 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR _ GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION ---
NOTES North part septic alignment AFTER EXCAVATION ---
W
�
_ W vi U
2
a-� CO �? a p MATERIAL DESCRIPTION
W d2i In �J
Z zi
(�
~ 0
a —1 0Sod and Topsoil
0 ,
W
1.0
M (SM)Light brown silty sand with some gravel(medium dense,moist)
V
a SM
UU
z 3.0
(SP-SM)Gray gravelly sand with some silt(medium dense,moist)
x
o SP-
a SM
z
z 5 5.0
w (ML)Gray and mottled gravelly sandy silt(stiff to hard,moist)
0
0
ML
z
0
cYi 7.0
W No caving observed
0
Moderate to rapid groundwater seepage observed from 5 to 6 feet
N The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
Uj
accurate to 0.5 foot.
LL Bottom of test pit at 7.0 feet.
m
0
0
3
W
z
U
Q
F-
0
_o
co
N
O
H
W
K
D
LL
O
J
a
x
m
J
W
Z
W
0
LL
0
1
a
O
0
E3RA, Inc. TEST PIT NUMBER TP-8
PO Box 44840
E3R& Inc. Tacoma,WA 98448 PAGE 1 1
Telephone: 253-537-9400 Figuree A-9
Fax 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Main Camps Improvements
PROJECT NUMBER T13096 PROJECT LOCATION Belfair,W shington
DATE STARTED 9/30/-13 COMPLETED 9/30/13 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION -
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION ---
NOTES South part septic alignment _ AFTER EXCAVATION ---
W
= aW U
d W CO a U
W _g (6 O MATERIAL DESCRIPTION
0 0
z (�
F 0
a 2 inches Sod and Topsoil
GP (GP)Light brown sandy gravel with trace silt(medium dense,moist)
o D
m O
1.5
j (SP)Gray and lightly mottled sand with trace silt and gravel(medium dense,moist)
a
a
z SP
a
x
0 4.0
z (ML)Gray and mottled gravelly sandy silt(stiff to hard,moist to wet)
z
z 5
Uj
0
c�
zi ML
0
Y
U
K
w
m
rn
0
8.0
wNo caving observed
No groundwater seepage observed
w
m
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
accurate to 0.5 foot.
Bottom of test pit at 8.0 feet.
W
w
z
U
Q
N
0
o_
a
N
O
W
LL
co
O
J
a
x
m
J
Q
W
W
Z
W
U'
0
a
O
U
E3RA,Inc. TEST PIT NUMBER TP-9
s PO Box 44840 PAGE 1 OF 1
E R& If1C. Tacoma,WA 98448
Telephone: 253-537-9400 Figure A-10
Fax: 253-537-9401
CLIENT _Erickson McGovern Architects_ . _ PROJECT NAME North Mason High School Main Campus Improvements
PROJECT NUMBER T13096 _ PROJECT LOCATION _Belfair,Washington
DATE STARTED 9/30/13 COMPLETED 9/30/13 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION ---
NOTES Southeast of planned bldg near tennis courts AFTER EXCAVATION ---
w c
w
_ �m Q .0 (j _
a w w cU o-O MATERIAL DESCRIPTION
'o- � IJ
a Q Z W = 0
F 0
a 0.4 Forest Duff
Uj SP- (SP-SM)Light brown gravelly sand with some silt(medium dense,moist)
SM
1.5 _
DIJ
° (GP)Gray sandy gravel with trace silt(medium dense,moist)(Recessional Glacial Outwash)
0 Q(L
a o D
U O
z o Q
o
U) o D
z O
3°
� o D
z O
Z 5 °�o
w GB 6
0 S-1 O D
U
0 o D
0 O
U �o
W °
� o D
M O 1 foot thick interbed of gravelly sand at 7.5 feet
GP
W
O D
LL O
m
10
w
0 O D
U O
F
o D
o O
N
O D
O
C�o
� o D
O
14.5
0 No caving observed
0
a No groundwater seepage observed
r
mThe depths on the test pit logs are based on an average of measurements across the test pit and should be
considered accurate to 0.5 foot.
I Bottom of test pit at 14.5 feet.
z
w
0
LL
0
0
0
U
E3RA,Inc. TEST PIT NUMBER TP-10
s PO Box 44840 PAGE 1 OF 1
E R& Inc. Tacoma,WA 98448
Telephone: 253-537-9400 Figure A-11
Fax 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Main Campus Improvements
PROJECT NUMBER T13096 __ PROJECT LOCATION Belfair,Washinqton
DATE STARTED 9/30/13 COMPLETED 9/30/13 GROUND ELEVATION TEST PR SIZE
EXCAVATION CONTRACTOR GROUND WATER LEVELS:
EXCAVATION METHOD AT TIME OF EXCAVATION ---
LOGGED BY FER CHECKED BY JEB AT END OF EXCAVATION ---
NOTES Planned storm water pond,south site AFTER EXCAVATION ---
W c
a —
}W
w w j W 0 �O MATERIAL DESCRIPTION
a�
a QZ Ovzi
0
a 0.3 4 inches Sod
F (SM)Brown and black silty sand with copious fine organics(loose,moist)(Topsoil/sandy fill mix)(Fill)
m
SM
z
a
x
z
0
U)
a
14.5
z 5 (SP)Gray sand with trace silt(loose to medium dense,damp)
w GB 6
0 S-1
SP
0
UU 7.0 _
w (SM)Gray and mottled silty gravelly sand(dense,damp)(Glacial Till)
M
GB
S-2 6 SM
LL
co
M
O
10 1 1 1 1 110.0
W No caving observed
No groundwater seepage observed
a
The depths on the test pit logs are based on an average of measurements across the test pit and should be
o considered accurate to 0.5 foot.
Bottom of test pit at 10.0 feet.
N
N
O
H
W
C7
LL
N
J
a
x
m
J
LU
W
W
W
LL
0
a
U
U
E3RA,Inc. BORING NUMBER TH-1
PO Box 44840
E3RA, -Inc. Tacoma,WA 98448 PAGE 1 1
Telephone: 253-537-9400 Figure Al2
Fax 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME _North Mason High School Main Campus Improvements
PROJECT NUMBER T13096 _ PROJECT LOCATION Belfair,Washington
DATE STARTED 10/1/13 COMPLETED 10/1/13 GROUND ELEVATION HOLE SIZE
DRILLING CONTRACTOR GROUND WATER LEVELS:
DRILLING METHOD AT TIME OF DRILLING ---
LOGGED BY FER CHECKED BY JEB AT END OF DRILLING ---
NOTES North of north goal post,new school footprint AFTER DRILLING ---
W
a Wm U [L0
W g 6 MATERIAL DESCRIPTION
0 0_�
2z
a <
� V)
F 0
a — 8 inches Sod and Topsoil
0.7
W
(SM)Brown silty gravelly sand(medium dense,moist)(Fill)
0
M SM
i=
12.0
a (SP-SM)Brown gravelly sand with some silt(medium dense,moist)
z SP-
SM
i 13-5
o (SP)Gray gravelly sand with trace silt(medium dense,moist)(Recessional Glacial Outwash)
U) SP
a
4.5
Z No caving observed
W No groundwater seepage observed
W
0 The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
accurate to 0.5 foot.
o Bottom of borehole at 4.5 feet.
N
Y
U
K
W
D
m
O
M
H
V)
W
J
LL
m
0
7
M
O
N
W
Z
U
a
H
0
_o
M
N
N
O
W
W
D
LL
J
a
x
m
J
W
W
Z
W
(7 LL
0
}
a
0
0
E3RA,Inc. BORING NUMBER TH-2
PO Box 44840
PAGE 1 OF 1
E3 Inc. Tacoma,WA 98448
Telephone: 253-537-9400 Figure A-13
Fax 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME _North Mason High School Main Campus—Improvements _
PROJECT NUMBER T13096 — PROJECT LOCATION Belfair,Washington__
DATE STARTED 10/1/13 COMPLETED 10/1/13 GROUND ELEVATION HOLE SIZE
DRILLING CONTRACTOR GROUND WATER LEVELS:
DRILLING METHOD AT TIME OF DRILLING ---
LOGGED BY FER CHECKED BY JEB AT END OF DRILLING ---
NOTES South of south goal post,new school footprint AFTER DRILLING ---
W
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r W m 0 0-t7
W -j g U) Q O MATERIAL DESCRIPTION
p �Z
a Q
0
aw
SM 1 inch of Sod
W —-\ (S11 )Gray sand with some silt(medium dense,moist)(Fill)
01
(SM)Brown silty gravelly sand with copious fine organics(medium dense,moist)(Fill)
M
H
SM
D
Grades to loose
0
a 3.0
(SP)Light brown gravelly sand with some silt(medium dense,moist)(Recessional Glacial Outwash)
x
0
a
z SID
z 5
cr
W
0
6.0
z No caving observed
° No groundwater seepage observed
U
W The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
accurate to 0.5 foot.
Bottom of borehole at 6.0 feet.
U)
W
J
LL
m
fh
O
W
W
Z
U
Q
F-
n
0
_o
c'
N
N
O
F
W
x
D
C7
LL
N
C7
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J
a
x
m
J
Uj
W
Z
W
U
0
O
y
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U
APPENDIX B
LABORATORY TESTING RESULTS
Particle Size Analysis Summary Data
Job Name: North Mason School District
Job Number. T13096
Tested By: ZL
Date: 10/2/13
Boring#: TP-1
Sample#: 1
Depth: 5.5'
Moisture Content(%) 4.70/6
Percent Percent By
Sieve Size Passing (%) Size Fraction g
Weiht
3.0 in. (75.0) 100.0 Coarse Gravel 16.2
1.5 in. (37.5) 100.0 Fine Gravel 28.1
3/4 in. (19.0) 83.8
3/8 in. 9.5-mm) 66.2 Coarse Sand 6.8
No. 4 (4.75-mm) 55.7 Medium Sand 11.1
No. 10 (2.00-mm) 48.9 Fine Sand 35.6
No. 20 (.850-mm) 44.3
No.40(.425-mm) 37.7 Fines 2.1
No.60 (250-mm) 20.7 Total 100.0
No. 100(150-mm) 7.3
No. 200 (075-mm) 2.1
ILL
PI
D10 0.17
D30 0.33
D60 6.31
Cc 0.11
Cu 37.96
ASTM Classification
Group Name Brown poorly graded sand with gravel
Symbol (SP)(med. dense, moistE3RA )
Figure
Soil Classification Data Sheet
Sample Distribution
U.S. Standard Sieve Sizes
--�
3" 1.5" 3l4" aie" n 10 20 40 BO 100 200 -Sample Distribution
100 I I I I I
90
80
70
an
.y
60
N
a
50
w
c
d
m
40
a
30
20
10
0
1000 100 10 1 0.1 0.01 0.001
Particle Size (mm)
Sample Distribution Job Name: North Mason School District Sample#: 1
Job Number: T13096 Date: 10/2/13
E3RAFigure: Tested By: ZL Depth: 5.5'
Exploration #: TP-1
Particle Size Analysis Summary Data
Job Name: North Mason School District
Job Number: T13096
Tested By: ZL
Date: 10/2/13
Boring#: TP-4
Sample#: 1
Depth: 5.5'
Moisture Content 4.4%
Percent Percent By
Sieve Size Passing (%) Size Fraction Weight
3.0 in_ (75.0) 100.0 Coarse Gravel 15.7
1.5 in. (37.5) 100.0 Fine Gravel 46.7
3/4 in. (19.0) 84.3
3/8 in. (9.5-mm) 56.0 Coarse Sand 12.5
No.4 (4.75-mm) 37.6 Medium Sand 13.4
No. 10(2.00-mm) 25.1 Fine Sand 10.7
No. 20(.850-mm) 17.7
No. 40 (.425-mm) 11.7 Fines 1.0
No.60(.250-mm) 5.5 1Total 1 100.0
No. 100(150-mm) 1.9
No. 200 (.075-mm) 1.0
ILL
PI
D10 0.37
D30 2.81
D60 10.47
Cc 2.05
Cu 28.51
ASTM Classification
Group Name Brown well-graded gravel with sand
Symbol (GW)(coed, dense, moist)
E3RA Figure
Soil Classification Data Sheet
Sample Distribution
U.S. Standard Sieve Sizes
3" 1.5" 314 ale" 4 10 20 40 80 100 200 --*—Sample Distribution
100 I
90
80
70
CM
60
iv
a 50
c
as
m
40
a
30
20
10 TT
0
-L- H I I I I
1000 100 10 1 0.1 0.01 0.001
Particle Size (mm)
Sample Distribution Job Name: North Mason School District Sample#: 1
Job Number: T13096 Date: 10/2/13
E3RAF!gure: Tested By: ZL Depth: 5.5'
Exploration#: TP-4
Particle Size Analysis Summary Data
Job Name: North Mason School District
Job Number: T13096
Tested By: ZL
Date: 10/2/13
Boring#: TP-5
Sample* 1
Depth: 5.5'
Moisture Content(%) 61%
Percent Percent By
Sieve Size Passing (%) Size Fraction Weight
3.0 in. (75.0) 100.0 Coarse Gravel
1.5 in. (37.5) 100.0 Fine Gravel 6.9
314 in. (19.0) 100.0
3/8 in. (9.5-mm) 97.1 Coarse Sand 4.8
No. 4 (4.75-mm) 93.1 Medium Sand 16.3
No. 10 (2.00-mm) 88.4 Fine Sand 68.0
No. 20 (.850-mm) 84.0
No. 40(.425-mm) 72.1 Fines 4.0
No. 60 (.250-mm) 43.1 Total 100.0
No. 100(.150-mm) 15.8
No. 200 (.075-mm) 4.0
ILL
PI
D10 0.11
D30 0.20
D60 0.34
Cc 1.05
Cu 3.19
ASTM Classification
I
Group Name Brown poorly graded sand =.
Symbol (SP)(med. dense, moist)
1
E3RA
Figure
Soil Classification Data Sheet
Sample Distribution
U.S. Standard Sieve Sizes
—�—3" 1.5" 314" 3I8" 4 �0 20 40 60 100 200 Sample Distribution
100 I
90
80
70
60
,N
N
a 50
c
m
d
40
a
30
20
10
0
1000 100 10 1 0.1 0.01 0.001
Particle Size (mm)
Sample Distribution Job Name: North Mason School District Sample#: 1
Job Number: T13096 Date: 10/2/13
E3RAFigure: Tested By: ZL Depth: 5.5'
Exploration #: TP-5
Particle Size Analysis Summary Data
Job Name: North Mason School District
Job Number_ T13096
Tested By: ZL
Date: 10/2/13
Boring#: TP-9
Sample#: 1
Depth: 5.5'
Moisture Content(%) 6.1%
Sieve Size Percent Size Fraction Percent By
Passing(%) Weight
3.0 in. (75.0) 100.0 Coarse Gravel 4.4
1.5 in. (37.5) 100.0 Fine Gravel 31.9
3/4 in. (19.0) 95.6
3/8 in. (9.5-mm) 801 Coarse Sand 21.6
No. 4 (4.75-mm) 63.7 Medium Sand 35.3
No. 10(2.00-mm) 42.1 Fine Sand 4.9
No. 20(.850-mm) 18.4
No.40(425-mm) 6.8 Fines 1.9
No. 60(.250-mm) 3.0 ITotal 100.0
No. 100(.150-mm) 2.1
No.200 (.075-mm) 1.9
ILL
PI
D10 0.52
D30 1.29
D60 4.10
Cc C.79
Cu 7.96
AsTM Qassificabon
i
Group Name Brown poorly graded sand with gravel
Symbol (SP)(med. dense, moist)
Figure
E3RA Soil Classification Data Sheet
Sample Distribution
U.S. Standard Sieve Sizes
--�3" 1.5" 3/4' 318" 4 10 20 40 80 100 200 Sample Distribution
100
90
80
70
.N
60
N
l0
a 50
c
m
40
m
a
30
20
10
0
1000 100 10 1 0.1 0.01 0.001
Particle Size (mm)
Sample Distribution Job Name: North Mason School District Sample#: 1
Job Number: T13096 Date: 10/2/13
E3RAFigure: Tested By: ZL Depth: 5.5'
Exploration#: TP-9
Particle Size Analysis Summary Data
Job Name: North Mason School District
Job Number: T13096
Tested By: ZL
Date: 1012/13
Boring#: TP-10
Sample#: 2
Depth: 8'
Moisture Content(%) 1 8.5%
Sieve Size Percent Size Fraction Percent By
Passing(%) Weight
3.0 in. (75.0) 100.0 Coarse Gravel 25.3
1.5 in. (37.5) 87.3 Fine Gravel 17.8
3/4 in. (19.0) 74.7
3/8 in. (9.5-mm) 68.3 Coarse Sand 6.4
No. 4 (4.75-mm) 56.9 Medium Sand 10.6
No. 10(2.00-mm) 50.5 Fine Sand 24.5
No. 20(.850-mm) 45.2
No. 40(.425-mm) 39.9 Fines 15.4
No. 60(250-mm) 32.8 Total 100.0
No. 100(150-mm) 24.7
No. 200(075-mm) 15.4
ILL
PI
D10
D30 0.21
D60 5.74
Cc
cu
ASTM Classification
Group Name Brown silty gravel with sand
Symbol (GM)(med. dense, N/A)
Figure
E3RA Soil Classification Data Sheet
Sample Distribution
U.S. Standard Sieve Sizes
3" 1.5" 3/4" 3/8" 4 10 20 40 60 100 200 —6 Sample Distribution
100 I
90
80
70
CM
.y
60
�v
a 50
c
a�
40
m —
a
30
20
10
0
1000 100 10 1 0.1 0.01 0.001
Particle Size (mm)
Sample Distribution Job Name: North Mason School District Sample#: 2
Job Number: T13096 Date: 10/2/13
E3RAFigure: Tested By: ZL Depth: 8'
Exploration #: TP-10