HomeMy WebLinkAboutSWP272285(2) •
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• GEOTECHNICAL REPORT
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• Farwest Steel
SW 34th Street
• Renton, Washington
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• Project No. T-3064
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4 Terra Associates Inc.
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y Farwest Steel Corporation
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101111
Eugene, Oregon
• CITY vF HENTON�
RECEIVED Y
Februar 1 , 1996
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MAY 0 S 1996
BUILDING DIVISIO �Z
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TES, Inc.TERRA ASSOCIA
«' -a Consultants in Geotechnical Engineering, Geology
i� and
Environmental Earth Sciences
February 1, 1996
Project No. T-3064
Mr. Dave Forester
• Farwest Steel Corporation
P.O. Box 889
• Eugene, Oregon 97440
Subject: Geotechnical Report
Farwest Steel
SW 34th Street
• Renton,Washington
Dear Mr. Forester:
As requested, we have conducted a geotechnical engineering study for the subject project. The attached
report presents our findings and recommendations for the geotechnical aspects of project design and
construction.
In general,the site is underlain by five to six feet of dense granular fill over several feet of organic silt or
peat. The organic silt and peat are underlain by medium dense to dense alluvial sands. A six to seven
foot thick layer of very soft silty clay is present at a depth of about 32 feet below existing site grades.
Medium dense silty sand underlies the very soft silty clay.
To reduce post-construction settlements to tolerable levels, we recommend that the building area be pre-
loaded with a surcharge fill. Following successful completion of the surcharge program, the proposed
steel fabrication facility may be constructed using conventional spread footings placed on the new
structural fill pad. The intolerance of the rail cranes to foundation settlement requires using a pile
foundation. The piles must extend through the very soft silty clay found at a depth of 32 feet in order to
minimize the potential impact to them from differential settlement across the site as a result of long-term
compression of the silty clay.
12525 Willows Road, Suite 101, Kirkland, Washington 98034 • Phone (206) 821-7777
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Mr. Dave Forester
• February 1, 1996
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• We appreciate the opportunity to be of service during the initial design phase of this project and look
forward to working with you during the design and construction phases. We trust the information
• presented in this report is sufficient for your current needs. If you have any questions or need additional
• information, please call.
• Sincerely yours,
• TER S INC.
1« �,OV cp v�Qs �
• Kev if Robe
Proj4ct 1,ngin i•'
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U -\o Vh 02-/ - 96,
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Theodore J¢ 'e er, P.E.
• P� s1` i 97�`�
• KPR/TJS:Ih
cc: Mr. Bart Treece, Horton Dennis and Associates, Inc.
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Project No. T-3064
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TABLE OF CONTENTS
Page
1.0 Project Description 1
2.0 Scope of Work 1
3.0 Site Conditions 2
3.1 Surface 2
. 3.2 Soils 2
3.3 Groundwater 3
• 3.4 Seismic Hazards 3
4.0 Discussion and Recommendations 3
4.1 General 3
4.2 Site Preparation and Grading 4
4.3 Surcharge and Settlements 5
4A Spread Footing Foundations 7
4.5 Rail Crane Foundation- Steel H-Piles 7
4.6 Rail Crane Foundation-Augercast Piling 8
4.7 Slab-on-grade Floors 8
4.8 Excavations 9
4.9 Utilities 9
4.10 Lateral Earth Pressures 9
4.11 Drainage 10
4.12 Pavements 10
5.0 Additional Services 11
6.0 Limitations 11
• Fi ures
Vicinity Map Figure 1
• Exploration Location Plan Figure 2
Typical Settlement Marker Detail Figure 3
• Reinforced Soil Wall Section Figure 4
Appendix
Field Exploration and Laboratory Testing Appendix A
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Geotechnical Report
• Farwest Steel
SW 34th Street
Renton, Washington
1.0 PROJECT DESCRIPTION
The project will consist of constructing a new steel fabrication plant in Renton,Washington. The location of the
project site is shown on the Vicinity Map, Figure 1. A conceptual site plan dated November 15, 1995, shows
the location of the 96,000 square foot steel fabrication building and an attached 4,000 square foot office space.
Finished floor grades are expected to be seven to eight feet above existing site grades. Access to the building
will be from the south from an easement connecting to Lind Avenue. Traffic loading is expected to be heavy
along the easement and in parking areas at the perimeter of the structure.
• The steel fabrication facility will consist of steel-frame construction with dock-high floors. We understand that
the lower portion of the perimeter walls may be constructed using pre-cast concrete tilt-up wall panels, with the
® upper portion finished with a metal skin exterior. Floor loadings are expected to be relatively high, possibly 800
to 1,000 pounds per square foot (pso. We understand you wish to support the building using a spread footing
foundation. Overhead rail cranes will also be used in the facility for interior transport of materials and products.
We understand the cranes have a low tolerance for differential settlement.
lei The recommendations in the following sections of this report are based on our understanding of the project's
• design features. We should review final design drawings and specifications to verify that our recommendations
have been properly interpreted and incorporated into project design.
2.0 SCOPE OF WORK
On January 9 through 11, 1996, we drilled six test borings at the site to depths ranging between 9 and 59 feet
below existing site grades. Using the information obtained from the subsurface exploration, we performed
analyses to develop geotechnical recommendations for project design and construction. Specifically, this report
addresses the following:
• Soil and groundwater conditions
• Site preparation and grading
• Foundation alternatives
• Surcharge and settlements
• Lateral earth pressures
• Slab-on-grade floors
• Utilities
• Pavements
• Drainage requirements
• February 1, 1996
Project No. T-3064
3.0 SITE CONDITIONS
• 3.1 Surface
• The subject site is located on SW 34th Street between Lind Avenue and the East Valley Highway in Renton,
Washington. This location is shown on Figure 1. The site is bounded to the south and north by a HomeBase
store and SW 34th Street, respectively. Open, undeveloped parcels bound the site on the east and west.
The site and vicinity are flat. We noted a large pile of fill and debris near the northwestern corner of the site.
An absence of vegetation indicated that relatively recent grading was completed over the central and western
portions of the site. The southwestern and eastern portions of the site contained areas of standing water and
were vegetated with sparse grasses. The proposed access easement area in the vicinity of Boring B-2 was flat
and contained very sparse grasses and some standing water.
S Two existing railroad spur tracks enter the property from the north and curve westward v6thin the property to
join a railroad line extending west across Lind Avenue. The tracks were raised slightly above surrounding
grades. Shallow ditches filled with standing water were observed adjacent to each of the spur lines. No other
obvious signs of surface water drainage were observed at the site.
3.2 Soils
The soil conditions at the site generally consist of silty sand and sand with gravel fill overlying a variably thick
layer of compressible peat or organic clayey silt. The compressible soils were underlain by generally competent
sand deposits. The sand was found overlying loose to medium dense silty sand, with a layer of very soft silty
• clay present at the northern portion of the site at a depth of about 32 feet.
• All of our borings showed fill soil comprised of gravelly to silty sand to depths ranging from four to seven feet.
This material was generally dense but became loose near the contact with the underlying native clayey silt and
peat. The compressible native soil under the fill consisted mostly of gray to brown-gray, soft to stiff organic
• silt, and silty clay occurring to depths of eight to nine feet. As shown by Boring B-1, dark brown soft to
medium stiff peat underlies the fill to a depth of about 12 feet at the southern portion of the site.
We observed black medium dense to very dense sand underlying the compressible strata. At Borings 13-1 and B-
6, we found dark gray silty sand with shells that was loose to medium dense at a depth of about 36 feet. Boring
B-5 also showed gray very soft silty clay with shells overlying the gray silty sand between depths of about 30
and 37 feet. All borings were terminated within the black medium dense to very dense sand or gray medium
dense silty sand with shells. Figures A-2 through A-7 in Appendix A present more detailed descriptions of the
subsurface conditions encountered in the test borings. The approximate test boring locations are shown on
Figure 2.
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Page No. 2
• February 1, 1996
Project No. T-3064
The Geologic Map of the Renton Quadrangle, King County, Washington by D.R. Mullineaux (1965) shows
that the soils are mapped as peat (Qlp). The peat encountered in Boring B-1 correlates with the published
description. However, the native organic silt and clay underlying the fill at the site correlates better with the
description of the nearby mapped alluvium(Qaw).
_ 3.3 Groundwater
j We encountered groundwater in all of the test borings at depths ranging from ground surface to seven feet.
Some of the groundwater encountered near the ground surface appeared to consist of a perched zone of
infiltration from recent heavy rains. In general,the groundwater table was found at depths ranging between four
and seven feet.
Due to its flat nature, groundwater depths are not expected to vary significantly over the site. However, we
expect some seasonal fluctuations in the position of the groundwater table.
• 3.4 Seismic Hazards
The Puget Sound area falls within Seismic Zone 3 as classified by the Uniform Building Code (UBC). Based on
the soil conditions encountered and the local geology, Table 16-J of the 1994 UBC indicates a site coefficient of
1.5 should be used in design of the structure.
We reviewed the results of our field and laboratory testing in order to assess the potential for liquefaction of the
site's soils during an earthquake. Liquefaction is a phenomenon where there is a reduction or complete loss of
soil strength due to an increase in pore water pressure induced by vibrations from a seismic event. Based on the
information obtained and considering the additional confining stresses from the building and fill weight, it is our
• opinion that the risk of liquefaction-related impacts to the structure are minimal.
• 4.0 DISCUSSION AND RECOMMENDATIONS
4.1 General
x Based on our study, in our opinion, there are no geotechnical constraints that would preclude construction of the
proposed steel fabrication facility. For building loads, the primary geotechnical concern for construction at this
site is the three to five foot thick layer of organic silt and peat at depths of 6 to 12 feet below existing grades.
With these conditions, a surcharge program will need to be completed in order to support the facility using
standard spread footing construction. The purpose of the surcharge is to consolidate the compressible soil
layers to limit post-construction settlements to an amount that the structure can tolerate.
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Page No: 3
• February 1, 1996
- Project No. T-3064
The overhead rail crane's intolerance of settlement imposes additional geotechnical constraints on the design and
placement of its foundation. Though competent sands underlie the organic clayey silt and peat at the site, these
sands are underlain by a seven-foot thick layer of very soft silty clay at a depth of 30 feet. Our analysis
indicates that the site will experience long-term total and differential settlement as this layer consolidates under
the building and fill pad loads. While these long-term settlements may be tolerated by the building, we expect
their magnitude to exceed what could be tolerated by the crane. It will therefore be necessary to transfer the
crane's loads through the competent sands and underlying very soft silt to the medium dense to dense sand and
silty sand.
The following sections provide detailed recommendations regarding the above issues and other geotechnical
design considerations. These recommendations should be incorporated into the final design drawings and
construction specifications.
it 4.2 Site Preparation and Grading
-Y Following clearing, the fill surface should be proofrolled with heavy construction equipment prior to placement
of additional fill. Soft, }Melding areas should be overexcavated to firm bearing soil and replaced with structural
fill. Where excavations to achieve firm conditions are excessive, the use of a geotextile fabric such as Mirafi
500X in conjunction with limited overexcavation and replacement with a structural fill can be considered.
Typically, 18 inches of clean granular structural fill over the fabric will achieve a stable subgrade.
Our laboratory results show that the existing fill was above its optimum moisture content at the time of our
investigation. Some of the fill soils encountered at the site contain up to 14 percent by weight of fines and will
be difficult to compact if the moisture conditions cannot be carefully controlled. Extreme care should be taken
to ensure that exposed surfaces of the on-site fill do not become disturbed due to weather and construction
• traffic. Moreover, the ability to use these soils as structural fill will depend on their moisture content and the
prevailing weather conditions at the time of construction. It will be difficult to achieve proper compaction of
these soils when their moisture content is above optimum. When the moisture is excessive, the soil can be dried
• by aeration to a moisture content which will allow for proper compaction.
We recommend that the structural fill required to achieve site grades consist of inorganic granular soil meeting
the following grading requirements:
Maximum Aggregate Size 6 inches
• Minimum Retained on the No. 4 Sieve 25 percent
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Maximum Passing the No. 200 Sieve 25 percent
• (Based on the Minus 3/4-inch Fraction) (see following narrative)
If fill placement takes place during wet weather, or if the moisture conditions of the fill material cannot be
controlled, consideration should be given to importing fill soil that conforms with the above gradation, but with
the maximum passing the No. 200 sieve reduced to five percent.
Page No.4
February 1, 1996
Project No. T-3064
Structural fill materials should be placed in uniform loose layers not exceeding 12 inches and compacted to a
minimum of 95 percent of the soil's maximum density, as determined by ASTM Test Designation D-698
(Standard Proctor). The moisture content of the soil at the time of compaction should be within about two
i percent of its optimum, as determined by this same ASTM method.
Prior to placing foundations and floor slabs, we recommend probing or proofrolling the structural fill surfaces to
determine if any isolated soft and yielding areas are present. As discussed above, soft or yielding areas should
be overexcavated and filled to grade with structural fill or crushed rock. It may be necessary to protect
foundation and slab areas with lean mix or a layer of crushed rock to guard against soil degradation.
Construction traffic must not be allowed on subgrades that have been prepared just prior to foundation or slab
placement. A representative of Terra Associates, Inc. should observe all proofrollmg operations. We also
• recommend field evaluations at the time of construction to verify stable subgrades.
4.3 Surcharge and Settlements
As discussed, for spread footing foundation support and slab-on-grade construction, we recommend placing a
surcharge fill over the building area. The surcharge program is necessary to limit building settlements to what
may be considered tolerable levels. Our surcharge and settlement analysis is based on an assumed existing
ground surface elevation of 12 feet. In addition, our analysis is based on a finished floor (top-of-slab) elevation
of about 20 feet, and the anticipated floor loads discussed above. We should review the final foundation and
grading plans in order to better assess expected settlements.
Primary Consolidation
The site grades should be raised using structural fill as outlined in the Site Preparation and Grading section.
Once grade is achieved, an additional eight feet of fill should be placed as a surcharge. This surcharge fill does
not need to meet any special requirements other than having a minimum in-place unit weight of 125 pounds per
cubic foot (pcf). However, it may be advisable to use a good quality fill which could be used to raise grades in
other portions of the site, such as parking and driveway areas, if necessary.
• We do not believe it to be necessary to place a surcharge of fill within the parking and access easement areas if
grades at these areas are raised to elevations comparable to the building area. In any case, the structural fill pad
in the pavement areas should be placed concurrently with the structural fill in the building areas to allow enough
time for consolidation of the compressible layers and reduction of potential settlements.
The estimated total primary settlements under the recommended surcharge range from 12 to 18 inches across the
building area. These settlements are expected to occur 12 to 16 weeks following full application of the
• surcharge loading. The actual period for completion and magnitude of the primary settlements will be governed
by variations in subsurface conditions at the site.
Page No. 5
February 1, 1996
Project No. T-3064
The rate of consolidation can be accelerated by installing sand or wick drains at regularly spaced intervals
• throughout the pre-load fill pad. Alternatively, an additional thickness of fill surcharge will accelerate the rate
of primary settlement. The sand drains should penetrate a minimum of five feet into the gray-black fine sand
underlying the organic silt or peat layers. With the pre-load pad in place, we estimate the sand drains will be 30
• to 35 feet long. Proprietary wick drains may be used in lieu of sand drains. We can provide specific
recommendations for either option if acceleration of the surcharge settlement period is desired.
To verify the amount of settlement and the rate of movement, the surcharge program should be monitored by
installing settlement markers. A typical settlement marker installation is shown on Figure 3. The settlement
• markers should be installed on the existing grade prior to placing any building or surcharge fills. Once installed,
elevations of both the fill height and marker should be recorded daily by a registered land surveyor until the full
height of the surcharge is in place. Once fully surcharged, readings should continue weekly until the anticipated
settlements have occurred.
It is critical that the grading contractor recognize the importance of the settlement marker installations. All
efforts must be made to protect the markers from damage during fill placement. It is difficult, if not impossible,
" to evaluate the progress of the surcharge program if the markers are damaged or destroyed by construction
• equipment. As a result, it may be necessary to install new markers and to extend the surcharging time to ensure
that settlements have ceased and building construction can begin.
We recommend that the surcharge pad extend a minimum of five feet beyond the building perimeter and then
slope down at an inclination of 1:1 (Horizontal:Vertical). The conceptual site plan shows the northern building
perimeter may be 20 feet from SW 34th Street. This would place the toe of the 15-foot high fill pad at the edge
• of the roadway. Where sufficient area is not available to slope the surcharge and to reduce impact of
_ settlements due to surcharge on the existing roadways, the surcharge may be supported at a near vertical
inclination(minimum 1:12)using reinforced soil wall. Figure 4 shows a typical reinforced soil wall section.
Post-construction Settlements
Primary consolidation of compressible soils at the site will be achieved upon completion of the surcharge (pre-
load) program. Secondary consolidation will continue at the site throughout the life of the structure.
During secondary consolidation, you should expect a maximum post-construction total settlement of 1.5 inches,
and differential settlement of 3/4 inch. These values represent expected settlements over a 50 year period. We
anticipate that most of these settlements will occur within five to ten years after completion of the structure.
Impact of Surcharge on Adjacent Roadway and Utilities
Depending on its location, the proximity of the surcharge fill pad to SW 34th Street and the railroad spurs may
result in settlement of these structures due to soil beneath them being influenced by the preload fill pad. We
recommend placing monitoring points on the roadway curbs and pavement to record possible movements during
surcharge. A similar monitoring program should be implemented for the railroad spurs if they cannot tolerate
possible settlement from the pre-load.
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Page No. 6
• February 1, 1996
Project No. T-3064
Sufficient monitoring points should be established since some of these points will likely be disturbed by traffic.
In addition, we suggest making a photographic survey of the pavement before placing the surcharge to identify
development of new cracks during and after the area is surcharged.
• We understand a fiber optic telephone transmission cable is located within a utility easement adjacent to SW
34th Street. This utility line as well as other utilities within the easement may experience vertical and/or lateral
movement as a result of the stress changes in the soil associated with the placement of a pre-load fill pad.
Utility organizations should be prepared to relocate utilities as required prior to construction of the pre-load.
• 4.4 Spread Footiniz Foundations
Following the successful completion of the surcharge program, if the above estimated settlements are considered
tolerable, the building may be supported on conventional spread foundations bearing on a minimum of two feet
of structural fill. Existing competent fills may be included in determining the depth of the structural fill.
Perimeter foundations exposed to the weather should be at a minimum depth of 1.5 feet below final exterior
grades.
We recommend designing foundations for a net allowable bearing capacity of 3,000 psf. For short-term loads
such as wind and seismic, a 1/3 increase in this allowable capacity can be used. With the anticipated loads and
bearing stresses,the estimated total settlements are as discussed in the Secondary Settlements section.
For designing foundations to resist lateral loads, a base friction coefficient of 0.4 can be used. Passive earth
pressures acting on the side of the footing and buried portion of the foundation stem wall can also be considered.
We recommend calculating this lateral resistance using an equivalent fluid weight of 350 pcf. We recommend
not including the upper 12 inches of soil in this computation because they can be affected by weather or
disturbed by future grading activity. This value assumes the foundation will be constructed neat against
competent fill soil or backfilled with structural fill as described in the Site Preparation and Grading section. The
recommended lateral resistance value includes a safety factor of 1.5.
4.5 Rail Crane Foundation - Steel H-Piles
We understand you are considering using steel H-piles for transferring overhead rail crane loading below the
consolidating layers at the site. We estimate that a W l2 x 58 steel pile will achieve an allowable axial load of
30 tons when driven to minimum tip elevations of 40 to 45 feet below existing surface grades. This allowable
axial load takes into account potential negative loading caused by dovmdrag on the pile due to consolidation of
the compressible layers under building fill and floor slab loading.
Full axial capacity can be used provided the piles are spaced at a minimum of three pile diameters. Closer
spacing in pile groups will require a reduction in the single pile capacity. This reduction will depend on the
number of piles in the pile group and the spacing used. For resistance to lateral loading, a lateral pile capacity
of four tons can be used. The estimated pile settlements are 1/4 inch and less, excluding settlement due to elastic
shortening of the pile itself.
Page No: 7
February 1, 1996
Project No. T-3064
The pile driving hammer used to install the piles should have sufficient energy to drive the piling to the estimated
tip elevation without damage to the pile. We also recommend that prior to ordering production piles and their
installation, a minimum of three test piles be driven at the site to verify anticipated tip elevations and establish
driving criteria for use in evaluating production pile capacities. The test piles should be driven with the same
•'" equipment that will be used in the production pile installations.
4.6 Rail Crane Foundation-Augercast Piling
Augercast piling can be considered as an alternative to steel piling in transferring rail crane foundation loading
below the consolidating layers at the site. For 16-inch diameter pilings with minimum tip elevations of 40 feet
below existing surface grades, an allowable axial load of 35 tons is available for design. This loading takes into
account the potential negative loading effects due to downdrag.
Similar reductions in pile capacity as those discussed above can be expected when piles are placed in groups.
For resistance to lateral loads, an allowable lateral pile capacity of four tons is available. The estimated pile
settlement is 1/4 inch and less.
Augercast piles are formed by the pressure injection of grout through a hollow stem auger which is slowly
retracted from the ground after advancement to the recommended tip elevation. The grout pressure used will
compress the soils within the immediate vicinity of the pile, thereby increasing to some extent the pile diameter
40 and the amount of grout required to construct the pile. For planning purposes, we suggest considering a 30
percent increase in the amount of grout necessary to form the pile.
In construction of agercast piling, a higher than normal reliance on quality Nvorkmanship is required for
successful installations. It is extremely important that the grout pressure is consistent and uniform during the
installation and that retraction of the auger occurs at a slow uniform pace beneath a sufficient head of grout in
the pile column. The contractor should have adequate means for verifying grout pressure and estimating the
volume of grout used in the construction of the piles. Because of the compression effects and the possible
influence on adjacent pile construction, the installation sequence should be based on a minimum pile spacing of
• five pile diameters. Once the grout column has achieved its initial 24 hour set, pile construction in between
these spacings can be completed.
4.7 Slab-on-grade Floors
With site preparation completed as described in the Site Preparation and Grading section, new structural fill
soils should be suitable for supporting slab-on-grade construction. Immediately below the floor slabs, we
recommend that an allowance be made for placing a six-inch layer of clean free-draining sand or gravel which
has less than five percent passing the No. 200 sieve. This capillary break will guard against wetting of the floor
slab due to the underlying soil conditions.
Where moisture via vapor transmission is not desired, a polyethylene vapor barrier should also be installed. We
suggest that this vapor barrier be placed on an initial four inch layer of the capillary break material and then
covered with the final two inches to help protect it during construction and to aid in uniform curing of the
concrete floor slab. For slab thickness design with respect to floor deflection due to traffic and point loadings, a
subgrade modulus of 300 pci (pounds per cubic inch) can be used.
Page No. 8
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• February 1, 1996
Project No. T-3064
Estimated floor slab settlements of less than 3/4 inch are expected due to post-primary consolidation. This
movement assumes that settlements due to required building fills would be allowed to occur prior to floor slab
construction. The floor movements would be entirely differential with respect to the foundation construction.
• 4.8 Excavations
Excavations greater than four feet in depth will need to be completed in accordance with local, state, or federal
�y regulations. In accordance with the Occupational Safety and Health Administration (OSHA), inorganic soils
encountered at the site would be classified as Group C soils. Accordingly, excavations made within the native
soils or fill at the site greater than four feet in depth but not exceeding 20 feet in depth will need to be laid back
with side slope gradients of 1.5:1. Due to the low strength characteristics of the on-site silty peat, we
recommend that excavations within this material be shored using a ditchbox or temporary bracing.
Optionally, the use of a trench shoring box to support excavations throughout the lower depth may be used in
conjunction with sloping of the upper portion of the excavation as outlined above. Dewatering of the excavation
will need to be considered where excavation depths exceed five feet below existing site grade.
•' 4.9 Utilities
We recommend that all site utilities be bedded and backfilled in accordance with applicable APWA
specifications. For site utilities within City rights-of-way, bedding and backfill should be completed in
accordance with City of Renton specifications. At a minimum, utility trench backfill should be placed and
compacted in accordance with recommendations presented in the Site Preparation and Grading section. Where
utilities vczll occur below unimproved areas, the degree of compaction can be reduced to a minimum of 90
percent of the soil's maximum density as determined by the referenced ASTM standard. Because of the
potential for long-term settlements, utility pipe joints and connections should be of flexible nature allowing for
up to one inch of differential movement.
4.10 Lateral Earth Pressures
The magnitude of earth pressure development on retaining walls constructed in loading dock areas will partly
depend on the quality of backfill. Where fill is placed behind retaining walls, we recommend placing and
compacting it as structural fill. The fill should be compacted to a minimum of 95 percent of its maximum dry
unit weight as determined by ASTM Test Designation D-698 (Standard Proctor). To guard against the build up
of hydrostatic pressure, wall drainage must also be installed as discussed in the drainage section.
With granular backfill placed and compacted as recommended and drainage properly installed, we recommend
designing restrained (not free to deflect) retaining walls for an at-rest earth pressure equivalent to a fluid
weighing 50 pcf. For unrestrained walls (free to deflect), this value may be reduced to 35 pcf. These values do
not include other surcharge loading such as adjacent footings or sloped backfill that may act on these walls. If
such conditions will exist, then the imposed loading must be included in the wall design. Friction at the base of
foundations and passive earth pressure will provide resistance to these lateral loads. Values for these
parameters are provided in the Foundations section of this report.
Page No.9
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• February 1, 1996
Project No. T-3064
4.11 Drainaze
Surface
Final exterior grades should promote free and positive drainage away from the building areas at all times.
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Water must not be allowed to pond or collect adjacent to foundations or within the immediate building area. We
-� recommend providing a gradient of at least three percent for a minimum distance of ten feet from the building
perimeter, except in paved locations. In paved locations, a minimum gradient of one percent should be provided
• unless provisions are included for collection and disposal of surface water adjacent to the structure.
Subsurface
In our opinion, perimeter foundation drains would not be necessary if the area immediately adjacent to the
structure is paved and positive surface drainage maintained. If the grade is not positively drained away from the
structure or is landscaped,perimeter foundation drains should be installed.
• To guard against hydrostatic pressure development, retaining wall drainage must be installed. We recommend
that wall drainage consist of a minimum 12-inch thick layer of washed rock or pea gravel placed adjacent to the
wall. A four-inch diameter perforated pipe should be placed on a bed of gravel at the base of the wall footing
and gravel drainage column. The pipe should be directed to a suitable outlet.
4.12 Pavements
With subgrade soils prepared as described in the Site Preparation and Grading section, suitable support for
pavement construction should be provided. HoNvever, regardless of the compaction results obtained, subgrades
1 must be in a stable non-yielding condition prior to paving. Immediately prior to paving, the area of the subgrade
should be proofrolled with heavy construction equipment to verify this condition.
The required pavement thickness is not only dependent upon the supporting capability of the subgrade soils but
also on the traffic loading conditions which will be applied. For light commercial vehicles and typical passenger
vehicle traffic the following pavement sections are recommended:
• Two inches of asphalt concrete (AC) over four inches of crushed rock base (CRB)
• Two inches of AC over two inches of asphalt treated base (ATB)
For heavy truck traffic areas, we recommend the following pavement sections:
• Three inches of AC over six inches of CRB
• Three inches of AC over four inches of ATB
• Page No. 10
• February 1, 1996
Project No. T-3064
If there is a potential that pavement construction will be delayed until the wet winter months, the subgrade soils
must consist of a clean granular materiat as described in the Site Preparation and Grading section. In addition,
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we strongly suggest that the subgrade be further protected by placing a layer of ATB on which construction
• traffic could access the project without excessively disturbing the subgrade soils. The ATB thickness for this
purpose should be four inches. Repair of failed ATB areas should be anticipated prior to final paving.
However, the overall integrity of the subgrade soils will be considerably less impacted with this protection
provided.
•E.i
• Because of secondary compression of the organic silt layer, some degree of post-construction settlement within
the pavement structure should be anticipated. This settlement will probably result in some longitudinal and
transverse cracking of the pavement. Cracks in the pavement should be sealed in a timely fashion to prevent
excessive surface water infiltration into the subgrade soils.
5.0 ADDITIONAL SERVICES
• Terra Associates, Inc. should review the final design and specifications in order to verify that earthwork and
foundation recommendations have been properly interpreted and incorporated in the project design. We should
also provide geotechnical services during construction in order to observe compliance with the design concepts,
i specifications, and recommendations. This will also allow for design changes if subsurface conditions differ
from those anticipated prior to the start of construction.
We request a minimum of two working days notice be given to schedule our services during construction.
6.0 LIMITATIONS
• We prepared this report in accordance with generally accepted geotechnical engineering practices. This report is
the property of Terra Associates, Inc. and is intended for specific application to the Farwest Steel project in
Renton, Washington. This report is for the exclusive use of Farwest Steel Corporation and their authorized
representatives. No other warranty, expressed or implied, is made.
• The analyses and recommendations presented in this report are based upon data obtained from the test borings
drilled on-site. Variations in soil conditions can occur, the nature and extent of which may not become evident
until construction. If variations appear evident, Terra Associates, Inc. should be requested to reevaluate the
recommendations in this report prior to proceeding with construction.
Page No. 11
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REFERENCE: THE THOMAS GUIDE, KING COUNTY, WASHINGTON, PAGES 655, 656, 685 AND 686, 1995 EDITION.
VICINITY MAP
NTERRA FARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
Geotechnicali Consultants Proj. No.3064 Date 1/96 Figure 1
S. W. 34th. STREET
• I
I
Pt iE Two
I �� B-1 ;225oAS tiR
! j I
o�
B-3
i i o
> I i
I B-5
i
B-4
B-2
LEGEND: REFERENCE:
APPROXIMATE BORING LOC/,TION SITE PLAN PROVIDED BY HORTON DENNIS AND
ASSOCIATES, INC., JOB No. UNKNOWN, SHEET
------ 10 ft. LANDSCAPE EASEMENT No. SB5.GCD, DATED 1/24/96.
ALONG STREET FRONTAGE
......... RAILROAD CENTERLINE
APPROXIMATE SCALE - PROPOSED RAILROAD CENT=RLINE
100 0 100 200 feet
EXPLORATION LOCATION PLAN
x TERRA FARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
@#Geotechnical Consultants Proj. No.3064 Dote 1/96 Figure 2
•
• STEEL ROD
PROTECTIVE SLEEVE
HEIGHT VARIES
SURCHARGE (SEE NOTES) SURCHARGE
�1 OR FILL OR FILL
•
•I
�a NOT TO SCALE
•
NOTES:
1. BASE CONSISTS OF 1/2" THICK, 2'x2' PLYWOOD WITH CENTER DRILLED 5/8" DIAMETER HOLE.
2. BEDDING MATERIAL, IF REQUIRED, SHOULD CONSIST OF CLEAN COARSE SAND.
3. MARKER ROD IS 1/2" DIAMETER STEEL ROD THREADED AT BOTH ENDS.
4. MARKER ROD IS ATTACHED TO BASE BY NUT AND WASHER ON EACH SIDE OF BASE.
5. PROTECTIVE SLEEVE SURROUNDING MARKER ROD SHOULD CONSIST OF 2" DIAMETER
• PLASTIC TUBING. SLEEVE IS NOT ATTACHED TO ROD OR BASE.
6. ADDITIONAL SECTIONS OF STEEL ROD CAN BE CONNECTED WITH THREADED COUPLINGS.
7. ADDITIONAL SECTIONS OF PLASTIC PROTECTIVE SLEEVE CAN BE CONNECTED WITH PRESS—FIT
PLASTIC COUPLINGS.
8. STEEL MARKER ROD SHOULD EXTEND AT LEAST 6" ABOVE TOP OF PLASTIC PROTECTIVE SLEEVE.
9. STEEL MARKER ROD SHOULD EXTEND AT LEAST 1' ABOVE TOP OF FILL SURFACE.
TYPICAL SETTLEMENT MARKER DETAIL
P# TERRA FARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
Geotechnicol Consultants Proj. No. 3064 Date 1/96 Figure 3
SLOPE 12:1(V:H) GEOTEXTILE FACING COMPACTED STRUCTURAL FILL
MINIMUM WRAP (typical) 95% MAX. DRY DENSITY t2%
OPTIMUM MOISTURE CONTENT
PER D-698 (STANDARD PROCTOR)
0.81-1 feet (TYPICAL) .
3 feet
(TYPICAL) ..
H feet
18 in. (max.) : .. ..
MIRAFI 5T
GEOGRID
:. (TYPICAL)
NOT TO SCALE
REINFORCED SOIL WALL SECTION
TERRA FARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants [Proj. No.3064 Date 1/96 Figure 4
APPENDIX A
FIELD EXPLORATION AND LABORATORY TESTING
•a Farwest Steel
Renton,Washington
On January 9 through 11, 1996, we performed our field exploration using a truck-mounted hollow stem
auger drill rig. We explored subsurface soil and groundwater conditions at the site by drilling six hollow
stem auger test borings to a maximum depth of 59 feet below existing grade. The test boring locations
are shown on Figure 2. Test hole elevations were interpreted from the USGS Renton Topographic
Quadrangle. The Boring Logs are presented on Figures A-2 through A-7.
An engineer from our office maintained a log of each test hole as it was drilled, classified the soil
conditions encountered, and obtained representative soil samples. All soil samples were visually
classified-in accordance with the Unified Soil Classification System shown on Figure A-1.
• Representative soil samples were obtained from the test borings using sampling procedures outlined in
ASTM Test Designation D-1586 (Modified Proctor). The samples were placed in jars or tubes (ring
• samples) and taken to our laboratory for further examination and testing. The moisture content of each
sample was measured and is reported on the Boring Logs. Plasticity characteristics of the fine-grained
soils were determined by conducting Atterberg limits tests. Consolidation tests were performed on
samples of the organic silt and silty clay obtained during drilling of Borings B-5 and B-6. Grain size
analyses were performed on eight of the samples. The results of the grain size analyses are presented as
• Figures A-8 through A-11.
Project No. T-3064
Boring No. B-1
Logged by: KPR
Date: 1/9/96 Approximate Elev. 12
Graph/ Q_ (N) Water
USCS Soil Description Relative Depth E Blows/ Content
Density (ft.) 0 foot N
Brown-gray gravelly medium sand
Sp
FILL cuttinps. saturated.
FILL: Dark gray silty SAND with
Very Dense
SM fine to medium grained,moist. 61 7.8
gravel,
FILL: Dark gray silty SAND with Y
Sp 5
few gravel,fine to medium Loose
X... 4 16.1
X
rained saturated.
saturated.
A A A A A A ft A A h A A I Dark brown PEAT,with some silt,
A I fibrous to amorphouse,wet to Medium Stiff 7 202.3
saturated. 7.5 to 9 feet dark
• 7 0 1 P T-A A brown PEAT,fibrous with silt,wet. — 10
A A A ft A 10 to 11.5 feet Dark brown silty Soft - 3 171.6
h A PEAT,fibrous to amorphouse,wet.
- - --------------------------------------------------------------------
Black SAND, medium-grained, = 24 25.1 Bentonite slurry
saturated, 4 inch thick layer Medium Dense - added to hole to
of brown, saturated, non- — 15 control heave.
plastic silt at.13 feet.
X.-
54 18.7
Black SAND, as above but
Very Dense
without silt layer and very dense.
—20
j;. 'Kn*
50+
Black SAND, as above. Very Dense 17.0
— 25
Black SAND, as above but Dense
;g finer grained. = 49 24.3
30
Z V:% Black SAND, medium grained,
saturated, interbedded with 4 Medium Dense
29 36.0
inch thick layers of brown, soft,
W
clayey silt. —35
Black SAND, medium-grained,
saturated.
SM I Dark gray silty SAND with shells, Medium Dense I 14 25.8
Nfine-grained, saturated.
• Test boring terminated at 39 feet.
Groundwater encountered at 4.5 feet.
Hole plugged with 3 bags of bentonite chips mixed with cuttings.
BORING LOG
. ........ TERRA FARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants Proj. No. T-3064 � Date 1/96 Figure A-
Boring No. B-2
Logged by: KPR
Date: 1/9/96
Approximate Elev. 12
m
Graph/ a (N) Water
h/
P Relative Depth E Blows Content
USCS Soil Description Density (ft.) o (ft) (%)
7 >' z`I'«> Brown SAND with few gravel
and silt fill cuttings, medium
grained, wet.
' SP-SM
FILL: Brown SAND with few
Dense 33 12.3
gravel, medium-grained,wet.
------------- - ------- ------- - ---
- --
Gray-brown-organic- -clayey-SILT- ,--- ---------------------- 5 LL=60
I low plasticity, saturated, 1 inch Medium Stiff
• ,�iii , � i�:ii P Y 8 64.0 PL=47
i i thick peat layer at 7.5 feet. PI=13
iiOHii
Gray-brown organic SILT
(as above). Medium Stiff
Black SAND with silt, very fine- Medium Dense 28 32.6
grained, saturated.
Test boring terminated at 9 feet.
Groundwater encountered at 4.5 feet.
Hole plugged with 1 bag of bentonite chips mixed with cuttings.
0
41
BORING LOG
TERRA FARWEST STEEL
ASSOCIATESRENTON, WASHINGTON
Geotechnical Consultants
Proj. No. T-3064 Date 1/96 Figure A-3
Boring No. B-3
Logged by: KPR
Approximate Elev. 12
Date: 1/10/96
Graph/ Relative Depth a (N) Water
USCS Soil Description p E Blows/ Content
Density (ft') ) foot N
Brown, medium rained sand Bentonite slurry
��`::>.•.::.. FILL cuttings with few gravel, added to hole
wet. to control heave
•a.Sy.Yn.::••:::A.::i:':
FILL: As above but saturated. Medium Dense 18 16.9
ove but gray. Loose
5
• i i i Dark brown organic SILT with peat
I I I I I I i l fibers,low plasticity,moist to wet. Soft =
ill Gray-brown clayey SILT,low plasticity LL=73
OH i i saturated,5 inch thick layer of
I I I I I I fibrous peat at 8 feet;black,fine- 5 69.1 PL=64
rained siltysand in sampler tip. Medium Stiff
PI=9
10
Dark gray, silty SAND, very
SM fine to fine-grained, saturated. Medium Dense
19 33.7
— 15
t:••v
• >:�' °`'` Black SAND, with thin interbeds
of dark gray silty SAND, fine Medium Dense 17 33.2
i :'•.. ;•. :% :<.::;:: to medium-grained, saturated.
20
;a
SM Dark brown-gray silty SAND, Medium Dense
S very fine-grained, saturated.
•:#;<::s::>: ::::� Black SAND, fine to medium- Medium Dense
::•;;;a;.x•�;•••>.•;:::: grained, saturated.
25
' .,gp_'<
Black SAND, as above. Dense 36 24.6
<:
Test boring terminated at 29 feet.
Groundwater encountered at 1.5 feet and 7 feet.
Hole plugged with 1 bag of bentonite chips mixed with cuttings.
BORING LOG
TERRA FARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants
Proj. No. T-3064 Date 1/96 Figure A-4
Boring No. B-4
Logged by: KPR
Date: 1/10/96 Approximate Elev. 12
Graph/ Relative Depth C- (N) Water
USCS Soil Description E Blows Content
Density (ft.) (ft) (%)
{•'>`� :�+:�:.• Brown, medium-grained sand
•<� .'s^�`. '.','•f'���.•.+•.�? FILL cuttings, wet.
Medium Dense
�• :: SP %' FILL: Brown SAND, medium.
grained, saturated. 27 13.6
y? +
{' w
IIIIIIIIIIII Ili Gray-brown organic SILT, low Medium Stiff 5 LL=70
I II I IIIII II I I II plasticity, wet, dark brown 6 60.8 PL=50
1I i IOH i ICI fibrous, wet peat in sampler P1=20
.
tip IIIII I I IIIII
I IIIIIIIIIiI III
II IIIIIIIII III Medium Stiff
IIIIII I 10 43.2
SM > <: Dark gray silty SAND,very fine Medium Dense
to fine-grained, saturated.
�i
a
BORING LOG
TERRA FARWEST STEEL
4 • ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants
Proj. No. T-3064 Date 1/96 Figure A-5
i
•
i Boring No. B-5
Logged by: KPR
� Approximate Elev. 12
Date: 1/11/96
• a)
i
Graph/ Cl (N) Water Relative Depth E Blows/ Content
USCS Soil Description Density (ft.) a foot N
<'•'{:`•':'`•"s<''.<'': Gray sand FILL cuttings with
few gravel, medium-grained,
.r. SP . .. moist.
SM
i FILL: Gray sand with silt and some Dense = 30 9.1
gravel, medium grained,wet to 3.5
feet becoming saturated.
i
Brown-gray organic SILT,with Stiff 5 LL=78
PL=54
peat fibers, saturated, low 10 71.0
i' i OH i i plasticity. PI=24
Gray clayey SILT, wet, low LL=53
plasticity. Soft 2 69.1 PL=35
Dark gray silty SAND, very fine PI=18
• to fine-grained, saturated. Loose 10 Bentonite slurry
added to hole
SM " to control heave
Dark gray silty SAND, as above. Dense
32 26.2
nn
>`w' Sava Black SAND, fine-grained, 15
saturated.
:+ ..• .:.
Black SAND, as above but with 37 29.2
> :•' '• occasional 1 inch thick silty Dense
> : :> very fine-grained sand layers. 20
Black SAND, medium rained,
•r�.�: .��;>:<:::>� g Very Dense
? ?��•:?::::,::: saturated.
—25
'"`"`j ?''??' Black SAND with silt fine-
. '' :>'si.;>•>>'' grained, saturated.
SP SM Very Dense
:•<?::; 52 25.5
Page 1 of 2
BORING LOG
` TERRA FARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants
Proj. No. T-3064 Date 1/96 Figure A-6
Boring No. B-5 (Continued)
• Logged by: KPR
Approximate Elev. 12
Date: 1/11/96
a)
Graph/ Relative Depth Q (N) Water
USCS Soil Description E Blows/ Content
Density (ft•) '3 foot N
Cn
• Gray silty CLAY,with trace
wood bits and clam shells,
low plasticity, saturated. Very Soft
ML 1 65.4 LL=45
CL
PL=24
Gray silty CLAY, with clam 35 e=PI=21
21
1.08
shells, low plasticity, saturated, Very Soft 1 48.2 C,=0.142
with sand at 36.5 feet.
Unit Wt.=107.3
- --------------------------------------- ---------- - -- - - pcf
Gray silty SAND, with clam
shells, medium-grained, 4 25.8
SM :XV
;:::: saturated. Loose
...... ....... 40 Increased drilling
:•.;. resistance at
. 40 feet
:•,fir;.r :.::
SP SM Black SAND with some silt, Dense 37 26.5
k....
:>, medium-grained, saturated.
. 4
Dark gray silty SAND/sandy
SILT with shells, very fine- Medium Dense 16 44.4
grained sand, saturated.
� 50
SM ML Dark gray silty SAND with T
occasional shells,very fine Medium Dense r I 11 35.4
to fine-grained and bits of --LL
wood, saturated.
55
• I Dark gray silty SAND, as above. Medium Dense
19 25.7
Test boring terminated at 59 feet.
Groundwater encountered at 3.5 feet.
Hole plugged with 2 bags of bentonite chips mixed with cuttings.
Page 2 of 2
i BORING LOG
FARWEST STEEL
TERRA
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants
� Proj. No. T-3064 Date 1/96 Fgure A-6
Boring No. B-6
• Logged by: KPR Approximate Elev. 12
Date: 1/11/96
0 a)
Graph/ 0- (N) Water
0 USCS Soil Description Relative Depth E Blows/ Content
Density (ft.) C3 foot (%)
• V CIO
Brown-gray, gravelly medium-
• grained silty sand FILL cuttings,
i�i� ��ii
saturated.
• S M FILL: Gray SAND with gravel, Dense
32 9.3
medium-grained, wet.
7.5 feet:
FILL: Gray SAND, medium- Loose 5 LL=80
grained, saturated. PL=34
3 62.9
Dark brown PEAT, amorphous,wet. Soft PI=46
------------------- e.=1.77
I
Gray sandy SILT,with clay,very fine- C,=0.467
grained sand,saturated,medium plastic. Soft MH 1 3 58.2 Unit Wt.=94.3
pcf
Gray silty SAND, very fine to Loose Bentonite slurry
fine-grained, saturated. 10
added to hole
to control heave
Dark gray silty SAND, very fine
to fine-grained, saturated,grades Medium Dense
to black sand in sampler tip. 19 28.7
'4
...........
.. . ......................
.............
15
. .........
. .........
Black SAND, fine to coarse-
g rained, saturated. Dense
..................................
33 21.5
......................
...............
:::::...............:.
......................
:.::.::..:...........::.
:::::::.:::::::....:::
..................
::. .::
20
--- ----------------------------------------- ------------------------
Black SAND, medium to coarse- very Dense
grained.
64 20.5
—25
Black SAND, as above. Very Dense
75 26.5
Page 1 of 2
0
BORING LOG
FARWEST STEEL
...... . TERRA
X ASSOCIATES RENTON, WASHINGTON
A A A
Geotechnical Consultants Proj. No. T-3064 Date 1/96 Figure A-7
LA
Boring No. B-6 (Continued)
� Logged by: KPR
Approximate Elev. 12
Date: 1/11/96
Graph/ Depth Q- (N) Water
USCS Soil Description Relative Dept
• Density ( E Blows/ Content
foot N
Black SAND, as above. Very Dense
54 22.6
' 35
Dark gray silty SAND with
• trace clam shells, fine to
medium-grained, saturated. Loose 7 25.1
sM 40
Dark gray silty SAND, as above.
• w::: ,sx:::s
58 29.8
trr{:
:c •� <••v• : : Dark gray SAND with silt,trace
SP-SM clam shells, very fine to fine- Very Dense
< grained, saturated. —45
i - --------------------------------------- -----------------------
XX
• Dark gray silty SAND,with trace Loose
bits of wood, clam shells and to 10 36.9
clay, very fine to fine-grained, Medium Dense
saturated. 50
S M
Dark gray silty SAND, as above. Loose 6 32.1
55
Dark gray silty SAND, as above. Medium Dense T
28 24.2
Test boring terminated at 59 feet.
Groundwater encountered at surface and 7 feet.
Hole plugged with 2 bags of bentonite chips mixed with cuttings.
Page 2 of 2
BORING LOG
TERRAFARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants
Proj. No. T-3064 Date 1/96 Figure A-7
SIEVE ANALYSIS HYDROMETER ANALYSIS
SIZE OF OPENING IN INCHES NUMBER OF MESH PER INCH, U.S. STANDARD GRAIN SIZE IN MM
N
\ CN
_
N \\\\ \ O O O O O O O •� M N O O CO O O O
F. 71T7cD 'd' N M M d• N d• c0 N O O O O O O O O O O O
100� NJ 0
90 10
(D
O
s � M 80 — - 20
o C/) X rn m
— O
o C7 D n 70 30 m
c 60 40 C7
m 50 -_ _ - - — - 50 �
m
cc) x
40 _- _ 60 M
�. = 30 - -- - -- 70 m
o - _
0 20 80
rn
70 G-)
rn ;;0 10 90
Z-rj D —
o —
Z 01 1 _ LJ100
m N O CI CD CD CD O O O OAD d
CO00 c ' t'') N ` 00 to d N- K) cV '—00 COcO • t7 00 to d• M cV
O O O CO W d- M N O O O O O O O O O O O CDD m GRAIN SIZE IN MILLIMETERS
COARSE FINE COARSE MEDIUM FINE
rn
z ILZ rn D COBBLES V AN FINES
---jr -<
0
Z C/) Boring or Depth Moisture
Key Test Pit (ft.) USCS Description Content (%) LL PL
CD 1 40B-1 2.5 SM silty SAND with gravel
0 B-1 37.5 SM silty SAND
SIEVE ANALYSIS HYDROMETER ANALYSIS
SIZE OF OPENING IN INCHES NUMBER OF MESH PER INCH, U.S. STANDARD GRAIN SIZE IN MM
N
N \\\\ \ O O O O O O O K) N Co Co O O O O
c0 d o N ntn .- r7 d CV d c0 N O O O O O O O O O O O
100 0
90 10
(D
0 —— -
0 80 - - 20
_. C/) ;a -D -
m
c� O D n 70 30 m
rn �
C D 60 40 n
�
z
M 50 - - 50
rn
W
40 - 60 CID
v m =
�. = 30 - - - 70 rn
0 20 80
rn
rn 10 90
z �_ -
o p� z CD -
Z 0 U100
CO
C rn - O O O O O O O O O 00 c0 d M CV —00 l0 st M CV '-"00 c0 d- n cV 300 c0 d M N
C CD CD
Co 00 t0 d r7 CV O O CD CD CoO O O O O O
co D rn GRAIN SIZE IN MILLIMETERS
=--I z I COARSE I FINE COARSE-F MEDIUM I FlNE
Z m D COBBLES V AN FINES
r— �
0
z Boring or Depth Moisture
Key Test Pit (ft.) USCS Description Content (�) LL PL
CD • B-2 2.5 SP—SM SAND with gravel and silt
O B-2 22.5 SP—SM SAND with some silt
SIEVE ANALYSIS HYDROMETER
SIZE OF O• •�
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Moisture
Description
silty SAND
• silty SAND with gravel
• WON On • ! • - * • 0 ! • 0 ;,• Llj 4k-! •_ -A -W, • • 0-V V • �
SIEVE ANALYSIS 7 HYDROMETER ANALYSIS
SIZE OF OPENING IN INCHES NUMBER OF MESH PER INCH, U.S. STANDARD GRAIN SIZE IN MM
CV
N \\\1-1 \ O O CD CDO O O M N O O O O O O
c0 iY r7 N MUl M d N d w N O O O O O O O O O O
t: 100� 0
't. 90 10
(D
0 —
rn 80 20
m
c� O D n 70 30 m
m
rt D 60 40 c�
50 — -- — — — -- - — 50 C/)
m
CD _ _ �;a
40 60 �
v m
�. G7 30 70 _m
= G-)
o --i
Wo 20 80
rn
.A
G7 —
m ;�a 10 90
Z-rt D_
o 0� Z
CDZ 0 _ 100
m N O O O O O O O O O 00 cO --0- tO N '— 00 c0 d M N 00 c0 d M cV 00 (0 d I-) cV
C CD Co O 00 cD 1-4- to CD O Co 0 O O O O O O O O
D-+ 'T' GRAIN SIZE IN MILLIMETERS
Z m D COBBLES
COARSE FlNE COARSE MEDIUM FlNE
GRAVELAN FINES
jr �
O
Z cn Boring or Depth Moisture
Key CD Test Pit (ft.) USCS Description Content (%) LL PL
D • B-6 37.5 SM silty SAND
0 B-6 52.5 SM silty SAND
1.10
1.05
i
j
•
�j 1.00
'! o
v
'o
>.95
• .90
of
0.85
.1 .5 1 5 10 50
Pressure (tsf)
Boring Depth is ur Dry,
Key USCS Soil Description Cc eo Density
No. (ft.) e ore After cf
• B-5 36.0 CL silty CLAY .14 .005 1.08 46.8 38.0 70.3
3 Cc = Virgin Compression Index
C� = Coefficient of Secondary Compression (at 0.83 tsf)
eo = Inploce Void Ratio
CONSOLIDATION TEST DATA
. 9# TERRA FARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
Geotechnical Consultants Proj. No.3064 TDote 1/96 Figure A-12
1.8 ,
1.7 i
• 1.6
O
>
1.5
• 1.4
• 1.3
.1 .5 1 5 10 50
Pressure (tsf)
Key Boring Depth USCS Soil Description Cc C. eo is ur 0 ns b
No. (ft.) Before A ter cf
• B-6 8.0 MH sandy SILT with clay .47 .0065 1.77 80.6 63.4 50.0
Cc = Virgin Compression Index
Q, = Coefficient of Secondary Compression (at 0.83 tsf)
eo = Inploce Void Ratio
CONSOLIDATION TEST DATA
9#Geotechnical
TERRA FARWEST STEEL
ASSOCIATES RENTON, WASHINGTON
Consultants Proj. No.3064 Date 1/96 Figure A-13