HomeMy WebLinkAboutStudies APPLICANT 4/8/2022M
Foundation Engineering, Inc.
Professional Geotechnical Services
Date:
July 17, 2013
To:
Jeff Jones, P.E.
Murray, Smith & Associates, Inc.
From:
Jon Huffman, P.E.
Subject:
South Hills Reservoir — Preliminary
Geotechnical Reconnaissance
Project:
SUB Reservoirs Seismic Analysis
FEI Project 2131028
We have completed the preliminary reconnaissance for the above -referenced project
location as part of the Springfield Utility Board (SUB) seismic analysis of various
reservoirs in Springfield, Oregon. This memorandum summarizes our observations
from a recent site visit, provides a discussion of local geology and anticipated seismic
hazards, and includes preliminary seismic design parameters to evaluate the existing
structure.
BACKGROUND
The South Hills Reservoir is a 1.5 MG, pre -stressed concrete tank supported on a
concrete ring foundation and interior column footings. The tank is accessed from a
gravel road off S. 66`5 Place, downhill (south) of the extension of Jessica Street
(Figure 1, attached). The tank was constructed in 1982. We understand there
have been no maintenance issues to date.
The structure is owned by SUB and is included as one of eight structures identified
by SUB and the Rainbow Water District (RWD) for seismic assessment, including
analysis for conformance with current Oregon Structural Specialty Code (OSSC)
standards and possible retrofit. Murray, Smith & Associates, Inc. (MSA) is the lead
designer for the project. Peterson Structural Engineers, Inc. (PSE) is the structural
consultant. Foundation Engineering, Inc. (FEI) was retained by MSA as the
geotechnical consultant. FEI's scope of work was outlined in a proposal dated
March 14, 2013, and authorized by a signed service agreement dated
May 14, 2013. A summary of our work for the other reservoir sites associated with
this project are included in separate memorandums.
LITERATURE REVIEW
Available geologic and seismic publications and maps were reviewed to characterize
the local and regional geology and evaluate relative seismic hazards at the site. The
literature review included geologic and seismic hazard studies completed in the
Springfield area by the Oregon Department of Geology and Mineral
Industries (DOGAMI) and other sources (Yeats et al., 1996; Black et al., 2000;
Hladky and McCaslin, 2006; Burns at al., 2008; McClaughry at al., 2010). Local
water well logs available from the Oregon Department of Water Resources website
were also reviewed; however, no logs were available proximal to the tank (T18S,
R2W, Sec 31.
820 NW Cornell Avenue • Corvallis, Oregon 97330 1 Bus. 1641) 757-7645 1 Fax 15411 757-7650
We also reviewed available design and construction documents. The documents
include as-built drawings (dated August 1982) prepared by the designer, CH2M Hill.
LOCAL GEOLOGY
Local geologic mapping indicates differing conditions at the reservoir site (Hladky
and McCaslin, 2006; McClaughry at al., 2010). Hladky and McCaslin (2006)
indicate that the site is underlain by landslide deposits (chaotic mix of soil and
rock). However, McClaughry at al. (2010) maps the site within volcaniclastic rocks
and tuff and the landslide deposits terminate to the north of the tank (downslope).
SITE RECONNAISSANCE
FEI accompanied SUB project manager, Bart McKee, P.E., on a site visit on
May 22, 2013, to observe the overall site conditions in the vicinity of the tank and
confirm the mapped geology. We also observed the condition of the exposed tank
foundations and ground conditions within the immediate vicinity of the tank to
determine whether foundation distress and/or ground settlement was evident, and
observed the surrounding property to look for evidence of past slope instability or
ongoing creep.
DISCUSSION OF SITE CONDITIONS AND RESERVOIR
The tank is sited on a relatively level bench within moderately sloping terrain. The
tank is south (uphill) of existing residential developments in a forested area primarily
vegetated with mature trees and dense underbrush. Survey data provided in the
as-built drawings indicates the bench existed prior to tank construction, but site
development included modest cuts and fills. The tank was constructed in a full cut
with a top of slab at ±EI. 953. Backfilling around the tank partially buried the
structure. The drawings indicate a finished grade of ±EI. 964 on the south side of
the tank and a finished grade of ±EI. 956 on the north side. The bench extends
±20 feet radially around the outside edge of the tank. North of the tank, the
ground slopes down at ±3:1 (H:V) and extends several hundred feet before
encountering existing developments. South of the tank, the ground slopes up
at ±2:1. An extension of Jessica Street is located uphill ±75 feet from the tank.
Ten test pits (TP-1 through TP-10) were dug in the vicinity of the tank as part of
the design phase and are documented in the as-built drawings. The test pits
excavated nearest to the tank (TP-5 and TP-7) and directly uphill of the tank (TP-6)
encountered basalt boulders in a silty clay matrix. This description is consistent
with landslide deposits. TP-5 through TP-7 extended to maximum depths ranging
from ±8 to 10.5 feet below the original grade, which is at most ±1 to 2 feet
below the foundation elevation.
A test pit dug north (downhill) of the tank encountered silty clay or silty clay with
siltstone pebbles in the upper t4 feet, followed by weathered siltstone extending
to the bottom of the test pit (±12 feet). Siltstone was not indicated in the other
test pits and the presence of siltstone is inconsistent with the mapped geology.
Available geologic maps indicate the nearby area is underlain by volcaniclastic rocks
SUB Reservoirs Seismic Analysis July 17, 2013
South Hills Reservoir Proiect 2131028
Preliminary Geotechnical Reconnaissance
Springfield, Oregon 2. Murray, Smith & Associates, Inc.
that include volcanic lithic clayey sandstone, unwelded lithic lapilli-ash tuff, and
tuffaceous polymictic pebbly mudstone (Hladky and McCaslin, 2006). We
anticipate the pebbly mudstone, when weathered, resembles weathered siltstone.
The extension of Jessica Street upslope from the tank was constructed by
excavating into the hillside along the south side of the street. The deepest portion
of the cut (±15 to 20 feet) exposes a thin mantle of soil over highly weathered tuff
or tuffaceous mudstone.
According to the as -built drawings, the tank foundations and slab are supported on
a minimum of 12 inches of compacted gravel extending to "undisturbed earth",
which we anticipate is the material described in the test pits (i.e., basaltic boulders
with silty clay). The depth to bedrock is expected to be relatively shallow based on
our site observations. However, the exact depth cannot be inferred from the design
drawings.
The perimeter ring foundation appears to be in relatively good condition with no
apparent cracking and/or settlement. We also did not observe conditions in the
surrounding area to indicate instability or slope creep. However, the thick
underbrush on the sloping terrain north and south of the tank currently obscures the
view of the slope surface (and any possible slumps). Furthermore, slope stability in
the vicinity of the tank remains a concern since the area is potentially underlain by
landslide deposits.
DISCUSSION OF POTENTIAL SEISMIC HAZARDS AND SEISMIC DESIGN
Seismic design parameters for the structures were established according to
OSSC (2010), which is based on the International Building Cade (IBC 2009).
Seismic Hazards
The OSSC (2010) Section 1803.7 requires the evaluation of risks from a range of
seismic hazards including: ground motion amplification, ground rupture, earthquake
induced landslides, liquefaction and lateral spread, and tsunami/seiche.
Investigations have been completed by DOGAMI to identify geologic and seismic
hazards in the Southern Willamette Valley (Black at al., 2000; Burns at al., 2008).
We have also developed conclusions regarding seismic hazards based our
knowledge of the site and local geology and recent site reconnaissance.
The relative earthquake hazard on the available maps is "based on the combined
effects of ground shaking amplification, liquefaction, and earthquake -induced
landslides" with a range in hazard from Zone A (highest hazard) to Zone D (lowest
hazard) (Black at al., 2000). The relative earthquake hazard in the vicinity of the
tank is mapped as Zone B (intermediate to high hazard) due to the tank being
potentially located in an area of historic landslide activity.
SUB Reservoirs Seismic Analysis July 17, 2013
South Hills Reservoir Pro am 2131028
Preliminary Geotechnical Reconnaissance
Springfield, Oregon 3. Murray, Smith & Associates, Inc.
Ground Motion Amplification. Ground motion amplification is the influence of a soil
deposit on the earthquake motion. As seismic energy propagates up through the
soil strata, the energy is typically increased (i.e., amplified) or decreased
(i.e., attenuated) to some extent. The DOGAMI map indicates the amplification
hazard at the site is low (Black at al., 2000; Burns et al., 2008). The tank is
underlain by variable soil of unknown thickness, followed by highly to moderately
weathered bedrock. Therefore, we believe the ground motion amplification is most
consistent with an OSSC/IBC Site Class C profile.
Liquefaction and Lateral Spreading. Liquefiable soils typically consist of loose, fine
sand and non -plastic or low plasticity silt below the ground water table. We do not
anticipate such soils are present based on the descriptions provided in the test pit
logs. However, confirmation of the consistency of the underlying soils will require
additional explorations. The relative liquefaction susceptibility map indicates a low
to moderate liquefaction potential (Burns at al., 2008).
Landslides and Earthquake -Induced Landslides. DOGAMI mapping indicates landslide
topography within the vicinity of the tank (Black at al., 2000). As a result, the
relative earthquake -induced landslide susceptibility is considered high to very high;
however, no existing landslides have been mapped at the tank location (Burns at
al., 2008). SLIDO and LIDAR viewers, available online through the DOGAMI website,
show the landslide features that are indicated on the Black at al. (2000) mapping
(DOGAMI, 2O13a; DOGAMI, 2013b).
The ground surface in the vicinity of the tank foundation appears to be stable with no
identifiable cracks or other surface features indicating ongoing movement. The tank
is also sited on a relatively wide bench with at least 20 feet of level terrain separating
the tank from the uphill and downhill slopes. Therefore, in its static condition and
without further alterations to the site, we anticipate the ground surface in the vicinity
of the tank is relatively stable with low potential for landslides. However, seismic
loads from the design -level earthquake may induce movement. The potential for an
earthquake -induced landslide should be investigated further to establish an estimate
of the likelihood and extent of such instability.
Ground Rupture. We anticipate the risk of ground rupture is low due to lack of
known faulting beneath the site. However, hidden and/or deep-seated active faults
could remain undetected. Additionally, recent crustal seismic activity cannot
always be tied to observable faults. In the event of a catastrophic earthquake with
a large seismic moment, inactive faults could potentially be reactivated.
Tsunami/Seiche. Tsunami inundation is not applicable since the site is not on the
Oregon Coast. Seiche (the back and forth oscillation of an enclosed or
semi -enclosed body of water during a seismic event) is also not a concern due to
the absence of large bodies of water near the site.
SUB Reservoirs Seismic Analysis
July 17, 2013
South Hills Reservoir
Project 2131028
Preliminary Geotechnical Reconnaissance
Springfield, Oregon 4.
Murray, Smeh &/associates, Inc.
Site Response
A spectral acceleration response spectrum for the reservoir site was established
based on IBC 2009/OSSC 2010 Section 1613. The design maximum considered
earthquake ground motion maps provided in IBC 2009 are based on the 2002 maps
prepared by USGS for an earthquake with a 2% probability of exceedence in
50 years (i.e., a ±2,475 -year return period). This information was obtained from
the USGS National Earthquake Hazard Mapping website.
A Site Class C is recommended for design based on the anticipated subsurface
profile. The seismic design parameters and response spectrum are presented on
Figure 2 (attached).
CONCLUSION
Based on the findings presented herein, we believe there are potential geologic
and/or seismic hazards that may require mitigation as part of any structural
improvements considered for the existing tank. Specifically, there is the potential
for an earthquake -induced landslide because the tank is located in an area of
historic landslide activity.
Estimating the likelihood and the magnitude of such hazards, as well as potential
mitigation options, will require further investigation of the subsurface conditions.
Therefore, we recommend drilling up to 3 exploratory boreholes in the vicinity of
the tank to identify the composition and depth of the soils and bedrock underlying
the site. We anticipate the borings would extend into the bedrock and samples
would be retained to characterize the overburden and the underlying rock. We
recommend drilling a boring on the north and south sides of the tank, and a third
boring further uphill (possibly on Jessica Street). The explorations will be used to
establish a cross-section of soil and rack conditions for slope stability analysis. A
site survey should also be completed (by others) to confirm the existing topography
for the analysis.
The site response spectrum (Figure 2) should be used as a preliminary means to
establish potential seismic acceleration forces on the structure. The site response
spectrum may be revised later based on the results from new explorations.
SUB Reservoirs Seismic Analysis
South Hills Reservoir
Preliminary Geotechnical Reconnaissance
Springfield, Oregon
5.
July 17, 2013
Noll 2131028
Murray, Smith & Associates, Inc.
REFERENCES
Black, G. L., Wang, Z., Wiley, T. J., Wang, Y., and Keefer, D. K., 2000; Relative
earthquake hazard map of the Eugene -Springfield Metropolitan Area, Lane
County, Oregon: Oregon Department of Geology and Mineral Industries,
Interpretive Map Series IMS -14, 16 p.
Burns, W. J., Hofmeister, R. J., and Wang, Y., 2008; Geologic Hazards, Earthquake
and Landslide Hazard Maas. and Future Earthauake Damaoe Estimates for Six
Polk Benton, Linn, and Lane Counties, and the City of Albany, Oregon:
Oregon Department of Geology and Mineral Industries, Interpretive Map
Series IMS -24, 50 p.
DOGAMI, 2O13a; LIDAR Viewer: Oregon Department of Geology and Mineral
Industries (DOGAMI), SUB Reservoirs Seismic Analysis, Springfield, Lane
County, Oregon, web site:
http://www.oregongeology.org/sub/lidardataviewer/index.htm, accessed
June 2013.
DOGAMI, 2O13b; SLIDO (Statewide Landslide Information Database for Oregon)
Viewer, SLIDO-2: Oregon Department of Geology and Mineral Industries
(DOGAMI), SUB Reservoirs Seismic Analysis, Springfield, Lane County,
Oregon, web site: http://www.oregongeology.com/sub/slido/index.htm,
accessed June 2013.
Hladky, F. R., and McCaslin, G. R., 2006; Preliminary Geologic Map of the
Springfield 7.5' Quadrangle, Lane County, Oregon: Oregon Department of
Mineral Industries, Open -File Report 0-06-07, 31 p.
Madin, I. P., and Murray, R. B., 2006; Preliminary Geologic Map of the Eugene East
and Eugene West 7.5' Quadrangles, Lane County, Oregon: Oregon
Department of Geology and Mineral Industries, OFR 0-03-11, 20 p.
McClaughry, J. D., Wiley, T. J., Ferns, M. L., and Madin, I. P., 2010; Digital
Geologic Map of the Southern Willamette Valley, Benton, Lane, Linn, Marion,
and Polk Counties, Oregon: Oregon Department of Geology and Mineral
Industries, Open -File Report 0-10-03, Scale: 1: 63,360, 116 p.
Yeats, R. S., Graven, E. P., Werner, K. S., Goldfinger, C., and Popowski, T. A.,
1996; Tectonics of the Willamette Valley, Oregon: in Roger, A. M., Walsh, T.
J., Kockelman, W. J., and Priest, G. R., ads., Assessing earthquake hazards
and reducing risk in the Pacific Northwest: U.S. Geological Survey,
Professional Paper 1560, p.183-222.
SUB Reservoirs Seismic Analysis July 17, 2013
South Hills Reservoir Project 2131028
Preliminary Geotechnical Reconnaissance
Springfield, Oregon 6. Murray, Smith & Associates, Inc.
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PROJECT NO.
2131028
FOUNDATION ENGINEERING INC. VICINITY MAP FIGURE NO.
PROFESSIONAL GEOTRCHNICAL BRRVICRB SOUTH HILLS RESERVOIR
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MGO. (6u) 767-M45 FAX c5.n "1-70570 Springfield, Oregon
FILE NAME:
0.5
0.4
0.3
0.2
0.1
tt
Response Spectrum
0 0.5 1 1.5 2 2.5 3
Period (seconds)
Notes:
1. The Design Response Spectrum is based on OSSC 2010 Section 1613 using the
following parameters:
Site Class= C Damping = 5%
Ss= 0.62 Fa= 1.15 Sms= 0.71 Sos= 0.48
Sr = 0.29 F, = 1.51 Sul = 0.43 Sm = 0.29
2. Ss and S, values for 5% damping are based on the USGS 2002 mapped maximum
considered earthquake spectral acclerations for 2% probability of exceedence in 50 years.
The corresponding peak ground acceleration on rock is 0.268.
3. F. and F„ were established based on OSSC, Tables 1613.5.3(1) and 1613.5.3(2)
using the selected Sc and Si values. Sos and Sol values include a 213 reduction on
Sms and Sun as discussed in OSSC 2010 Section 1613.5.4.
4. Site location is: Latitude 44.034, Longitude -122.909.
FIGURE 2.
OSSC 2010 SITE RESPONSE SPECTRUM
SUB Reservoirs Seismic Analysis - South Hills Reservoir
Springfield, Oregon
FEI Project 2131028
Foundation Engineering, Inc.
Professiowd Geotechnical Services
Date:
November 18, 2013
To:
Jeff Jones, P.E.
Murray, Smith & Associates, Inc.
From:
Jon Huffman, P.E., G.E.
James Maitland, P.E., G.E.
Subject:
South Hills Reservoir
Supplemental Geotechnical Investigatioi
Project: SUB Reservoirs Seismic Analysis
FEI Project 2131028-101
Be�N:(H:L4UPh
The Springfield Utility Board (SUB) is in the process of completing seismic analysis
of various reservoirs that include the 67'" Street, 70" Street and South Hills
Reservoirs in Springfield, Oregon. Murray, Smith & Associates, Inc. (MSA) is the
lead designer for the project. Peterson Structural Engineers, Inc. (PSE) is the
structural consultant. Foundation Engineering, Inc. (FEI) was retained by MSA as
the geotechnical consultant.
FEI's original work included preliminary geotechnical reconnaissance of the different
reservoir sites, the details of which are summarized in memorandums dated
July 17, 2013. Based on the results of the reconnaissance, FEI recommended
additional subsurface explorations and stability analysis be completed for the
above -referenced reservoirs. This recommendation was made primarily based on
each of the sites being located in an area of mapped landslide topography and
because of limited subsurface data. This memorandum addresses the South Hills
Reservoir. Our current scope of work was detailed in a proposal dated
August 21, 2013.
A vicinity map showing the location of the South Hills Reservoir is provided in
Figure 1A (Appendix A). Branch Engineering, Inc. (Branch) surveyed the reservoir
site. The surveyed site plan, including a layout of the existing steel tank, the
fenced area and gravel pad surrounding the tank, and the sloping terrain extending
±150 feet north (downhill) and ±120 feet south (uphill) from the tank is provided
in Figure 2A (Appendix A).
LOCAL GEOLOGY
Local geologic mapping from two sources provide differing conditions at the
reservoir site. Hladky and McCaslin (2006) indicate the site is underlain by
landslide deposits (chaotic mix of soil and rock). McClaughry at al. 12010) maps
the site within volcaniclastic rocks and tuff, with landslide deposits terminating
north of the tank (downslope). Our subsurface explorations indicate the tank site is
underlain by colluvium, more consistent with the mapping indicated by Hladky and
820 NW Ccrnell Avenue • Corvallis, Oregon 97330 • Bus. 15411 757-7645 • Fax 15411 757-7650
McCasin (2006). However, shallow bedrock (tuff and siltstone) was encountered
in our exploration (BH -1) located immediately upslope of the reservoir.
SUBSURFACE EXPLORATIONS
Borehole Explorations
Three exploratory boreholes (BH -1, BH -2 and BH -3) were drilled at the site on
October 9, 2013, using a truck -mounted, CME 75 drill rig with mud -rotary drilling
and HQ wire -line coring techniques. BH -1 was drilled upslope (southwest) of the
tank on Jessica Drive. BH -2 was drilled on the relatively level bench, ±18 feet
southwest of the tank. BH -3 was drilled in the gravel area, ±13 feet northeast of
the tank. The borehole locations are shown on Figure 2A (Appendix A).
The borings extended to maximum depths ranging from ±30.8 to 35 feet.
Disturbed samples were obtained in the borings in conjunction with the Standard
Penetration Test (SPT) at 2.5 -foot intervals to ±15 feet, then at 5 -foot intervals
thereafter. The SPT provides an indication of the density or stiffness of the soils.
Continuous, HQ -sized coring was completed in BH -1 from ±15 to 35 feet, once
competent bedrock was encountered.
The explorations were continuously logged during drilling. The final logs
(Appendix B) were prepared based on a review of the field logs, laboratory test
results, and an examination of the soil and bedrock samples in our office. Photos
of the rock core from BH -1 are also provided in Appendix B.
Previous Explorations
SUB provided as -built drawings (latest revision dated August 1982) prepared by
CH21VI Hill. Sheet 1 (Vicinity Map, Site Layout, Index to Drawings) and Sheet 2
(Test Pit Logs, Reservoir Excavation, Roadway Section) provide details of test pit
explorations completed as part of the original site development. The test pits range
in depth from ±5 to 12 feet. Where possible, these previous explorations were
used to supplement the current work. The referenced sheets are included in
Appendix A.
DISCUSSION OF SITE AND SUBSURFACE CONDITIONS
Site Lavout and Surface Conditions
The tank is sited on a relatively level bench within moderately sloping terrain. The
tank lies south (uphill) of existing residential developments in a forested area
primarily vegetated with mature trees and dense underbrush. Survey data provided
in the as -built drawings indicates the bench existed prior to tank construction, but
site development included modest cuts and fills. The tank was constructed in a full
cut with a top of slab at ±EI. 953. Backfilling around the tank partially buried the
structure. The recent survey by Branch indicates a finished grade of ±EI. 968 on
the south side of the tank and a finished grade of ±EI. 961 on the north side. The
SUB Reservoirs Seismic Analysis November 18, 2013
South Hills Reservoir
Supplemental Geotechnical Investigation Project 2131028-101
Springfield, Oregon 2. Murray, Smith & Associates, Inc.
bench extends ±20 feet radially around the outside edge of the tank. North of the
tank, the ground slopes down on average at ±3:1 (H:V) and extends a few
hundred feet before encountering existing developments. The ground slopes uphill
at a maximum of ±2:1 (H:V) south of the tank. An extension of Jessica Drive is
located uphill ±75 feet from the tank.
As noted in the previous memorandum (dated July 17, 2013), we did not observe
surface conditions in the surrounding area to indicate instability or slope creep.
There are also no apparent features typically associated with slope instability that
were identified from the topographic information included in the recent survey
(e.g., slumps or scarps). The perimeter ring foundation of the tank appears to be in
relatively good condition with no apparent cracking and/or settlement.
Subsurface Conditions
The borings encountered a subsurface profile that typically included the following
strata:
• Fill. Fill was encountered in BH -2 and BH -3, drilled adjacent to the tank. The
Fill is somewhat variable, consisting of sandy to silty clay and clayey silt with
trace gravel and scattered cobbles and boulders. The fill is similar in
consistency to the underlying colluvium and was likely generated from onsite
cuts during construction of the tank. Fill was encountered to ±B feet in
BH -2 and to ±7 feet in BH -3. Fill in BH -1 was limited to the pavement
section (i.e., asphalt and base rock).
• Colluvium. Colluvial soils, likely deposited from previous landslide activity,
were encountered in all three borings. The colluvium is variable, but
primarily consists of stiff to very stiff sandy clay to sandy silt or clayey silt
with trace to some gravel. Scattered cobble to boulder -sized rock fragments
were observed in BH -2. The variable nature of the material is typical of
colluvial soil. The colluvium was encountered in BH -1 beneath the
pavement, extending to ±7 feet. In BH -2 and BH -3, the colluvium was
encountered beneath the fill, extending to ±30 feet in BH -2 and to ±20 feet
in BH -3.
• Residual Soil. Residual soil consisting of very stiff clayey silt or sandy clay
was encountered beneath the colluvium in BH -1 and BH -3. The residual soil
represents bedrock that has decomposed in place to a soil -like consistency.
The residual soil was observed from ±7 to 10 feet in BH -1 and from ±20 to
25 feet in BH -3. The residual soil may also be present at BH -2, but too thin
to observe within the sampled material.
• Bedrock. Bedrock was encountered at ±10 feet in BH -1, at ±30 feet in
BH -2, and at ±25 feet in BH -3. The explorations encountered both tuff and
siltstone. However, the depth and location of the different rock types
appears to vary across the site.
SUB Reservoirs Seismic Analysis November 18, 2013
South Hills Reservoir
Supplemental Geotechnical Investigation Protect 2131028-101
Springfield, Oregon 3. Murray, Smith is Associates, Inc.
In BH -1, extremely weak (RO), decomposed tuff was encountered from
± 10 to 15 feet, followed by extremely weak (R0), decomposed siltstone.
The siltstone becomes highly to moderately weathered below ±20 feet, and
very weak (R1) and slightly weathered to fresh below ±25 feet. Coring the
siltstone from ±25 to 35 feet indicated very close to moderately close,
planar to irregular, rough, open jointing. ROD values in the rock core ranged
from ±82 to 90 percent.
In BH -2, extremely weak (RO), slightly weathered siltstone was encountered
from ±30 to 30.8 feet (the bottom of the boring). Drilling at 3H-3
encountered extremely weak (RO), decomposed to highly weathered tuff
from ±25 to 31.5 feet (the bottom of the boring).
The test pit logs provided in the as -built drawings typically describe silty clay with
basalt boulders or basalt boulders in a silty clay or silty sand matrix. From the
description and depths indicated in the logs, we expect these soils are consistent
with the colluvium encountered in the recent borings. TP -4 indicated weathered
siltstone from ±4 to 12 feet. No further description of the siltstone was provided.
Ground Water
Mud -rotary drilling precluded an accurate measurement of the ground water in the
borings at the time of drilling. However, a one -inch inside diameter (I.D.) standpipe
piezometer was installed in 13H-2 to a depth of ±25 feet. The piezometer is slotted
from ±15 to 25 feet to monitor ground water fluctuations. The installation was
capped at the ground surface with a Morris monument set in concrete. After
installation, the boring was bailed to remove the drilling fluid, then allowed to
recharge over a period of several days before measuring. Ground water
measurements taken on October 16 and November 7, 2013 are summarized in
Table 1.
Table 1. 1311-2 Piezometric Summary
Date
Water Depth
(feet)
Water Elevation
(feet)
10/16/13
23.2
944.5
11/7/13
16.0
951.7
The lower ground water reading (±23.2 feet) was taken during a period of
relatively dry weather, while the higher ground water reading (±16 feet) was taken
after several days of moderate rain. The available data suggests a significant rise
in the water table can occur in response to moderate rainfall.
SUB Reservoirs Seismic Analysis November 18, 2013
South Hills Reservoir
Supplemental Geotechnical Investigation Project 2131028-101
Springfield, Oregon 4. Murray, Smith & Associates, Inc.
LABORATORY TESTING
Laboratory testing included an Atterberg limits test on sample SS -3-4, the results
of which are summarized in Table 2. Natural water content determinations were
completed on most of the samples, and the results are included in the boring logs
(Appendix B).
Table 2. Summary of Atterberg Limits Tests
Sample
Number
Sample
Depth (feet)
Natural Water
Content (percent)
LL
PL
PI
USCS
Classification
SS -3-4
10 - 11.5
58.4
85
48
37
MH
ENGINEERING ANALYSIS
Seismic Design Parameters
The Preliminary Geotechnical Reconnaissance memorandum for the South Hills
Reservoir (dated July 17, 2013) provided design parameters that included a
spectral acceleration response spectrum based on IBC 2009/OSSC 2010
Section 1613. A Site Class C was recommended for preliminary evaluation of the
site. The results from the explorations confirm the recommended site class. For
completeness, the response spectrum is provided in Figure 3A (Appendix A).
Liquefaction and lateral spread were indicated as potential concerns based on
current hazard mapping (Burns et al., 2008)• However, the recent explorations did
not encounter liquefaction -susceptible soils (e.g., loose, fine sand and non -plastic or
low plasticity silt below the ground water table). Therefore, we believe the risk for
these hazards is very low.
Slope Stability Analysis
Slope stability analysis was completed to address potential instability concerns due
to the reservoir's location within mapped landslide topography. Both static and
seismic conditions were analyzed. A factor of safety (FS) of at least 1.5 is
typically required for static conditions where slope stability can affect a critical
facility. A FS of at least 1.0 is typically required for seismic conditions.
Two cross-sections of the reservoir site were examined for the analysis. The
locations of the cross-sections (designated as A -A' and B -B') are shown on
Figure 2A (Appendix A). They were developed based on the topographic data
obtained from Branch's survey and subsurface data from the explorations.
Cross-section A -A' is shown on Figure 4A and cross-section B -B' is shown on
Figure 5A (Appendix A).
SUB Reservoirs Seismic Analysis November 18, 2013
South Hills Reservoir
Supplemental Geotechnical Investigation Project 2131028-101
Springfield. Oregon 5 • Murrey, Smith & Associates, Inc.
Strength parameters for the different soil units identified in the cross-sections were
estimated from available correlations based on SPT N -values, laboratory tests, and
visual classifications. Typical strength tests (e.g., direct shear or triaxial shear)
were not practical based on the variable nature of most of the soils encountered in
the explorations. The assumed strength parameters of the different soil units are
indicated on the cross-sections. Strength parameters were assigned to the
colluvium, residual soil and bedrock, as well as a thin section at the interface of the
colluvium and residual soil. Previous movement is expected to have occurred along
this interface and, therefore, residual strength parameters were assumed. Strength
parameters were not assigned to the fill surrounding the tank since this material is
limited in extent. The strength parameters vary slightly for static and seismic
conditions. That is, an apparent cohesion (c1 was included for the colluvium and
residual soil to account for the soil response to dynamic loading conditions.
Ground water conditions for the analysis were based, in part, on the ground water
measurements from the piezometer in BH -2 and an estimation of the upper -bound
and average ground water levels. Based on the site conditions and ground water
measurements taken to date, we do not anticipate ground water flow that would
provide a hydrostatic pressure head above the phreatic surface. Therefore, for
static conditions, ground water was assumed at ±10 feet below the ground
surface at BH -2, with phreatic conditions approximately matching the estimated
ground surface and bedrock contours. We believe this represents an upper -bound
condition. For seismic modeling, the ground water was assumed at t 15 feet
below the ground surface at BH -2, again with phreatic conditions approximately
matching the estimated ground surface and bedrock contours. We believe this
represents an average ground water condition during wet weather.
Seismic conditions were simulated using pseudo -static analysis with a design
horizontal acceleration coefficient (kh) of 0.16. kh was estimated as one-half of the
maximum design ground surface acceleration (As), which was calculated based on
the peak bedrock acceleration of 0.26g from Figure 3A and a multiplying coefficient
(FMA) of 1.2, assuming a Site Class C soil classification.
The program SL/DE 5.0 was used to complete the two-dimensional stability
analysis. Stability methods including Spencer, Janbu and Bishop were used in
conjunction with circular and block failure modes. The circular failure search was
allowed for all depths, while the block failure search was limited to the zone
extending beneath the tank and assumed a failure surface through the interface
between the colluvium and residual soil. A nominal uniform pressure of 2,000 psf
was applied on the ground surface within the footprint of the tank to represent the
load imparted by the tank (this load did not affect the results of the analysis). The
output from the analysis is included in Appendix C.
The results for static conditions indicate a relatively low FS for the circular failure
mode, but only at very shallow depths on the steepest portions of the slopes.
These potential failure surfaces are not a significant concern because 1) they do
not extend beneath the existing tank and 2) are likely artificially low since the
SUB Reservoirs Seismic Analysis November 18, 2013
South Hills Reservoir
Supplemental Geotechnical Investigation Protect 2131028-101
Springfield, Oregon 6. Murray, Smith & Associates, Inc.
analysis does not take into account factors that include higher frictional resistance
at low confining stress and shallow root systems which provide additional
stabilization. The results indicate FS greater than 1.5 for circular failure surfaces
extending beneath the tank. FS greater than 1.5 were also indicated for block
failure surfaces extending beneath the tank and through the interface between the
colluvium and residual soil. FS greater than 1.0 were indicated for seismic
conditions.
Foundation Anafvsis
Bearing Capacity. We estimated the bearing capacity of the existing tank
foundations assuming the strength properties of the colluvium encountered in BH -2
and BH -3. Consistent with the slope stability analysis (seismic condition), we
assumed an effective angle of internal friction 1¢') of 28 degrees and an effective
cohesion 1c') of 200 psf.
Our calculations indicate a nominal bearing capacity of 9,000 psf. This results in
an allowable bearing pressure of 3,000 psf with a typical factor of safety of 3. A
one-third increase in the allowable bearing pressure (i.e., 4,000 psf) may be used in
evaluating short-term seismic loads.
Settlement. Any settlement due to soil consolidation from existing structural loads
has already occurred. Therefore, any additional settlement would be due to
mobilization of additional bearing resistance for short-term loads (e.g., seismic
loads). Settlement from such conditions is expected to be less than Y2 -inch.
Sliding Coefficient. The as -built drawings indicate the tank foundations are
underlain by 12 inches of compacted granular backfill. A coefficient of friction of
0.45 is appropriate for evaluating the sliding resistance between the concrete
footings and the underlying granular fill.
SUMMARY AND CONCLUSIONS
The slope stability analyses indicate the reservoir site is relatively stable for both
static and seismic conditions based on the estimated soil strength parameters.
Therefore, we believe the risk of slope instability is low.
Certain factors could still affect the stability of the site, including future
development of the surrounding area and other factors that influence ground water
conditions. In addition, as with any development within landslide terrain, some risk
of instability, though minor, still remains.
VARIATION OF SUBSURFACE CONDITIONS, USE OF THIS REPORT AND WARRANTY
The analysis, conclusions and recommendations contained herein are based on the
assumption that the subsurface profiles and ground water encountered in the
exploratory borings and the test pit records provided in the existing as -built
drawings are representative of the overall site conditions. No changes in the
SUB Reservoirs Seismic Analysis November 18, 2013
South Hills Reservoir
SupplamaMal Geotechnical Investigation Project 2131028-101
Springfield, Oregon 7, Murray, Smith & Associates, Inc.
enclosed recommendations should be made without our approval. We will assume
no responsibility or liability for any engineering judgment, inspection or testing
performed by others.
This report was prepared for the exclusive use of Murray, Smith & Associates, Inc.
Springfield Utility Board, and other design consultants for the South Hills Reservoir
as part of the SUB Reservoirs Seismic Analysis project in Springfield, Oregon.
Information contained herein should not be used for other sites or for unanticipated
construction without our written consent. This report is intended for planning and
design purposes. Contractors using this information to estimate construction
quantities or costs do so at their own risk. Our services do not include any survey
or assessment of potential surface contamination or contamination of the soil or
ground water by hazardous or toxic materials. We assume that those services, if
needed, have been completed by others.
Our work was done in accordance with generally accepted soil and foundation
engineering practices. No other warranty, expressed or implied, is made.
REFERENCES
Burns, W. J., Hofmeister, R. J., and Wang, Y., 2008;
Albany, Oregon: Oregon Department of Geology and Mineral Industries,
Interpretive Map Series IMS -24, 50 p.
Hladky, F. R., and McCaslin, G. R., 2006; Preliminary Geologic Map of the
Springfield 7.5' Quadrangle, Lane County, Oregon: Oregon Department of
Mineral Industries, Open -File Report 0-06-07, 31 p.
McClaughry, J. D., Wiley, T. J., Ferns, M. L., and Madin, I. P., 2010; Digital
;ounties, Oregon: Oregon Department of Geology and Mineral
Open -File Report 0-10-03, Scale: 1: 63,360, 116 p.
OSSC, 2010; Oregon Structural Speciality Code (OSSC1: Based on the International
Code Council, Inc., 2009 IBC, ISBN: 978-1-58001-955-2.
SUB Reservoirs Seismic Analysis November 18, 2013
South Hills Reservoir
Supplemental Geotechnical Investigation Project 2131028-101
Springfield, Oregon 8• Murray, Smith & Associates, Inc.
AhL
Profewoos!
C�=Aww
semc�
Appendix A
Figures
Foundation Engineering, Inc.
FOUNDATION ENGINEERING INC. VICINITY MAP FIGURE NO.
PROM31ONAL GEOTECHNICAL EERVICM SOUTH HILLS RESERVOIR
= NN COR11®L ANPx16 1 A
CW=S.. OR 9r 45I> SUB Reservoirs Seismic Analysis
eus (saq 757-7640 rex (wA ve 1... Springfield, Oregon
FILE NAME:
1!
�Y
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r
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sir
r I
•
rcE
-
SITE.
-
SCALE
DATE J�Po 2!113
DWN..1GYL—
Feef
APPR.-
0
3,100
6,200
12,400
RENS.
PROJECT NO.
2131028
FOUNDATION ENGINEERING INC. VICINITY MAP FIGURE NO.
PROM31ONAL GEOTECHNICAL EERVICM SOUTH HILLS RESERVOIR
= NN COR11®L ANPx16 1 A
CW=S.. OR 9r 45I> SUB Reservoirs Seismic Analysis
eus (saq 757-7640 rex (wA ve 1... Springfield, Oregon
FILE NAME:
w N
w
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rlE
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om W=�N6
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=,
0.5
0.4
0.3
0.2
0.1
OSSC 2010
Response Spectrum
0 0.5 1 1.5 2 2.5 3
Period (seconds)
Notes:
1. The Design Response Spectrum is based on OSSC 2010 Section 1613 using the
following parameters:
Site Class= C Damping = 5
Ss= 0.62 Fa= 1.15 See= 0.71 Sos= 0.48
S, = 0.29 F,. = 1.51 SM, = 0.43 Sol = 0.29
2. Ss and S, values for 5% damping are based on the USGS 2002 mapped maximum
considered earthquake spectral acclerations for 2% probability of exceedence in 50 years.
The corresponding peak ground acceleration on rack is 0.26g.
3. F. and F„ were established based on OSSC, Tables 1613.5.3(1) and 1613.5.3(2)
using the selected Ss and S, values. Sea and Sot values include a 213 reduction on
SMs and Su, as discussed in OSSC 2010 Section 1613.5.4.
4. Site location is: Latitude 44.034, Longitude -122.909.
FIGURE 3A.
OSSC 2010 SITE RESPONSE SPECTRUM
SUB Reservoirs Seismic Analysis - South Hills Reservoir
Springfield, Oregon
FEI Project 2131028
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Geotechnical
Smices
Appendix B
Boring Logs and
Rock Core Photos
Foundation Engineering, Inc.
DISTINCTION BETWEEN FIELD LOGS AND FINAL LOGS
A Held log is prepared for each boring or test pit by our field representative. The log contains information concerning
sampling depths and the presence of various materials such as gravel, cobbles, and fill, antl observations of ground water
It also contains our interpretation of the all conditions between samples. The final logs presented in this report
represent our interpretation at the contents of the field logs and the results of the laboratory examinations and tests.
Our recommendations ore based on the contents of the final logs and the information contained therein and act on
the field logs.
VARIATION IN SOILS BETWEEN TEST PITS AND BORINGS
The final log and related information depict subsurface conditions only at the specific location and on the date indicated.
Those using the information contained herein should be aware that soil condillons at other locations or on other dates
may differ, Actual foundation or subgrade conditions should be confirmed by us during construction.
TRANSITION BETWEEN SOIL OR ROCK TYPES
The lines designating the interface between soil, fill or rock on the final logs and on subsurface profiles presented in the
report are determirsd by iaterpalotian and are therefore opproximote. The transition between the materials may be
abrupt or gmduol. Only at boring or lest pit locations should profiles be considered as reasonably accurate and then
only to the degree implied by the notes thereon.
SAMPLE OR TEST SYMBOLS
SH -3-4
Sample Number S - Grob Samples
Boring ar Test Pit Number SS - Standard Penetration Test Sample (split -spoon)
Sample Type SH - Tlea,olled Shelby Tube Sample
C - Core Sample
Tap of Sample Attempt CS - Continuous Sample
Recovered Portion A Standard Penetrotioa Test Resistance equals the number
Unrecovered Portion (large of blows a 140 Ib weight lalling 30 in. is required to drive
circle Indicates no recovery) a standard sp6l-spoon sampler 1 ft. Practical refusal h
—Bottom of Sample Attempt equal to 50 or more blows Per 6 in. of sampler penetration.
• Water Content (R).
UNIFIED SOIL CLASSIFICATION SYMBOLS FIELD SHEAR STRENGTH TEST
G - Gravel W — Well Graded Shear strength measurements on lest pit side
5 - Sond P - Poorly Graded wolfs, blocks of soil or Shelby lube samples
M - Silt L - Low Plasticity are typically made with Torvone or pocket
C - Cloy H - High Ploslieily penetrometer devices.
Pt - Peat 0 - Organic
r
TYPICAL SOIL/ROCK SYMBOLS
1
Sond Silt
®
C®
Clay ;o_q Grovel
LaJ
80solt sAstone
WATER TABLE
d Water Table Location
(1/31/00)
Dole of Measurement
fJ
Piezometer Tip Location (If used,
vROPE25 A1011AL ION Em t�sNHNrcRiNS lcrs SYMBOL KEY
pYOPew"M° . BORING AND TEST PIT LOGS
eDFV— ae Ir.a0-1519
M. (so) 9 wa, FAX tel) '/dv-teea
Explanation of Common Terms Used in Soil Descriptions
Undrained shear strength
Term
Cohesive Soils
Granular Soils
Field Identification
Damp
Soil has moisture, Cohesive soils are below plastic limit and usually moldable,
SPT
Si," (tsf)
Term
SPT
Term
Visible water on larger groin surfaces. Sand and cohesionless silt exhibit dilatoncy.
Easily penetrated several inches
0 - t
< 0-125
Very Soft
0 - 4
Very Loose
by fist.
High Plasticity
>
30
Easily rolled and
reralled into thread.
Easily penetrated several inches
2 - 4
0.125-0.25
Soft
5 - 10
loose
by thumb.
Con be penetrated several inches
5 - B
0.25 - 0.50
Medium Stiff
11 - 30
Medium
by thumb with moderate effort.
(F Frm)
Dense
Readily indented by thumb but
9 - 15
0.50 - 1.0
Stiff
31 - 50
Dense
penetrated only with great effort.
Readi!y indented b lhumbnoil.
16 - 30
1.0 - 2.0
Ver Stiff
> 50
Very Dense
Indented with difficulty by
31 - 60
> 2.0
Hard
fhambnail.
1
1
Undrained shear strength
Term
Soil Moisture Feld Description
Dry
Absence of moisture. Dusty. Dry to the touch.
Damp
Soil has moisture, Cohesive soils are below plastic limit and usually moldable,
0
Grains appear darkened, but no visible water. Silt/clay will clump. Sand will bulk. Soils
Moist
are often at ar near plastic limit.
Wet
Visible water on larger groin surfaces. Sand and cohesionless silt exhibit dilatoncy.
- 15
Cohesive silt/clay can be readily remolded. Soil leaves wetness on the hand when
Medium Plasticity
squeezed. "Wet" indicates that the soil is welter than the optimum moisture content and
- 30
above the plastic limit.
Term
Soil Structure Criteria
Pi
Alternating layers at least 1 inch
Plasticity Field Test
Nonplastic
0
- 3
Cannot be rolled
into a thread.
Low Plasticity
3
- 15
Con be rolled into a thread with some difficulty.
Medium Plasticity
15
- 30
Easily rolled into
thread.
High Plasticity
>
30
Easily rolled and
reralled into thread.
Term
Soil Structure Criteria
Stratified
Alternating layers at least 1 inch
finger
thick - describe variation.
Laminated
Alternating layers at less than
Moderate
1 inch thick - describe variation.
Fissured
Contains shears and partings
pressure.
along planes of weakness.
Slickensides
partings appear glossy or striated.
Blocky
Breaks into lumps - crumbly.
Lensed
Contains pockets of different soils
- describe variation.
Term
Soil Cementation Criteria
Weak
Breaks under light
finger
pressure.
Moderate
Breaks under hard
finger
pressure.
Strong
Will not break with
finger
pressure.
FOUNDATIONaEtIflicZaNS
w00i COMMON TERMS
°ep n LeM°A'An SOIL DESCRIPTIONS
fa".. ae .-.All
&16 (Sal 13f-1615 PAX (.0 lbr-IGSY
Explanation of Common Terms Used in Rock Descriptions
Field Identification
(meters)
UCS (psi)
UCS (MPa)
Strength
Bedding/Foliation
<
006
< 2
(Hardness)
Indented by thumbnail.
RO
< 100
0.25-1.0
Extremely Weak
I fl.
Close
Thin
0.30
(Extremely Soft)
Crumbles under firm blows with geologicalVery
Rt
100-1000
1.0-5.0
Weak
hammer, can be peeled by a pocket knife.
3 ft. -
10 It.
Wide
(Very Soft)
Co. be peeled by a pocket knife with difficulty, shallow
R2
1000-4000
5.0-25
Weak
indentations mode by firm blow with geological hammer.
(Soft)
Cannot be scraped or peeled with a pocket knife, specimen
R3
4000-8000
25-50
Medium Strong
can be fractured with a single blow of geological hammer.
(Medium Hand)
Specimen requires more than one blow of
R4
8000-16000
50-100
Strong
geological hammer to fracture it,
(Hard)
Specimen requires many blows of
RS
16000-36000
100-250
Very Strong
geological hammer to fracture il.
(Very Hard)
Specimen can only be chipped with
R6
> 36000
> Y50
Extremely Strong
geological hammer.
(Extremely Hard)
Spacing
(meters)
Spacing
(feet)
Spacing Term
Bedding/Foliation
<
006
< 2
in
Very Close
Very Thin
0O6
- 0.30
2 in -
I fl.
Close
Thin
0.30
- 0.90
1 ft. -
3 ft.
Moderately Close
Medium
0.90
- 3.0
3 ft. -
10 It.
Wide
Thick
>
3.0
> 10
ft.
Very Wide
Very Thick (Massive)
Vesicle Term I Volume
%
Stratification Term Description
Lamination <0.39 in, thick beds
Some 3 - 20&
Fissile Preferred break along lomingtigns
Highly 20 - 509
Porting Preferred break direction
Scoria > 50%
Foliation Metamorphic layering of minerals
25 -
ROD
%
Designation
ROD X
Designation
0 -
25
Very Poor
75 - 90
Good
25 -
50
Pao,
90 - 100
Excellent
50 -
75
Fair
Rock Duality Oesignafon (R00) is the percent
Of a core run with intact lengths greater than
4.0 in. excluding breaks caused by drilling.
QROe�IONAL GEEOTDCNHNICAL SSERiVCES COMMON TERMS
°"0 NXC0pN°•"` ROCK DESCRIPTIONS
meveus, oa aron-'sr'
ei9. full 'et'.. PAC (earl M-nuir
Depth
Soil and Rock Description
Eley.
♦ SPT, • Moisture,
Installations/
and
Lob
Samples
N-VRevalue
Feat
Comments
Depth
O Recovery ® ROD.,
Water Table
98263
0 co 100
ASPHALTIC CONCRETE, (t5 inches). .
Capped with
1
_ _ _ _
Dense CRUSHED GRAVEL, (37 inches); grey, damp, I
.
0.4AC
9916
2
131-mch minus, (base rock). J
".
t0
patch and
_
Stiff sandy CLAY to sandy SILT, trace gravel; brown,
♦2
grevel
3
iron and manganese-stained, damp to moist, medium
sst4
Backfilled
4
plasticity, fine to coarse sand, fine, subangular gravel,
Win
(colluvium).
bentonite
5
59-1-2
Al
•
chips
6
7
-- ------------
seat
-
a
Verystiff dayey SILT; light grey, Iron and
7.0
♦.
•
8
manganese-stained, damp, medium plasticity,
531-3
24
(residual soil).
9
10
------ ------ ------
952.5
•:..:
Extremely Weak(RO) TUFF; light grey, ironstainetl
10.0
55-14
64
11
decomposed to consistency of hard sill
12
1
•..
13
i"./
S&I-5
66
F
14
15
__ _____
977.6
•
EMremely weak (RO)sandy SILTSTONE: grey to
15.0
5S16
16
brown, Ironstalned, decomposed, fine to coarse sand
_
_
17
18
19
_
20
Becomes blue-grey and high to moderately weathered
SS-1-7
5
21
below 320 feet.
_
-
22
_
23
—_
24
25
Becomes very weak(R1), slightly weathered to fresh
SS14
_?3-
26
below 325 feet
—
C31-1
Very dose to moderately dose, planar to Irregular,
27
rough, open jointing.
28
—_
29
0
30-
31
31
—_
32
_
33
34
35
=—Z
957.6
BOTTOM OF BORING
35.0
Project No.: 2131028-101 Boring Log: BH-1
Surface Elevation: 992.6 feet (Approx.) Springfield Utility Board (SUB)
Date of Boring: October 9, 2013 South Hills Reservoir
ARh Foundation Engineering, ITIC. Springftefd, Oregon
pie, or,
Depth
Soil and Rock Description
Elev.
♦ SPT, • Moisture, %
Inslallationsl
and
Samples
N -Value
Feet
Commends
Dem
El Recovery ® ROA.,%
Water Table
967.7
0 W 100
Soft to medium stiff silty CLAY to clayey SILT, some
0.0
Moms
1
and. trace to some gravel, scattered rubbles and
monument
boulders; brown to red -broom, iron and
set in
2
mangaoaseatained. moist, medium plasticity, fine to
A Is
-
concrete
3
coarse, subangulargravel, (fill).
sS24 :5'.
Bentonite
q
chips
5
662-2 '..
3
6
nch I.D.
]
PVC
8
_
0507
SS2J
- 6
1
"
harayey SILT, soma sand, trace to
Very stili to d cl
8.0
9
some gravel, scattered cobbles and boulders; brown
-
to grey, iron and anganestaineti, moist, medium
me-sto
10
high plasticity, fine to coarse sand, fine to coarse,
ss2<71
11
subangular gravel,(colluvium).
x18 -Inch diameter boulder encountered from 311 to
12
12.5 feet.
•
13
SS2-5 19
14
Colorado
15
�8
silica sand
6x26
16
Ground
17
water level
18
19
0.010
20
♦ is
'.
machine slot
39-2-7 7 23'.
screen
21
22
23
Ground
24
-
-
water level
25
p0
(10-16-13)
SS2A
26
27
Bentonite
28
chips
29
30
_ -
937.
Extremely, weak (RO)SILTSTONE, bIueSrey, slightly
30.0
55-2-9
15
wea[heretl.
935.
co'6
BOTTOM OF BORING
Project No.: 2131028-101 Boring Log: BH -2
Surface Elevation: 967.7 feet (Approx.) Springfield Utility Board (SUB)
Date of Boring: October 9, 2013 South Hills Reservoir
h Foundation Engineering, Inc. Springfield, Oregon
Page 1 of 1
Depth Soil and Rock Description
and
Feet
Comments
7 Pdamp, 31_5 -inch minus, (fill)(39 inches),____
2Sbff gravelly CLAY some send brown to grey, moist,
medium plasticity, fine to coarse sand, fine to coarse,
3 subsngulargravel (fill).
4 Soft CLAY, some sand, brawn, ironstained, moist,
5 medium plasticity, fine m worse sand, (fill).
6
7 Stiff tory s
vetiff santly CLAY, trace gmyel; broom to
8 light grey, iron and manganeseshimed, moist,
9 medium plasticity, fine to warse sand fine,
subangulargrevel (colluvium).
11
12
13
14
15
16
17
18
19
Very stiff sandy CLAY; light grey, iron -stained, damp
21 low plasticity, fine to coarse sand (residual soil).
22
23
24
25 Exbemely weak (RO) TUFF; light grey grading to
26 blue -grey, ironstained, decomposed to highly
weathered.
27
28
29
31
Project No.: 2131028-101
Surface Elevation: 960.7 feet (Approx.)
Date of Boring: October 9, 2013
Foundation Engineering, Inc.
Mw
Boring Log: BH3
Springfield Utility Board (SUB)
South Hills Reservoir
Springfield, Oregon
Installations/
Water Table
Backfilled
with
bentonite
chips
of 1
Elev.
a. SPT, • Moisture, %
Log
Samples
N -Value
Depth
C Recovery ® ROD., %
960.fia
o 50 15
959..4
0.s
•
5531
13
M.7
4.0
•
S 2
b -
953.]
-
7.0
5533
15
•
553-0
9
5535
9
...._
•
S55fi
a
Boring Log: BH3
Springfield Utility Board (SUB)
South Hills Reservoir
Springfield, Oregon
Installations/
Water Table
Backfilled
with
bentonite
chips
of 1
Foundation Engineering, Inc.
South Hills Reservoir
SUB Reservoirs Seismic Analysis
FEI Proiect 2131028-101
M
BORING: BH -1
BOX 1 OF 2
25.0 FT TO 33.0 FT
Photo 1. BH -1 Box 1
BORING: BH -1
BOX 2 OF 2
33.0 FT .TO 35 FT
Photo 2. BH -1 Box 2
ARk
Professional
Geotechnical
Services
Appendix C
SLIDE 5.0 Output
Foundation Engineering, Inc.
s
U LL q
0-
0 O
N QU) m
o c
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