wa-ef-olymp2022-1-1_GEO_GM1424.pdf

158377846

M E M O R A N D U M Western Federal Lands Highway Division

610 E. Fifth Street Vancouver, WA 98661

DATE: December 19, 2024

TO: David Arena, Project Manager

FROM: Orion George, Engineering Geologist Eric Lim, Senior Geotechnical Engineer

SUBJECT: Geotechnical Memo GM1424 Final Geotechnical Recommendations (Revision 1) Olympic FS ERFO Repairs 2022

WA ERFO FS OLYMP609 2022-1(1)

Olympic National Forest, Clallam County, Washington

INTRODUCTION

This memorandum provides field observations and final geotechnical recommendations for the Olympic National Forest ERFO Repairs 2022 project. The project has 9 sites along the Olympic National Forest (ONF) road system within Clallam County, Washington that were damaged during high precipitation rain-on-snow events from October to December 2021. Seven sites are located on Forest Road 2900, also known as the Sitkum-Solduc Road and two are located on Forest Road 2922, also known as the Hole in the Wall Road. The site locations are shown on Figure 1. The Emergency Relief for Federally Owned Roads (ERFO) program is being used to restore the damaged road sites to their original condition.

SCOPE OF PROJECT

The project scope is for Western Federal Lands Highway Division (WFLHD) to lead and prepare the engineering documents, environmental studies, and construction contract administration to support constructing the repairs at the 9 sites. This memorandum is to be used by the WFLHD cross functional team members to further the project development work agreed to by WFLHD�s Geotechnical Function (GEO).

This memorandum presents findings from an office review of available forest practice applications, published literature, geologic maps, and remotely sensed data sets, such as historical aerial imagery and light detection and ranging (lidar) topographical models. An initial site visit was on September 6 and 7, 2023, performed by Todd Hansen, WFLHD geological engineer, who visited the sites with the WFLHD and ONF ERFO team. On June 4 and 5, 2024, US. Department of Transportation

Federal Highway Administration

Digitally signed by ERIC J.

ERIC J. LIM ~:e: 2024.12.1909:so:32 -08'00'

Orion George and Eric Lim performed a follow-up visit to the FSR 2900 Mile Post (MP) 7.5 to 7.55, FSR 2900 MP 30.3, and FSR 2922 MP 5.1 sites. Subsurface investigations were outside the scope of this ERFO project and were not performed.

SITE CONDITIONS, INTERPRETATIONS, AND FINAL RECOMMENDATIONS

Site conditions were assessed from detailed damage inspection reports (DDIRs) completed by ONF personnel, an office review of available data, and two site visits. The site conditions and desktop review interpretations are provided by individual site and followed by recommendations for design and construction.

Mapped geology is discussed for each of the sites. Geologic mapping referenced for the desktop review is from three different Washington State Department of Natural Resources (WA- DNR) 1:100,000 scale maps Cape Flattery (Schasse, 2003) and Forks (Gerstel and Lingley, 2000). Additionally, some sites are located within the previous WA-DNR Lower Calawah River Watershed Mass Wasting Assessment: Landslide Hazard Inventory Project (Lingley, 2004).

Aerial lidar data referenced for this project was flown in 2017 and 2018 (WGS, 2024). A number of historical aerial photographs are available via USGS�s Earth Explorer ranging from 1939 to 2019; the photograph resolutions range from 1:37,400 to 1:20,000. More recent imagery is publicly available via Google Earth ranging from 1985 to 2024. We only reviewed the more recent Google Earth imagery for this desktop study.

Figure 1. Relief map of the project locations in relation to the Olympic Peninsula and the city of Forks, Washington.

RFO Sites

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We understand handheld lidar scans were developed at some sites during the September 6 and 7, 2023 site visit with WFLHD and ONF ERFO team members. We understand that these lidar scans will be used in the repair designs.

Site 2900-2.8, Sitkum-Solduc Road

Site Conditions:

A 48-inch diameter corrugated metal pipe (CMP) culvert was blocked by debris, causing the stream to flow over the road, eroding the downhill embankment and oversteepening the slope to near vertical. Height of the downslope eroded and oversteepened embankment was measured at 18 feet in the DDIR. The culvert inlet was buried, and the outlet was crushed. A temporary culvert was installed to continue to convey water through the site, but it is our understanding the eroded embankment has not been addressed.

The DDIR describes the bank full width to be approximately 10 feet wide and describes debris and mud blocking the existing CMP culvert. Review of site photographs and the WFLHD Hydraulics Reconnaissance Report (Bevan, 2023) reports the material blocking the culvert was silty sand to cobble sized materials with branches and logs up to 10 feet long and 1 foot diameter.

Geology at the site is mapped as undifferentiated glacial outwash directly above the roadway, with marine sedimentary rocks mapped further upslope. Site photographs from September 2023 show siltstone bedrock likely exposed in the cut side ditch (Photograph 1). Exposed soils below the road appear to be possible debris flow deposits with silty, angular sand to cobble sized material underlying the road subgrade (Photograph 2).

Photograph 1 Site 2900-2.8

Photograph 2 Site 2900-2.8

Review of Lingley�s (2004) landslide hazard inventory mapping at the site denotes numerous shallow undifferentiated landslide features in the drainage above the site and identified this drainage as a high hazard landform for mass wasting. The WA-DNR mapping does not share any feature characterizing information, but available mapping suggests this drainage is susceptible to debris flows. Further, review of the limited historical aerial imagery with Google Earth shows clear cut forest practices on slopes within the drainage were first visible in 2006, 2009, 2016, and 2021. Following a clear cut, a drainage can see an influx of sediment and debris while vegetation recovers in the watershed.

Recommendations:

We recommend replacing the existing CMP culvert and temporary culvert with a drainage structure designed to transmit the anticipated surface water flows as well as debris flows that could be initiated in future high flow events. It is our understanding ONF has requested installation of a 10-foot culvert at this site. Review of the aerial lidar data suggest a structure of that size could be installed below the road, but there is a possibility of encountering the bedrock observed in the ditch at the site. As such, the contractor should be prepared for rock excavation.

The WFLHD Hydraulic Engineering group should be consulted when considering an appropriate structure.

We also recommend a special rock embankment (SRE, FP-24, Section 252) be constructed below the road to support the roadway and reduce the risk of further erosion of the embankment slope. A SRE can be designed for a face angle of up to 1V:1.25H. If even steeper slopes are required, other options can be considered such as a reinforced soil slope (RSS; FP-24, Section 261), which can provide a face angle from 1V:1.5H to 2V:1H. Placing the SRE may require accessing the area below the road for constructing the foundation.

Site 2900-3.1 Sitkum-Solduc Road

Site Conditions:

A 36-inch diameter CMP culvert was blocked by debris causing the drainage to overflow the road. Debris was deposited on the roadway and the embankment was eroded and oversteepened to near vertical. Height of the downslope, eroded, oversteepened embankment slope was measured at 13 feet in the DDIR and extended approximately 50 feet downslope from the edge of pavement. The culvert was damaged beyond repair. Debris was removed from the site to open the road to traffic, and a temporary plastic pipe was installed to permit drainage.

The DDIR describes the culvert blocking debris as �silts, mud, and softball sized cobbles�.

Review of site photographs suggest cobbles and boulders up to approximately 2 feet in dimension were also in the debris.

Mapped geology has undifferentiated glacial outwash directly above the roadway with marine sedimentary rocks mapped further upslope and alluvium deposits at the site. Site photographs

Photograph 3 Site 2900-3.1 suggest soils directly above the roadway are unsorted silty sand, gravel, and cobbles (angular to sub angular), similar to debris fan deposits (Photograph 3). Review of aerial lidar topographic derivatives suggest the roadway is crossing a debris fan near its apex (WGS, 2024).

Review of Lingley�s (2004) landslide hazard inventory mapping at the site denotes numerous shallow undifferentiated landslide features in the drainage above the site and identified this drainage as a high hazard landform for mass wasting. The WA-DNR mapping does not share any feature characterizing information, but available mapping suggests this drainage is susceptible to debris flows. Further, review of the limited historical aerial imagery with Google Earth shows clear cut forest practices on slopes within the drainage were first visible in 2006, 2009, 2016, and 2021. Following a clear cut, a drainage can see an influx of sediment and debris while vegetation recovers in the watershed.

Recommendations:

We recommend replacing the existing CMP culvert and the temporary culvert with a drainage structure designed to transmit the anticipated surface water flows as well as debris flows that could be initiated in future high flow events. It is our understanding ONF has requested installation of a 48-inch diameter culvert at this site. Review of the aerial lidar data suggest a structure of that size could be installed below the road, but there is a possibility of encountering boulders in the excavation within the debris flow fan deposit. The WFLHD Hydraulic Engineering group should be consulted when considering an appropriate structure.

Site 2900-7.5 Sitkum-Solduc Road

This site has two associated DDIRs, 2900-7.5 and 2900-7.55. Due to their proximity these two sites were combined for their considerations and designs.

Site Conditions:

Geology is mapped as undivided marine sedimentary rocks of thick and thinly interbedded sandstone and siltstone with some slate and traces of coal with bedding dipping into the slope (and east-west aligned roadway) to the north-northeast at 45 degrees to 85 degrees. The soil exposed in the headscarp of the failure areas was generally wet, silty sand with gravel, cobbles, and boulders.

2900-7.5: A 36-inch diameter CMP culvert was clogged and destroyed by hundreds of yards of soil, boulders, and large woody debris. The blockage caused overtopping of the roadway and minimal erosion of the embankment slope. Material, about 5 feet deep, was deposited on top of the roadway. ONF personnel cleared debris from the site and installed a temporary plastic pipe for drainage.

Photograph 4 Site 2900-7.5 Photograph 5 Site 2900-7.5

Review of lidar-derived topography shows the drainage above the site is constrained and straight and bedrock outcrops directly above the road were observed in the site photographs.

Additionally, recently constructed logging roads were visible in the October 2013 aerial photographs and the 2016 aerial photographs show clear cutting in the upper watershed, suggesting logging occurred about 2014 (Google Earth, 2024). It is typical for watersheds to have increased precipitation throughfall and surface water infiltration as well as disturbed surface water flow following these types of land uses, which can increase rates of erosion.

The combination of these conditions are at high risk to deliver rapid debris flows in the future (Photographs 4 and 5).

2900-7.55: The site is on the downstream edge of an outer bend of the South Fork Calawah River and the road was undercut by high flows that intermittently eroded the embankment for approximately 320 feet. Bedrock is exposed in a cut above the road with a minimal rockfall catchment ditch, and we understand this site has a history of rockfall (Photographs 6 and 7).

Site photographs from the DDIRs and our site visit show bedrock outcrops below the road and within the river channel. Numerous discontinuities with varying orientations were visible in site photographs. Photographs of the bedrock cut slope also shows vegetation and overlying soils further up the slope and overhanging ledges of fairly fractured rock. The ditch appears mostly filled with vegetation and rock debris assumed to be from the slopes above. These conditions suggest an ongoing rockfall hazard, which should be assessed further if the cut slope will be modified. Review of a lidar derived topography shows the current rock cut slopes from about 60 degrees up to 75 degrees (about 2V:1H: to 5V:1H).

Recommendations:

Photograph 6 Site 2900-7.55 Photograph 7 Site 2900-7.55

In our opinion, this site has a high hazard to debris flows and we recommend constructing a debris passage to enhance the resilience of the crossing to future debris flow type events.

We recommend designing reinforced soil slopes (RSS) at a ~2V:1H face angle to protect the road from further erosion and undermining from the South Fork Calawah River. We modeled the RSS�s using ReSSA+ software by Adama Engineering. The length of the geogrid reinforcement, L, was modeled at approximately 0.8 times the RSS height, H, with a minimum length of 8 feet. The current RSS profile shows a maximum height of approximately 16 feet to restore the roadway, which results in a geogrid reinforcement length of approximately 13 feet.

Drilling is outside the scope of this work so the depth to bedrock and bearing capacity of soils or rock for the foundations will have to be determined during excavation and construction. If strong bedrock is encountered that cannot be excavated with heavy equipment (e.g., a CAT 200-series excavator with a bucket equipped with rock teeth), then the geogrid reinforcement length can potentially be reduced to a 40 percent L/H ratio at the RSS wall base. The excavation should be benched to the 80 percent design length where excavation conditions allow a minimum of the top two layers of geogrid at their full design length. These changes during construction will require approval through the Contracting Officer (CO).

Table 1 summarizes the factor of safety results for the ReSSA+ analyses in the attachments.

For seismic conditions, we assumed a site class �B� and mapped the site with a modified peak ground acceleration, As, of 0.42g. A standard of practice for flexible retaining structures is to use 50 percent of the As, resulting in a horizontal seismic coefficient, kh, of 0.21 g for pseudo-static analysis. The results indicates adequate factors of safety above 1.3 for static conditions and approximately 1.1 or better for seismic conditions. Results of the ReSSA+ analysis are attached.

Table 1. ReSSA+ Results Summary

Analysis Method Static Factor of

Safety Seismic Factor of

Safety

Bishop rotational failure 1.6 1.1

Spencer 2-part wedge sliding failure 1.9 1.3

Spence 3-part wedge failure 1.7 1.2

WFLHD�s Hydraulic Team should analyze the scour potential along this section of the road.

Drainage design for a RSS wall is important for the foundation and backfill. We understand the accelerated timeline of this work makes environmental permitting for in-water work challenging so designing the bottom of the RSS walls to be above ordinary high water is recommended.

Site 2900-11.1 Sitkum-Solduc Road

This site is a culvert replacement, and no geotechnical assessment was performed.

Site 2900-30.3 Sitkum-Solduc Road

Site Conditions:

An 18-inch diameter CMP culvert was blocked by debris causing overflow that ran down the road approximately 40 feet before flowing off the road and eroding the embankment. The culvert appears undamaged at the inlet and outlet, based on the DDIR and our site visit. The upper 18 feet of the embankment below the road eroded to a near vertical slope that transitioned to an approximately 30 degree slope for the lower 200 feet to the bottom of the drainage. The road embankment is oversteepened and at risk of further shoulder failure with limited area to catch new fill embankment material (Photographs 8 and 9).

Photograph 8 Site 2900-30.3 Photograph 9 Site 2900-30.3

Geology throughout this area is mapped as undifferentiated marine sedimentary bedrock. A lack of bedding orientations on the map suggests soil is largely covering the surrounding area.

No landslides are mapped in the area surrounding the site.

Review of historical aerial imagery available on Google Earth shows areas above and near the site were logged previous to imagery collected in 1985.

Recommendations:

We recommend conditioning the ditch at this site to reestablish positive drainage to the culvert.

At the site of the undermined road, 40 feet away from the culvert, we recommend constructing a structure that can build up the embankment below the road and reestablish vegetation.

Revegetation at the site, particularly of alder trees, a fast-growing primary species that typically grows in areas of land disturbance, will increase shallow soil strengths and improve the overall slope stability of the site.

We recommend a Special Rock Embankment (SRE) designed with a face angle of 1:1 with the addition of galvanized steel welded wire mesh reinforcement layers. Based on our experience on previous ERFO projects, a 1:1 SRE reinforced with steel mesh can be successfully constructed. A stable key or bench at the base of the SRE will be critical to its stability, and access will be difficult and likely require multiple temporary benches for equipment access, a spider-type excavator, or a long-reach excavator.

Site 2900-33.9 Sitkum-Solduc Road

Site Conditions:

The DDIR stated that heavy stormwater runoff and debris clogged and destroyed a 36-inch diameter plastic pipe. The runoff overflowed and washed out the entire road prism at a curve in the road. Photograph 10 shows the failure area facing downstream.

Recommendations:

Replace the culvert with a 60-inch equivalent diameter arch or elliptical culvert and rebuild the road prism. We recommend constructing the embankment with unclassified borrow at 1V:1.5H or flatter to overlap around the tight radius turn.

Photograph 10 Site 2900-33.9

Site 2922-3.1 Hole in the Wall Road

Site Conditions:

The DDIR stated that a large section of the road slumped (Photographs 11 and 12).

Recommendations:

We understand the plan from the initial CFT site visit was to fill the sunken roadway with unclassified borrow to restore access at the previous grades. An 8-foot deep underdrain on the uphill side of the road was also recommended in the DDIR, and we understand this will be added to the plan set. WFLHD GEO also recommends installing geosyntethic reinforcement to the backfill, especially overlapping the lateral scarps of the landslide to reduce the abruptness of future downslope movements. Although this form of deep patch is not intended to stop the overall landslide movements, it could be helpful in keeping the roadway passable for longer periods between maintenance actions.

Photograph 11 Site 2922-3.1 Photograph 12 Site 2922-3.1

Site 2922-5.1 Hole in the Wall Road

Site Conditions:

This site is located at over 2,000 feet in elevation, near the top of a ridge. The DDIR reported that heavy rain from the November 2021 storm event saturated the fill slopes below the road and exposed a plastic pipe outlet, likely concentrating surface water and causing a 105-foot-long failure that extended at least 20 feet deep. Snow was also likely on the ground and melted during the storm event, increasing the amount of moisture to saturate soils during runoff. In addition, the concave slopes below the road form a colluvial hollow, making them more susceptible to concentrated, shallow groundwater and failures.

Review of a lidar derived topography map indicates cut slopes above the site are generally from 50 to 55 degrees (approximately 1.25V:1H), and are as steep as 70 degrees. Historical aerial imagery via Google Earth did not reveal any forest practices on the slopes adjacent to the site since at least 1985.

Geology is mapped as undifferentiated marine sedimentary bedrock throughout this area.

Bedding is generally dipping to the northeast and ranging from 49 degrees to 67 degrees. This bedding is adversely dipping to the northeast in the drainage that failed. Two shallow, undifferentiated landslides are mapped in the area surrounding the site from WA-DNR�s landslide layer. The materials observed in the landslide headscarp of the failure area were generally wet, silty sand with gravel, cobbles, and boulders.

Photograph 13 Site 2922-5.1 Photograph 14 Site 2922-5.1

Recommendations:

We recommend reestablishing a new drainage ditch, replacing the culvert for drainage under the road, and constructing an RSS. Surrounding natural slopes with established vegetation are approximately 40 degrees on average.

We modeled the RSS using limit equilibrium methods in Slide2 software by Rocscience. Due to the very steep topography, the length of the geogrid reinforcement, L, was lengthened to 1.2 times the RSS height with a minimum length of 8 feet. The current RSS profile shows a maximum height of approximately 12 feet to restore the roadway, which results in a geogrid reinforcement length of approximately 13 feet. The model indicates a factor of safety of approximately 1.23 using the Spencer method for static conditions, with a conservative factor of safety of 1.11 using the Janbu simplified method. For seismic conditions, we assumed a site class �D� and mapped the site with modified peak ground acceleration, As, is 0.44g. A standard of practice for flexible retaining structures is to use 50 percent of the As, resulting in a horizontal seismic coefficient, kh, of 0.22 g for pseudo-static analysis. The resulting pseudo-static analysis indicates a factor of safety below 1.0, indicating significant movement would likely develop during a seismic event. Due to the slope on the cut side of the roadway, additional lengthening of the geogrids would not be constructable without shoring. Therefore, the Forest should be aware that the seismic risk is high for this retaining structure. In all likelihood, other parts of the roadway would also be damaged during a design seismic event, and designing this repair for seismic resiliency may be beyond the scope of the ERFO program. Graphic results of the Slide2 models are contained in the attachments to this memorandum. It is possible that bedrock could be encountered in the excavation, thus improving the factor of safety. However, without subsurface explorations to confirm this condition, we conservatively ignored the presence of bedrock in the slope stability model.

Obtaining additional soils data would better define proposed cut slope angles and may reduce the overall project footprint. Reestablishing vegetation will maintain stability of the soil cut slope and should be prioritized as part of the improvements.

MATERIAL SOURCES AND WASTE SITES

We understand that there will be no Government-provided material sources for borrow soils and rock, such as riprap and special rock embankment. These materials will need to be sourced commercially by the contractor.

Designated waste sites will not be Government-provided either. All unsuitable and excess excavated materials that cannot be reused for reconstruction at the project sites will need to be hauled off-site by the contractor, and permitted to meet State and local regulations as necessary.

CLOSURE

For questions regarding this memorandum, please contact Eric Lim at 360-619-7826 or eric.lim@dot.gov.

Attachments: ReSSA+ Static Analysis for Site 2900-7.5 ReSSA+ Seismic Analysis for Site 2900-7.5 Slide2 Static Analysis for Site 2922-5.1

Slide2 Seismic Analysis for Site 2922-5.1

CC: Ace Vergara, Highway Design Douglas A. Anderson, GEO Team Functional Manager

Mark Swank, Engineering Geology Team Lead Vernon Bevan, Hydraulics Engineer Geotechnical File

REFERENCES

Bevan, V., 2023, OLYMP609 2022-1(1) Hydraulics reconnaissance report, dated November 9, 2023, written for Western Federal Lands Highway Division.

Lingley, W. S., Jr., 2004, Mass wasting assessment, Lower Calawah Valley Watershed, Clallam County, Washington: Landslide Hazard Inventory Project, Washington Department of Natural Resources, Olympia, Washington.

Gerstel, W.J. and W.S. Lingley, compilers, 2000, Geologic map of the Forks quadrangle, Washington: Washington State Department of Natural Resources, scale 1:100,000, 2 sheets, 42 p.

Google Earth Pro [v. 7.3.3.7786 (32-bit)], 2024, historical imagery for western Clallam County, Washington: [1985 to 2024], accessed June 2024.

Lingley, W. S., Jr., 2004, Mass wasting assessment, Lower Calawah Valley Watershed, Clallam County, Washington: Landslide Hazard Inventory Project, Washington Department of Natural Resources, Olympia, Washington.

Schasse, H.W., compiler, 2003, Geologic map of the Washington portion of the Cape Flattery 1:100,000 quadrangle, Washington State Department of Natural Resources, 1 sheet.

Washington Department of Natural Resources (WA-DNR), 2024, Washington Geologic Information Portal, available at: https://geologyportal.dnr.wa.gov/, accessed June 2024.

Washington Geological Survey (WGS), 2024, Olympics North Opsw 2018 project [QL1 lidar data]: originally contracted by Washington Dept. of Natural Resources. [accessed March 30, 2024, at http://lidarportal.dnr.wa.gov]

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

ReSSA+ Stability Analysis of Geosynthetic Reinforced Soil Structures Olympic FS ERFO Repairs 2022 Present Date/Time: Wed Jul 24 14:30:10 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

Olympic FS ERFO Repairs 2022 Report created by ReSSA+: Copyright (c) 2001-2019, ADAMA Engineering, Inc.

PROJECT IDENTIFICATION

Title: Olympic FS ERFO Repairs 2022 Project Number: WA_ERFO_FS_Olymp609_2022-1(1) - Client: USFS Designer: EJL Station Number: 2900 MP7.55 STA 1+30

Description:

14-ft tall RSS supporting roadway above OHW

Company's information:

Name: FHWA Western Federal Lands Highway Division Street: 610 East Fifth Street

Vancouver, WA 98661 Telephone #: 360-619-7826 Fax #:

E-Mail: eric.lim@dot.gov

Original file path and name: C:\Users\e ..... design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp Original date and time of creating this file: Wed Jul 24 11:59:43 2024

PROGRAM MODE: Analysis of a General Slope using GEOSYNTHETIC as reinforcing material.

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048

Static Analysis

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Origfumall dare and time of creatmg tlbuis file:

JP'ROGJRAM MODE:

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:10 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

INPUT DATA (EXCLUDING REINFORCEMENT LAYOUT)

SOIL DATA

=========== Soil Layer #: =========== Unit weight, [lb/ft ³]

Internal angle of friction, [deg.] Cohesion, c

[lb/ft ²]

...........................................................................1 Reinforced Soil 135.0 38.0 0.0

...........................................................................2 Retained Soil 125.0 32.0 0.0

...........................................................................3 Foundation Soil 135.0 40.0 0.0

...........................................................................4 160.0 50.0 1000.0

REINFORCEMENT

R e i n f o r c e m e n t

Type # Geosynthetic Designated Name

Ultimate Strength, Tult

Reduction Factor for Installation Damage, RFid

Reduction Factor for Durability, RFd

Reduction Factor for Creep, RFc

Additional Reduction Factor, RFa

Coverage Ratio, Rc

[lb/ft]

1 Type 3 Geogrid 2000.00 1.00 1.00 1.00 1.00 1.00

I n t e r a c t i o n P a r a m e t e r s Type # Geosynthetic

Designated Name

== Direct Sliding == ==== Pullout ==== Cds-phi Cds-c Ci Alpha

1 Type 3 Geogrid 0.80 0.00 0.67 0.80

Relative Orientation of Reinforcement Force, ROR = 0.00. Assigned Factor of Safety to resist pullout, Fs-po = 1.50 Design method for Global Stability: Comprehensive Bishop.

WATER

Unit weight of water = 62.45 [lb/ft ³] Water pressure is defined by phreatic surface in Effective Stress Analysis.

SEISMICITY

Not Applicable

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048 c=J c=J c=J c=J llNJP>UT DA'fA (]EXCLUDING RlEllNJFORCEMIEN'f LAYOUT)

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WA'fER

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ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:10 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

DRAWING OF SPECIFIED GEOMETRY - GENERAL

-- Problem geometry is defined along sections selected by user at x,y coordinates.

-- X1,Y1 represents the coordinates of soil surface. X2,Y2 represent the coordinates of the end of soil layer 1 and start of soil layer 2, and so on.

-- Xw,Yw represents the coordinates of phreatic surface.

GEOMETRY

Soil profile contains 4 layers (see details in next page)

WATER GEOMETRY

Phreatic line was specified.

UNIFORM SURCHARGE

Load Q1 = 250.00 [lb/ft²] inclined from verical at 0.00 degrees, starts at X1s = 8.00 and ends at X1e = 32.00 [ft].

.......................................................................Surcharge load, Q2 None .......................................................................Surcharge load, Q3 None

STRIP LOAD

.......................................................................None

Toe point

2 3

6 7 8 9 10 1112 13

SCALE:

0 2 4 6[ft]

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048

DAA Wl!NG Of SlPEClDFlDED GEO:MDE'fR.Y - GENJEJRAJL

GEO:MDE'fR.Y

WATER GEO:MDE'fR.Y

UNJDFOJRM SUR.CHAR.GE

SmJDP> LOAD

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:10 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

TABULATED DETAILS OF GENERAL SPECIFIED GEOMETRY

Soil profile contains 4 layers. Coordinates in [ft.] Water was described by phreatic line.

# Xi Yi Top of Layer 1 1 -20.00 -10.00

2 -2.00 2.00 3 -0.03 2.00 4 0.00 0.00 5 7.80 15.50 6 10.00 15.50

Top of Layer 2 7 -20.00 -10.00 8 -2.00 2.00 9 -0.03 2.00 10 0.00 0.00 11 12.00 0.00 12 20.00 14.00 13 25.00 15.50 14 30.00 15.50

Top of Layer 3 15 -20.00 -10.00 16 -2.00 2.00 17 -0.03 2.00 18 0.00 0.00 19 12.00 0.00 20 17.20 9.00 21 24.00 14.00

Top of Layer 4 22 -20.00 -10.00 23 -2.00 -5.00 24 12.00 0.00 25 30.00 6.00

Top of Phreatic Line 27 0.00 0.00 28 0.03 0.00 29 12.00 0.00 30 30.00 7.00

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048

1'AJBUJLA1'ED DE1'All,§ OlF GENEJRAJL Sl?ECJDFIBD GEOMDE1'R.Y

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:10 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

TABULATED DETAILS OF SPECIFIED GEOMETRY

Soil profile contains 4 layers. Coordinates in [ft.] Water was described by phreatic line. Y values are tabulated in the right most column.

# X Y1 Y2 Y3 Y4 Yw (phreatic)

1 -20.00 -10.00 -10.00 -10.00 -10.00 0.00 2 -2.00 2.00 2.00 2.00 -5.00 0.00 3 -0.03 2.00 2.00 2.00 -4.30 0.00 4 0.00 0.00 0.00 0.00 -4.29 0.00 5 0.03 0.06 0.00 0.00 -4.28 0.00 6 7.80 15.50 0.00 0.00 -1.50 0.00 7 10.00 15.50 0.00 0.00 -0.71 0.00 8 12.00 15.50 0.00 0.00 0.00 0.00 9 17.20 15.50 9.10 9.00 1.73 2.02 10 20.00 15.50 14.00 11.06 2.67 3.11 11 24.00 15.50 15.20 14.00 4.00 4.67 12 25.00 15.50 15.50 14.00 4.33 5.06 13 30.00 15.50 15.50 14.00 6.00 7.00

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048

1'ABUJLATED DE1'AJDLS OlF SJPECWIBD GEO:ME1'RY

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:10 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

DISTRIBUTION OF AVAILABLE STRENGTH ALONG EACH REINFORCEMENT LAYER

A = Front-end of reinforcement (at face of slope) B = Rear-end of reinforcement AB = L1 + L2 + L3 = Embedded length of reinforcement

Tavailable = Long-term strength of reinforcement Tfe = Available front-end strength (e.g., connection to facing) Tr-o = Pullout resistance at rear-end

L1 = Front-end 'pullout' length L2 = Rear-end pullout length Tavailable prevails along L3

Factor of safety on resistance to pullout on either end of reinforcement, Fs-po = 1.50

Reinforcement Layer #

Designated Name

Height Relative to Toe [ft]

L [ft]

L1 [ft]

L2 [ft]

L3 [ft]

Tfe [lb/ft]

Tr-o [lb/ft]

Tavailable [lb/ft]

1 Type 3 Geogrid -1.50 12.00 0.00 1.77 10.23 2000.00 0.00 2000.00 2 Type 3 Geogrid 0.00 12.00 0.00 1.97 10.03 2000.00 0.00 2000.00 3 Type 3 Geogrid 1.50 12.00 0.00 2.23 9.77 2000.00 0.00 2000.00 4 Type 3 Geogrid 3.00 12.00 0.00 2.56 9.44 2000.00 0.00 2000.00 5 Type 3 Geogrid 4.50 12.00 0.00 2.95 9.05 2000.00 0.00 2000.00 6 Type 3 Geogrid 6.00 12.00 0.00 3.54 8.46 2000.00 0.00 2000.00 7 Type 3 Geogrid 7.50 12.00 0.00 4.43 7.57 2000.00 0.00 2000.00 8 Type 3 Geogrid 9.00 12.00 0.00 5.91 6.09 2000.00 0.00 2000.00 9 Type 3 Geogrid 10.50 12.00 0.00 8.86 3.14 2000.00 0.00 2000.00

10 Type 3 Geogrid 12.00 12.00 0.00 12.00 0.00 1312.30 0.00 1312.30 (*)

(*) This Tavailable is dictated by the pullout resistance capacity, which is smaller than the long-term strength of the reinforcement that is related to its specified ultimate strength.

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048

D][§'ffiIBUTKON OlF AV AJDLABLE STIIBNGffi ALONG EACH llIBl!NlFOR.CE:MDENT LA YER

T

I available ----·

Tfe Tr-o

A B i L1 t L3 t L2 t-

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:11 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

RESULTS OF ROTATIONAL STABILITY ANALYSIS

Results in the tables below represent critical circles identified between specified points on entry and exit. (Theta-exit set to 50.00 deg.)

The most critical circle is obtained from a search considering all the combinations of input entry and exit points.

Critical circles for each entry point (considering all specified exit points) Entry Point #

E n t r y P o i n t ( X , Y )

[ft]

E x i t P o i n t ( X , Y )

[ft]

C r i t i c a l C i r c l e ( Xc , Yc , R )

[ft] Fs STATUS

1 7.97 15.50 -26.09 -9.97 -18.66 15.60 26.63 23.38 2 9.08 15.51 -21.21 -9.93 -16.76 15.52 25.84 12.33 3 10.18 15.50 -21.21 -9.92 -15.84 15.55 26.02 8.58 4 11.29 15.51 -21.21 -9.90 -14.91 15.53 26.20 6.99 5 12.39 15.50 -13.19 -5.31 -8.95 15.60 21.34 4.38 6 13.50 15.50 -13.39 -5.26 -8.45 16.13 21.96 3.71 7 14.60 15.50 -13.29 -5.29 -8.58 17.49 23.26 3.46 8 15.70 15.50 -10.78 -3.50 -4.51 15.72 20.21 2.73 9 16.81 15.50 -10.73 -3.52 -4.53 16.94 21.38 2.35

10 17.91 15.50 -7.89 -1.85 -1.03 15.81 18.95 1.92 11 19.02 15.50 -10.59 -3.57 -4.61 19.67 24.00 1.76 12 20.12 15.50 -10.50 -3.59 -4.69 21.19 25.46 1.68 13 21.23 15.50 -13.02 -5.34 -9.56 27.53 33.05 1.65 14 22.33 15.50 -13.24 -5.32 -9.94 29.83 35.31 1.62

. .15 23.43 15.50 -13.28 -5.32 -9.81 31.34 36.82 1.60 OK

16 24.54 15.50 -15.81 -7.08 -16.46 41.42 48.51 1.60 17 25.64 15.50 -13.20 -5.33 -10.81 36.83 42.23 1.60 18 26.75 15.50 -16.07 -7.09 -17.52 47.53 54.64 1.60 19 27.85 15.50 -13.36 -5.33 -11.37 41.91 47.28 1.62 20 28.96 15.50 -15.84 -7.09 -18.84 54.59 61.75 1.62 21 30.06 15.50 -15.74 -7.08 -20.30 59.89 67.13 1.66 22 31.17 15.50 -16.14 -7.11 -20.50 62.80 70.05 1.66 23 32.27 15.50 -16.05 -7.11 -22.28 69.13 76.50 1.70 24 33.37 15.50 -15.93 -7.10 -22.57 72.46 79.84 1.71 25 34.48 15.50 -15.84 -7.10 -24.78 80.12 87.68 1.77 26 35.58 15.50 -15.72 -7.09 -25.18 83.96 91.54 1.79 27 36.69 15.50 -18.67 -8.89 -39.94 114.41 125.12 1.81 28 37.79 15.50 -18.54 -8.86 -40.98 120.31 131.11 1.82 29 38.90 15.50 -18.44 -8.85 -46.56 137.03 148.56 1.89 30 40.00 15.50 -18.31 -8.83 -47.98 144.34 156.01 1.91

Note: In the 'Status' column, OK means the critical circle was identified within the specified search domain. 'On extreme X-entry' means that the critical result is on the edge of the search domain; a lower Fs may result if the search domain is expanded.

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048

RlE§UlL1'§ OlF R.01'A1'KONAJL §1'ABJDL][1'Y ANAJLY§][§

Critlcaill cfurclies for eaclbt emttry pomt (comidlerimtg aillli specified[ exit ]Pomts)

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:11 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

RESULTS OF ROTATIONAL STABILITY ANALYSIS

Results in the tables below represent critical circles identified between specified points on entry and exit. (Theta-exit set to 50.00 deg.)

The most critical circle is obtained from a search considering all the combinations of input entry and exit points.

Critical circles for each exit point (considering all specified entry points).

Exit Point #

E x i t P o i n t ( X , Y )

[ft]

E n t r y P o i n t ( X , Y )

[ft]

C r i t i c a l C i r c l e ( Xc , Yc , R )

[ft] Fs STATUS

1 -26.37 -9.98 26.75 15.50 -22.82 50.72 60.81 3.34 2 -23.83 -9.98 26.75 15.50 -21.38 48.08 58.11 3.23 3 -19.83 -9.79 30.06 15.50 -44.23 100.22 112.68 1.84 4 -18.61 -8.86 27.85 15.50 -28.90 67.25 76.80 1.68 5 -15.81 -7.08 24.54 15.50 -16.46 41.42 48.51 1.60

. .6 -13.28 -5.32 23.43 15.50 -9.81 31.34 36.82 1.60 OK

7 -10.56 -3.59 23.43 15.50 -5.11 26.52 30.59 1.62 8 -8.04 -1.81 22.33 15.50 -0.58 20.40 23.43 1.71 9 -5.47 -0.03 21.23 15.50 2.84 16.39 18.41 1.94

10 -2.94 1.81 25.64 15.50 7.84 15.99 17.81 4.50 11 0.64 1.72 22.33 15.50 6.44 16.55 15.92 2.33

Note: In the 'Status' column, OK means the critical circle was identified within the specified search domain. 'On extreme X-exit' means that the critical result is on the edge of the search domain; a lower Fs may result if the search domain is expanded.

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048

Critlcaill cfurclies for eaclbt eIDlt pomt (collllSi.dlermg aillli speci.fiedl ennmy ]Pomts).

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:11 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

RESULTS OF TRANSLATIONAL ANALYSIS

Results in the table below represent critical two-part wedges identified between specified starting (X1) and ending (X2) search points. Wedges along all reinforcement layers and at elevation zero are reported. The critical two-part wedge, one for each predetermined elevation, is defined by Xa, Xb and Xc where Xa is the front end of the passive wedge (slope face), Xb is where the passive wedge ends and the active one starts, and Xc is the X-ordinate at which the active wedge starts.

Critical two-part wedge along each interface:

Interface Height Relative to Toe [ft]

( Xa, Ya ) [ft]

( Xb, Yb ) [ft]

( Xc, Yc ) [ft]

Fs STATUS

At toe elevation 0.00 -0.03 2.00 5.32 2.00 26.11 15.50 1.98 OK

. .Reinf. Layer #1 -1.50 0.25 0.50 5.54 0.50 25.45 15.50 1.95 OK Reinf. Layer #2 0.00 1.01 2.00 6.34 2.00 26.35 15.50 2.06 OK Reinf. Layer #3 1.50 1.76 3.50 7.04 3.50 26.24 15.50 2.20 OK Reinf. Layer #4 3.00 2.52 5.00 7.84 5.00 25.31 15.50 2.39 OK Reinf. Layer #5 4.50 3.27 6.50 8.54 6.50 24.13 15.50 2.65 OK Reinf. Layer #6 6.00 4.03 8.00 7.02 8.00 17.34 15.50 2.98 OK Reinf. Layer #7 7.50 4.78 9.50 7.72 9.50 15.68 15.50 3.23 OK Reinf. Layer #8 9.00 5.54 11.00 8.52 11.00 14.71 15.50 3.67 OK Reinf. Layer #9 10.50 6.29 12.50 9.22 12.50 13.35 15.50 4.35 OK Reinf. Layer #10 12.00 7.05 14.00 7.70 14.00 9.43 15.50 3.83 Minimum on Edge

Note: In the 'Status' column, OK means the critical two part-wedge was identified within the specified search domain. 'Minimum on Edge' means the critical result corresponds to a minimum on the edge of the search domain; i.e., either on X1 or X2 or the internally preset limits on Xc.

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048

RlE§UlL 1'§ OlF 1'JRANSLA1'KONAJL ANAJL YSKS

Criticaill two-pm wedlge aillollllg eaclbt mtemce:

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:11 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

RESULTS OF 3-PART WEDGE ANALYSIS

Results in the table below represent the critical slip surface composed of a three-part wedge and identified by the specified points (X-left, Y-left) and (X-right, Y-right) and angles Zeta(L) and Zeta(R). ReSSA finds the (X,Y) coordinates, as well as the angles Zeta, based on user-specified search domain.

The trace of the critical three-part wedge is fully defined by four points: (X1, Y1), (X-left, Y-left), (X-right, Y-right), (X2, Y2).

Critical 3-part wedge (Automatic search):

(X2, Y2) [ft]

Zeta(L) [degrees]

( X-left, Y-left ) [ft]

( X-right, Y-right ) [ft]

Zeta(R) [degrees]

( X1, Y1 ) [ft]

Fs

(-9.46, -2.97) 13.00 (-5.00, -4.00) (8.00, -1.33) 43.00 (26.05, 15.50) 1.714

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048

Toe

(X2,Y2)

RlE§UlL1'§ OlF 3-lP'ARl' WEDGE ANAJLY§][§

(Xl,Yl)

Cri1tfoaill 3-paurt wedge (A1ut1tom.E1tfo seaurcb.):

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Present Date/Time: Wed Jul 24 14:30:11 2024 C:\.....ojects\WA\WA ERFO FS OLYMP609 2022-1(1)\design\ReSSA for MP7.55STA0130 trunc RSS seis.MSEp

CRITICAL RESULTS OF ROTATIONAL AND TRANSLATIONAL STABILITY ANALYSES

Rotational (Circular Arc; Bishop) Stability Analysis

Minimum Factor of Safety = 1.60 Critical Circle: Xc = -9.81[ft], Yc = 31.34[ft], R = 36.82[ft]. (Number of slices used = 59 )

Translational (2-Part Wedge; Spencer), Direct Sliding, Stability Analysis Minimum Factor of Safety = 1.95 Critical Two-Part Wedge: (Xa = 0.25, Ya = 0.50) [ft]

(Xb = 5.54, Yb = 0.50) [ft] (Xc = 25.45, Yc = 15.50) [ft] (Number of slices used = 30 ) Interslice resultant force inclination = 34.51 [degrees]

Three-Part Wedge Stability Analysis Minimum Factor of Safety = 1.71 Critical Three-Part Wedge: (X2 = -9.46, Y2 = -2.97) [ft]

(X-left = -5.00, Y-left = -4.00) [ft] (X-right = 8.00, Y-right = -1.33) [ft] (X1 = 26.05, Y1 = 15.50) [ft] (Number of slices used = 45 ) Interslice resultant force inclination = 28.52 [degrees]

REINFORCEMENT LAYOUT: DRAWING

SCALE:

0 2 4 6[ft]

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+

Olympic FS ERFO Repairs 2022 Copyright © 2001-2019 ADAMA Engineering, Inc. www.GeoPrograms.com License number ReSSA-401048 cruncAJL RESULT§ OlF ROTATKONAJL AND TRAN§LATKONAJL §TABJDUTY ANAJL Y§E§ Rotatiomill (Cnrcullai.r Are; JBlishop) §talbilliity Amlllysis

TransRatiomill (2-f>art Wedlge; §peimcer), Direct §lidlmg. §talbillity Amlllysis

Three-f>art Wedlge §talbillity Amlllysis

RJEl!Nf'ORCEMIENTLAYOUT:DRAwmG

§CAJLE:

ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+ ReSSA+…