GM_27-17_PH-2_Geotechnical_Recommendations.pdf

Memorandum

Western Federal Lands Highway Division 610 E. Fifth Street

Vancouver, WA 98661-3801

Subject: GEOTECHNICAL INFORMATION Date: November 17, 2017 Geotechnical & Construction Recommendations Okanogan-Wenatchee NF Okanogan-Wenatchee 2016 Repairs Phase 2

From: Robert Kraig, Geotechnical Engineer Reply to: HFL-17, Geotechnical Services GM 27-17

To: Susan Ellis, Project Manager Okanogan-Wenatchee 2016 Repairs Phase-2

WA FS ERFO 2016(1)-23(1)

INTRODUCTION

The Okanogan-Wenatchee National Forest (the Forest) encompasses over 4 million acres along the east slopes of the Cascade Range in Washington as shown in Figure 1. The overall project is spread between Okanogan, Chelan, Kittitas and Yakima Counties, Washington, consisting of approximately sixteen repair sites along National Forest Roads (NFR). The roads provide recreational and administrative access to the National Forest (NF). Not all the repair sites required geotechnical evaluation.

Figure 1: Location of Okanogan-Wenatchee National Forest (shown in yellow outline)

On August 14, 2017, the WFL Geotechnical Team was asked to assess damage, make observations, obtain general information, and make repair recommendations for three sites that experienced damage resulting from a widespread storm event that occurred in winter 2016/2017. The three sites; NFR 1000 MP 11.7 and NFR 1040 MP 0.1 (located in Yakima County), and NFR 3507 MP 8.0 (located in Kittitas County), required geotechnical assessment and repair recommendations as discussed in this memorandum. This memorandum contains background and design information and construction recommendations for the proposed repairs at the FSR 1000 MP 11.7, FSR 1040 MP 0.1 and FSR 3507 MP 8.0 sites. The project vicinity is shown in Figure 2.

Figure 2: Vicinity of repair site locations

GEOLOGY

The sites are located roughly in the middle section of the Cascade Mountain Range with both lying slightly eastward of the crest in the direction of the foothills and valleys between the mountains and the Columbia River Plain.

NFR 1000 MP 11.7 & NFR 1040 MP 0.1

A database search for available geologic mapping resulted in obtaining the excerpt shown in Figure 3. Reference to the figure shows that the NFR 1040 0.1 site is interpreted to lie at the boundary of KJr and Qal mapped units. The KJr mapped unit is described as a clastic subunit of the Russell Ranch Unit (Marine sedimentary rocks of the Cretaceous-Jurassic) as follows:

Clastic subunit of the Russell Ranch Unit (Cretaceous-Jurassic)—Formally referred to as the Russel Ranch Formation (see Miller, 1985) for details concerning nomenclature change: a voluminous, chaotically deformed supracrustal sequence of interbedded lithofeldspathic sandstone and mudstone, with lesser conglomerate and greenstone, minor chert, and very rare green tuff, showing turbidite characteristics of the flysch facies (Clayton, 1983: Miller, 1985); unit is tectonically deformed and broken: limestone cobbles occurring locally and prominent in an olistrohomal boulder breccia have yielded fusulinids of probable Permian age (Ellingson, 1972); contains radio larian fauna referable to the Tithonian and Valaginian or Hauterivian Stages (Charles Blome, USGS, written communication, 1986); consists of part of the Russell Ranch Formation (Simmons, 1950;

Ellingson, 1972; Swanson, 1978; Schreiber, 1981; Clayton, 1983; Miller, 1985).

Figure 3: Excerpt from the Geologic Map of the Mount Rainier Quadrangle, Washington (1987, Schasse, H.W., Washington Division of Geology and Earth Resources)

The Qal mapped unit is shown as Alluvium and described as follows:

Silt, sand, and gravel deposited in streambeds and fans; surface relatively undissected;

includes some low-level terraces and some lacustrine deposits; may include some glacial deposits and some volcanic mudflow deposits.

NFR 3507 MP 8.0

Referencing an excerpt from the geologic mapping shown in Figure 4, the NFR 3507 8.0 site lies within a Qls mapped unit described as:

Landslide deposits, undifferentiated—Poorly sorted deposits ranging from muddy boulder gravel to boulder mud; clasts are angular and of only one or two local rock types; most slides have hummocky surfaces, bulbous toes, and moats at the head and margins

1040 0.1

N 1000 11.7

Qal smaller slides generally head at theater-shaped scars; some large slides merge headward with block slides.

Figure 4: Excerpt from the Geologic Map of the Wenatchee1:100,000 Quadrangle, Central

Washington. (Geologic Map of the Mount Rainier Quadrangle, Washington (1982, R. W. Tabor, R. B.

Waitt, V. A. Frizzell, D. A Swanson, F. R. Byerly, and R. D. Bentley) Department of the interior, United

States Geological Survey

CLIMATE

The data listed in Tables 1-A through 1-G contains information obtained through the National Climate Data Center (NCDC). Recorded observations are provided in the tables for four NCDC weather reporting stations nearby NFR 1000 MP 11.7 and NFR 1040 MP

0.1 (Figure 5) and three NCDC reporting stations nearby the NFR 3507 MP 8.0 site (Figure 6).

The four NCDC stations nearby NFR 1000 11.7 and NFR 1040 MP 0.1 are:

• Packwood (20 miles to the west-northwest);

• Mount Adams Ranger Station (42 miles to the south-southwest);

• Yakima 5 WSW (30 miles to the east); and

• Glenwood Number 2 (39 miles to the south)

Note that all distances given above were measured from the 1040 0.1 repair site and that the 1000 11.7 site is located about 4 miles to the south-southwest of the 1040 0.1 site.

The three NCDC reporting stations nearby NFR 3507 MP 8.0 are:

3507 8.0

Qls

• Leavenworth 3 S (20 miles to the north);

• Cle Elum (15 miles to the southwest); and

• Wenatchee Experimental Station (17 miles to the northeast)

Note that in all cases the distances given are approximate. Elevations as reported by the NCDC are shown in the tables. The NFR 1000 MP 11.7 site is at about 4000 elevation, the NFR 1040 MP 0.1 site is at approximately 3700 feet, and the NFR 3507 MP 8.0 site is at roughly 4500 feet.

Note that the data appearing in the tables is for the most recent climate normal and is not a summary of all possible observations at those stations. Precipitation taking the form of snow is included in the tables. (Snow accumulations, discussed later, are not shown.)

Table 1-A: Temperature and Precipitation Data* 1981 – 2010 (Packwood—elev. 1060 ft)

Month Temperature Precipitation Mean (inches) Daily Max. Daily Min. Mean

January 43.7 31.9 37.8 8.96 February 48.8 31.7 40.3 6.05 March 53.5 35.0 44.2 5.43 April 59.0 38.1 48.6 3.67 May 65.9 44.1 55.0 2.88 June 71.0 49.5 60.3 2.09 July 78.0 53.6 35.8 0.91 August 78.9 52.9 65.9 0.87 September 73.6 46.8 60.2 2.06 October 61.2 40.3 50.7 5.02 November 48.3 35.5 41.9 9.95 December 41.7 30.8 36.3 8.11

*Data obtained from the National Climatic Data Center (NCDC), Station: Packwood, WA US USC00456262.

Table 1-B: Temperature and Precipitation Data* 1981 – 2010 (Mount Adams Ranger Station—elev. 1950 ft.)

Month Temperature Precipitation Mean (inches) Daily Max. Daily Min. Mean

January 38.2 25.1 31.7 7.36 February 42.6 25.7 34.1 5.14 March 50.1 29.3 39.7 5.50 April 58.6 32.6 45.6 2.44 May 67.3 38.8 53.0 1.65 June 74.0 44.4 59.2 1.27 July 83.4 48.9 66.1 0.45 August 83.4 47.7 65.5 0.65 September 74.9 41.0 57.9 1.11 October 60.4 33.9 47.2 3.91 November 44.6 29.5 37.1 7.78 December 35.5 24.0 29.7 8.63

*Data obtained from the National Climatic Data Center (NCDC), Station: Mount Adams Ranger Station, WA US USC00455659

Table 1-C: Temperature and Precipitation Data*

1981 – 2010 (Yakima 5 WSW—elev. 1160 ft.)

Month Temperature Precipitation

Mean (inches) Daily Max. Daily Min. Mean January 38.9 23.3 31.1 1.11 February 48.2 26.3 37.3 0.73 March 57.9 31.1 44.5 0.69 April 65.0 37.7 51.4 0.57 May 74.2 43.8 59.0 0.69 June 81.4 51.0 66.2 0.75 July 88.5 55.3 71.9 0.20 August 87.5 54.0 70.8 0.25 September 79.7 46.7 63.2 0.47 October 64.5 37.0 50.8 0.55 November 49.4 29.0 39.2 1.13 December 36.8 23.6 30.2 1.53

*Data obtained from the National Climatic Data Center (NCDC), Station: Yakima 5 WSW, WA US USC00459455.

Table 1-D: Temperature and Precipitation Data* 1981 – 2010 (Glenwood Number 2—1902 ft.)

Month Temperature Precipitation Mean (inches) Daily Max. Daily Min. Mean

January 39.6 23.7 31.6 5.58 February 44.5 24.4 34.4 3.96 March 51.9 27.9 39.9 3.04 April 58.3 30.0 44.2 1.35 May 66.7 35.2 50.9 1.19 June 73.1 40.3 56.7 0.78 July 81.4 43.2 62.3 0.25 August 81.8 42.2 62.0 0.27 September 74.8 34.9 54.8 0.88 October 62.4 29.3 45.8 2.03 November 47.5 27.0 37.2 5.31 December 37.6 21.9 29.8 6.73

*Data obtained from the National Climatic Data Center (NCDC), Station: Glenwood Number 2, WA US US45.8C00453184

Table 1-E: Temperature and Precipitation Data* 1981 – 2010 (Leavenworth 3 S—elev. 1128 ft.)

Month Temperature Precipitation Mean (inches) Daily Max. Daily Min. Mean

January 34.6 20.3 27.4 4.50 February 42.7 22.1 32.4 2.63 March 53.1 28.2 40.7 2.09 April 62.3 33.9 48.1 1.11 May 71.1 40.9 56.0 1.07 June 78.3 47.5 62.9 1.07 July 87.2 52.2 69.7 0.39 August 87.5 51.4 69.4 0.46 September 78.7 42.6 60.7 0.65 October 63.3 33.6 48.4 2.07 November 44.2 27.6 35.9 4.50 December 32.9 19.6 26.2 4.49

*Data obtained from the National Climatic Data Center (NCDC), Leavenworth 3 S. WA US USC00454572

Table 1-F: Temperature and Precipitation Data* 1981 – 2010 (Cle Elum—elev. 1900 ft.)

Month Temperature Precipitation Mean (inches) Daily Max. Daily Min. Mean

January 35.6 23.9 29.7 2.98 February 41.0 24.5 32.7 2.58 March 49.7 29.5 39.6 1.98 April 57.0 33.8 45.4 1.07 May 64.8 40.6 52.7 1.15 June 71.4 47.3 59.3 0.89 July 79.9 53.0 66.5 0.59 August 80.4 51.7 66.0 0.50 September 72.5 42.8 57.6 0.81 October 58.4 34.4 46.4 1.91 November 42.7 29.0 35.9 4.31 December 33.2 21.9 27.6 3.50

*Data obtained from the National Climatic Data Center (NCDC), Station: Cle Elum, WA US USC00451504

Table 1-G: Temperature and Precipitation Data* 1981 – 2010 (Wenatchee Experimental Station—elev. 800 ft.)

Month Temperature Precipitation Mean (inches) Daily Max. Daily Min. Mean

January 36.9 24.4 30.6 1.53 February 44.3 26.4 35.3 1.11 March 55.5 32.0 43.8 0.70 April 64.1 37.8 50.9 0.64 May 72.9 45.4 59.2 0.55 June 79.8 52.8 66.3 0.63 July 88.4 57.1 72.7 0.29 August 87.7 55.9 71.8 0.23 September 78.9 46.3 62.6 0.34 October 63.0 35.9 49.5 0.57 November 46.1 29.3 37.7 1.39 December 34.4 22.6 28.5 1.58

*Data obtained from the National Climatic Data Center (NCDC), Station: Wenatchee Experimental Station, WA US USC00459079

Figure 5: NDCD weather reporting stations near 1000 MP 11.7 & 1040 MP 0.1

Figure 6: NCDC weather reporting stations near 3507 MP 8.0

Of note is that all weather reporting stations are at lower elevation than the repair sites, with some being further down the leeward side and may not be representative of the

Mt Adams Ranger Station

Glenwood Number 2

NCDC

Packwood Yakima 5 WSW

Leavenworth 3 S

Cle Elum

Wenatchee Experimental Station typical seasonal conditions at the sites. Characteristically, more precipitation is experienced on the western side of the Cascade Range with the moist air from the Pacific giving up the greater part its moisture as it rises over the mountains, with decreasing precipitation as distance east of the crest increases. Precipitation is typically heavy over the mountains, coming mostly as snow in winter with lowering amounts on the leeward side with increasing distance to the east. Typically, the higher elevations closest to the crests will experience higher precipitation levels and cooler temperatures.

The weather reporting stations near the NFR 1000 MP 11.7 and NFR 1040 MP 0.1 sites show the lowest average annual precipitation occurs at Yakima (8.67”) and the highest reported at Packwood (56.00”). Mean snowfall (not shown in tables) is reported at 30.0 inches at the Packwood reporting station and 57.5 inches for Glenwood Number 2.

Snowfall accumulations were not reported for the Yakima and Mount Adams reporting stations.

With respect to the 3507 MP 8.0 site, the lowest average annual precipitation was reported at the Wenatchee reporting station (9.56”) with the highest reported at Leavenworth (25.03”). Mean snowfall (not shown in tables) is reported at 33.0 inches at the Wenatchee station and 79.8 inches at the Leavenworth station. Snow accumulation was not reported for Cle Elum.

For the weather reporting stations near the FSR 1000 MP 11.7 and FSR 1040 MP 0.1 sites, of the total annual mean precipitation, between 15 percent (approximately 5 inches at the Glenwood Number 2 station) and 34 percent (about 3 inches at the Yakima reporting station) usually falls during the period April through September. For the weather reporting stations near FSR 3507 MP 8.0, the total annual mean precipitation falling between April through September is reported between 19 percent (approximately 5 inches at the Leavenworth reporting station) and 28 percent (about 3 inches at the Wenatchee station). The annual mean average precipitation (not shown in the tables) ranges from about 9 inches (Yakima) to 56 inches (Packwood) for the reporting stations near FSR 1000 MP 11.7 and FSR 1040 MP 0.1. For the reporting stations near FSR 3507 MP 8.0 the range is approximately 10 inches (Wenatchee) to 25 inches (Leavenworth). It is thought that the annual mean averages at the project sites could be near the upper reported values (and possibly higher) owing to their closer proximity to the crest of the Cascade Range and higher elevations, as compared to the reporting stations.

SITE CONDITIONS

Site vicinity maps appear as Figures 7 through 9. Descriptions of the conditions during the site visit for each site follows. Site photographs are contained in Attachment 1.

Figure 7: Site vicinity—NFR 1000 MP 11.7

Figure 8: Site vicinity—NFR 1040 MP 0.1

Figure 9: Site vicinity—NFR 3507 MP 8.0

NFR 1000 MP 11.7

(Photos 1 through 5: located at 46.520614° latitude, -121.268200° longitude) This site appears to be located in a through-fill section with a ponded area at the “cutside,” as seen in Photo 2. A heavy rainfall event caused washout of the full roadway width for approximately 100 feet long and approximately 45 feet deep. It is thought that the culvert became blocked and the embankment became saturated prior to failure. The materials at the site are predominantly granular with particles up to cobble size with possible scattered boulders.

One grab sample was collected at the face of the failure and underwent laboratory testing at the WFLHD Materials Testing Laboratory in Vancouver, WA. The laboratory test showed that the sample classified as Silty Sand with Gravel (SM) under the Unified Soil Classification System (USCS) and A-2-7(1) under the AASHTO Soil Classification System, with a Liquid Limit (LL) of 46 and a Plasticity Index (PI) of 14. Laboratory test results are provided in Attachment 2.

The site was not surveyed.

NFR 1040 MP 0.1

(Photos 6 through 11: located at 46.575111° latitude, -121.243111° longitude) The slope at this site has failed and has washed out to the inside edge of the road. The length of the failure is about 30 feet long and reaches approximately 35 feet downslope.

There is a culvert at this location that became blocked, thus concentrating water onto and over the road prior to the slope giving way. In addition, it is possible that ground saturation could have been a factor given that we observed the cutslope above the culvert inlet to be wet with seeps observed and shallow sloughing occurring during the site visit as shown in Photo 11.

Dry cutslopes to the southwest of the failure zone were observed to be over-steepened, with little to no vegetation and with eroded material accumulating at the toe of the cuts as can be seen in Photo 6. The cutslopes to the northeast of the failure were observed to be flatter and better vegetated as seen in Photo 8.

Boulders up to about 3 feet diameter were observed near the bottom of the failure as seen in Photos 6, 7, 9 and 10.

Bagged grab samples (one in the cutslope above the culvert inlet and one at the face of the failure) were collected and underwent laboratory testing at the WFLHD. The laboratory tests showed that the sample from the cutslope classifies as Clayey Sand (SC) under the USCS and A-6(3) under the AASHTO system, with a Liquid Limit (LL) of 35 and a Plasticity Index (PI) of 16. The sample from cut above the culvert inlet classified as Clayey Sand with Gravel (SC) under the USCS and A-2-4(0) under AASHTO, with a LL of 26 and a PI of 8.

This site was surveyed.

NFR 3507 MP 8.0

(Photos 12 through 18: located at 47.268278° latitude, -120.605056° longitude) The downhill slope at this site has failed for approximately 70-feet as measured along the roadway. The failure is evidenced by a slump that is approximately 4 to 5 feet lower than road grade as seen in Photos 12 through 14. Evidence of instability was observed on the downhill slope with the possible toe of the slump as seen in Photo 15; although its distance was not measured relative to the road during the site visit. The downhill adjacent natural slopes were measured at approximately 28 to 32 degrees from the horizontal.

There is a culvert located near the center of the failure, which has separated at the upper limits of the slump. See Photo 16. We did not observe active seeps and the culvert was dry during the site visit. The cutslope appeared to be stable with the natural slope above the cut measured at about 30 to 32 degrees.

We did not observe a stream at the toe of the slope or were we able to locate one using Google Earth. We interpret it likely that saturated ground was a main factor for failure with the possibility that a blocked culvert inlet and subsequent detachment contributed to surface erosion and ground saturation.

Survey was not obtained at this site and no samples were collected or tested.

RECOMMENDATIONS

NFR 1000 MP 11.7

The recommended repair at this site is to reconstruct the embankment unreinforced and to lower grade by approximately 10 feet at the culvert location. It is anticipated that lowering the grade will require the length of the repair to extend for approximately 500 feet (about 250 each side of the culvert location).

NFR 1040 MP 0.1 & NFR 3507 MP 8.0

A Reinforced Soil Slope (RSS) is proposed for the repair sites located at NFR 1040 MP 0.1 and NFR 3507 MP 8.0. RSS systems consist of planar reinforcements arranged in nearly horizontal planes in the reinforced fill to resist outward movement of the reinforced fill mass.

They are typically generic in nature and can incorporate any of a variety of reinforcements and facing systems. The RSSs for this project should incorporate geosynthetic reinforcement conforming to Section 714.04 in the FP-14 and will be faced with placed riprap.

A conceptual illustration of an RSS for the project is shown in Figure 10. Refer to the final contract plan set for specific RSS requirements for the project.

Figure 10: Conceptual Illustration for a RSS at NFR 1040 MP 0.1 & NFR 3507 MP 8.0

In addition, a shallow rock buttress (approximately 5 feet thick) that functions like a rock inlay is proposed on the uphill cut at the FR 1040 MP 0.1 repair site to control future surficial instability (sloughing) that is evident at this site. The shallow rock buttress proposed for the site is comprised of mechanically placed rock underlain by a geosynthetic filter fabric conforming to Section 714.01 in the FP-14, which will prevent future sloughed materials from that portion of the cutslope from entering the culvert inlet. A conceptual illustration for the cut-side shallow rock buttress is provided as Figure 11. Refer to the final project plan set for the specific requirements for the rock buttress.

Figure 11: Conceptual Illustration of a shallow rock buttress at FR 1040 MP 0.1

CONSTRUCTION ADVISORY

The project repair sites are in basically mountainous terrain on the east side of the crest of the Cascade Mountain Range. Accessing them will require traversing often narrow forest roads with narrow shoulders and some tight curves. Some sections of the roads are unpaved and in rough condition.

The contractor should be prepared to excavate into gravelly soils containing cobbles and possible boulders. Boulders up to 3 feet, or more, were observed at the 1040 MP 0.1 site and possibly at the 1000 MP 11.7 site, but may be present at the 3507 MP 8.0 site.

It is recommended that construction take place during the dry season at 1040 MP 0.1 where a rock buttress is planned into a shallow-sloughing cutside that exhibited seeps during the site visit in August 2017, and at the 1000 MP 11.7 site where ponded water exists and culvert replacement is anticipated.

Bedrock outcrops were not observed at the repair sites.

Laboratory tests were conducted on samples from the NFR 1040 MP 0.1 repair site. One sample was obtained from the cutside and one from the face of the failure near its upper limits. Both tested samples resulted in classifications in the USCS as SC (clayey sand or clayey sand with gravel) and in the AASHTO classification system as A-6(3) and A-2-4(0), respectively. The laboratory tests show that the material tested from the cutside, A-6(3), is not suitable to be used as unclassified borrow in embankment construction or backfill material in the RSSs on the project; however, the material from the face of the failure, A-2-4(0), was shown to be suitable for both uses.

Laboratory testing was conducted on a sample obtained from the face of the failure at NFR 1000 MP 11.7 that resulted in classifications of SM (silty sand) under the USCS and A-2-7(1) under the AASHTO system. It is expected that the excavated material from this site will be used for backfilling the culvert installation at this site. However, the Contractor should be aware that this material contains plastic silts and will likely be moisture sensitive during the compaction process. For this reason, it is recommended that construction at this site take place during the dry season. It is anticipated the excavated material taken from the upper portion of the embankment will be dryer than material taken from the lower portion.

Material from the NFR 3507 MP 8.0 site was not tested. It is assumed that this material will not meet the requirements for unclassified borrow or backfill material and should be wasted in accordance with the contract requirements.

To date, it is anticipated that culverts will need to be replaced at each of the project sites.

Since survey was not conducted at 1000 11.7 and 3507 8.0, the Contractor will be responsible for developing proposed alignments for approval by the Government.

Since no Government-provided material source is available for this project, it will be the Contractor’s responsibility to provide construction materials from a commercial or private source that meet the requirements of the contract, except at the 1000 MP 11.7 site as discussed above.

SUMMARY

This memorandum addresses the results of site reconnaissance, discussions with the project development team, USFS personnel and results of limited laboratory testing. It provides our observations, design recommendations, and construction advisories pertaining to three ERFO repair sites on Forest Service Road (FSR) 1000 at MP 11.7, FSR 1040 at MP 0.1, and FSR 3507 MP 8.0, located in the Okanogan-Wenatchee National Forest, Washington. The recommended repairs include Reinforced Soil Slopes (RSSs), embankment reconstruction, and a shallow cut-side rock buttress.

LIMITATIONS

The discussions and recommendations appearing herein are based on our understanding of the current conditions of the sites and general vicinity, our understanding of similar failures in the region, and professional judgement. They are intended only for the repair sites discussed in this memorandum and are not to be applied to any other site or used for any other purpose.

For questions regarding this memorandum, please contact Geotechnical Engineer, Robert Kraig, at 360-619-7699 or robert.kraig@dot.gov. If soil or ground conditions are encountered during construction that vary from those discussed in this report, the WFLHD Geotechnical Team should be notified immediately in order to evaluate what effects, if any, the changes have on the recommendations contained in this report.

mailto:robert.kraig@dot.gov

Attachment I Project Photographs

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Photo 1: 1000 MP 11.7 looking ahead to failure zone.

Photo 2: 1000 MP 11.7 “Cutside” at failure zone (looking to the right in Photo 1).

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Photo 3: 1000 MP 11.7 looking at far side of failure zone.

Photo 4: 1000 MP 11.7 looking at near side of failure zone.

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Photo 5: 1000 MP 11.7 looking downslope into failure zone.

Photo 6: 1040 MP 0.1 looking into failure zone

Over steepened cutslope

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Photo 7: 1040 MP 0.1 looking into failure zone.

Photo 8: 1040 MP 0.1 looking into failure zone. Note sloughing cutslope.

5 | P a g e

Photo 9: 1040 MP 0.1 looking into failure zone. Note culvert pipe.

Photo 10: 1040 MP 0.1 looking down failure. Note culvert pipe.

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Photo 11: 1040 MP 0.1 note sloughing cutslope

Photo 12: 3507 MP 8.0 looking across slumped zone

Wet, shallow sloughing

Shoulder slump

7 | P a g e

Photo 13: 3507 MP 8.0 looking across slumped zone

Photo 14: 3507 MP 8.0 looking down into the slumped zone

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Photo 15: 3507 MP 8.0 Possible toe of slump.

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Photo 16: 3507 MP 8.0 Outlet side of separated culvert

Photo 17: 3507 MP 8.0 separated culvert

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Photo 18: 3507 MP 8.0 outlet side of separated culvert.

Attachment II Laboratory Test Results

(Intentionally blank)

Robert.Kraig Text Box 1000 11.7

1040 0.1

1040 0.1