B08_Attach_21_MEVE_218998_FIO_Rehab_Chapin_Mesa_Final_Geotech_Report_2023_11_30.pdf

GEOTECHNICAL INVESTIGATION

Chapin Mesa Village Historic District

Mesa Verde National Park Mesa Verde, Colorado

Yeh Project No.: 222-342

November 30, 2023

Prepared for:

Hennebery Eddy Architects, Inc.

921 Washington Street, Suite 250

Portland, Oregon 97205

Prepared by:

Yeh and Associates, Inc.

570 Turner Drive, Suite D

Durango, CO. 81303 Phone: 970-382-9590

GEOTECHNICAL INVESTIGATION

Chapin Mesa Village Historic District Mesa Verde National Park

Mesa Verde, Colorado

Yeh Project No.: 222-342

November 30, 2023

Prepared by: Reviewed by:

Samantha C. Sherwood, P.E. T. Samuel Holder, P.E.

Senior Project Manager Senior Project Manager i

TABLE OF CONTENTS

1.0 PURPOSE AND SCOPE OF STUDY

2.0 PROJECT DESCRIPTION AND HISTORY

3.0 GEOLOGIC SETTING AND SITE CONDITIONS

3.1 GEOLOGIC SETTING

3.2 SITE CONDITIONS

MUSEUM

BUILDINGS 1 AND 2

BUILDING 3

BUILDING 4

BUILDING 5

BUILDING 6

BUILDING 7

BUILDING 8

4.0 SUBSURFACE INVESTIGATION

4.1 FIELD EXPLORATION

4.2 GEOPHYSICAL SURVEY

4.3 LABORATORY TESTING

5.0 SUBSURFACE CONDITIONS

5.1 PAVEMENT BORINGS

5.2 HAND AUGER BORINGS

5.3 GROUNDWATER CONDITIONS

6.0 EARTHWORK

6.1 EXCAVATION AND TRENCH CONSTRUCTION

6.2 STRUCTURAL FILL REQUIREMENTS

6.3 COMPACTION REQUIREMENTS

6.4 DRAINAGE CONSIDERATIONS

7.0 STRUCTURE STABILIZATION RECOMMENDATIONS

8.0 FLOOR SLAB DESIGN AND CONSTRUCTION

8.1 INTERIOR SLABS

8.2 EXTERIOR SLABS

9.0 ADDITIONAL REMEDIAL MEASURES

9.1 PLUMBING INTEGRITY TESTING

9.2 MONITORING

10.0 SEISMIC CONSIDERATIONS

ii

11.0 PAVEMENT RECOMMENDATIONS

11.1 TRAFFIC LOADING

11.2 EXISTING PAVEMENT AND SUBGRADE CONDITIONS

11.3 ASPHALT PAVEMENT

11.4 ASPHALT CONCRETE PAVEMENT MIXES

11.5 PAVEMENT DESIGN CONSIDERATIONS

12.0 CORROSION POTENTIAL

13.0 LIMITATIONS

LIST OF APPENDICES

APPENDIX A – BORING LOCATION PLAN

APPENDIX B – BORING LOGS AND LEGEND

APPENDIX C – LABORATORY TEST RESULTS

APPENDIX D – OLSON GEOPHYSICS REPORT

APPENDIX E – PAVEMENT DESIGN

Chapin Mesa Village Historic District Yeh Project No. 222-342 Mesa Verde National Park November 30, 2023

1.0 PURPOSE AND SCOPE OF STUDY

This report presents the results of our geotechnical investigation for a portion of the Chapin Mesa

Village Historic District at Mesa Verde National Park. This investigation was performed in general accordance with our Proposal No. 222-342 dated August 29, 2022 and Amendment 1 dated August 9, 2023. Our scope of services included a site reconnaissance, field exploration with geophysics, laboratory testing, geotechnical engineering analyses, and preparation of this report.

The purposes of this investigation were to evaluate the subsurface conditions on the site and to develop geotechnical recommendations to stabilize the existing structures and mitigate future movement and provide recommendations for pavement rehabilitation. Our scope of services included the following:

• A site reconnaissance by a geotechnical engineer to observe the conditions at the site.

• Drilling soil borings for pavement evaluation and excavating test holes with a hand auger to evaluate the subsurface conditions at the building locations.

• Geophysical survey to assess depth to bedrock and GPR survey of utilities.

• Laboratory testing to evaluate pertinent engineering properties of the site soil.

• Providing recommendations for the design of shallow foundations for use in supporting the existing structures.

• Providing recommendations for reducing the potential for variations in the water content of the deposits underlying the buildings.

• Providing recommended asphalt pavement sections and pavement subgrade preparation recommendations.

• Providing recommended flatwork sections and flatwork subgrade preparation recommendations.

• Providing earthwork recommendations, including recommendations for fill placement and compaction, suitability of the site soil for reuse as engineered fill, and subgrade preparation.

2.0 PROJECT DESCRIPTION AND HISTORY

The Chapin Mesa Village Historic District is in southwestern Colorado, approximately 30 miles southeast of Cortez (Figure 1). The project consists of eight residential structures and the museum. The buildings were constructed in the early 1920s using blocks cut from the native sandstone and mortar, with minimal or no foundations bearing on the sandstone. These structures have experienced movement over time, which has caused varying degrees of distress, including cracked and tilting floor slabs, cracks in the exterior and interior walls. Details of our observations and photographs are included in Section

3.2 Site Conditions.

Figure 1. Project Site

3.0 GEOLOGIC SETTING AND SITE CONDITIONS

3.1 Geologic Setting

The project area is mapped by the United States Geological Survey as Cliff House Sandstone (Kch) of

Upper Cretaceous age. The Cliff House Sandstone is the youngest, and therefore upper, member of the

Mesaverde Group. In the southern part of the park, where the project area lies, this unit consists of two massive, fine to medium grained, cross-bedded cliff forming sandstone separated by a softer, thin sandy shale. The sandstones are generally white, yellowish-orange, brownish-yellow, and pale brown. Iron concretions are common and are usually about 0.5 to 2 inches in diameter. Near the project area, this unit typically weathers into a polygonal pattern of grooves referred to as “turtlebacks.” The maximum thickness of the Cliff House unit recorded in the southern portion of the park is about 395 feet.

East of the project area is mapped as Loess (Qlo) of Holocene and middle Pleistocene age. This unit consists of reddish-brown to yellowish-red fine sandy silt and silt deposited by wind, and rests unconformably on the Cliff House Sandstone. It forms a continuous blanket on many mesa surfaces and is estimated to be about 5 to 15 meters thick. West of the project area, along the steep mesa cliffs and the valleys between, the USGS mapped Colluvial deposits derived from the Menefee Formation (Qcmf) of Holocene to late Pleistocene age. This colluvium generally consists of cobbly boulder gravel deposited by mass wasting processes, predominantly by creep. It includes gray clayey silt and pale

Site brown silty fine sand containing white angular to subangular sandstone pebbles, cobbles and boulders. This colluvial unit is estimated to be about 65 feet thick. Translational and rotational landslide deposits (Qtr) of Holocene and late Pleistocene age are mapped in the valleys surrounding the project area and are generally derived from the Menefee Formation and Mancos Shale. Oligocene minette dikes (Tm) are also mapped near the project area.

Figure 2. Geologic Map of the Project Area

3.2 Site Conditions

The project consists of eight residential sandstone structures and the museum building. Reconnaissance of Buildings 1-8 and the museum in general found little evidence of settlement. Many of the walls are visibly built on top of sandstone bedrock without concrete footings or foundations. Various amounts of staining on sandstone blocks and lichen growth are present on all buildings. This is primarily seen around windows, parapets, and the west side of the buildings near ground level. Exterior wall cracks have been identified on all buildings except for Buildings 1 and 2. These cracks are primarily in the mortar between blocks. Mortar deterioration and spalling is present in covered areas and the interior of

Buildings 5 and 6. However, mortar on most exterior walls is in good condition.

Museum

Mortar spalling and general deterioration is present in the enclosed portion of exterior walls near the main and west side entrances. Cracking is present on both sides of the lower one to two feet of the museum’s SE corner. Furthermore, blocks in this section have begun to separate from the wall. Minor possible settlement was observed this location. Block discoloration and lichen growth are present in localized areas of apparent high moisture around the building.

Figure 3. Mortar Deterioration and Spalling Near Museum Entrance

Figure 4. Mortar Deterioration, Spalling at West Employee Entrance

Figure 5. Open Crack on South Side of SE Corner

Figure 6. Apparent Water Damage and Missing Mortar Central East Window

Buildings 1 and 2

Buildings 1 and 2 appeared generally in good condition. No items of concern were identified during our reconnaissance.

Figure 8. Building 2, West Side

Building 3

The exterior walls appeared in good condition with no noticeable settlement, cracks, mortar spalling, or signs of excessive moisture. The front porch had a separation crack that does not appear to be the result of settlement, however, frost heave following water infiltration between blocks is possible.

Figure 7. Building 1, SW Corner

Figure 9. Building 3, South Side

Figure 10. Building 3 Porch Blocks

Building 4

The exterior walls of Building 4 appeared to be in good condition with no obvious settlement, mortar spalling, cracking, or excessive water damage. The north side patio has several cracks across its width and length. A concrete patch is visible in the center of the patio. Observed settlement was less than one inch in all areas.

Figure 11. Building 4, Cracking and Settlement of North Patio

Building 5

Exterior observations identified signs of moisture and a running crack under the central east window.

The building’s interior had been partly stripped, with the floor and some of the walls removed revealing the building’s foundation. Building 5 was built directly on bedrock without concrete footings. The interior was in very poor condition with extensive water damage to the ceiling and walls. Mortar on the interior side of the exterior walls was deteriorated and spalling. Cracking in plaster and peeling of paint was observed on all walls with damage more prevalent near windows and wall corners. There was evidence of rodent infestation, with thick dropping piles and rodent holes through and under the walls in every room.

Figure 12. Building 5, Mortar Separation from Blocks at East Window

Figure 12. Building 5, Interior Damage

Figure 13. Building 5 Exposed Bedrock Surface

Building 6

Exterior observations identified signs of moisture penetration in various places. The north side patio was cracked with settlement up to 3” observed along the buried utility line. Like Building 5, the interior of the building had been partially stripped, with the floor and some of the walls removed to reveal the building’s foundation. Building 6 was also constructed directly on bedrock. More modern concrete footings had been installed to support the interior walls.

The interior of the building was in very poor condition with water damage to the ceiling and walls.

Mortar on the interior side of the exterior walls was deteriorated and spalling. Cracking in plaster and peeling of paint was also observed on all walls. This damage was more prevalent near windows and wall corners. There was also evidence of rodent infestation as thick dropping piles and rodent holes through and under the walls were observed in every room.

Figure 14. Building 6, Block Staining and Lichen Growth North Side Exterior

Figure 16. Building 6, North Side Patio Cracks, Settlement Along Buried Utility

Figure 17. Building 6, Bedrock at Surface

Figure 15. Building 6, Mortar Deterioration, Spalling at Floor Level

Building 7

Signs of excessive moisture were present throughout the exterior of the building. A previously monitored crack was identified under the SE wall window. Minor cracking in the mortar is also present above the garage and west wall. Significant water damage is present in the basement stair well with calcium residue near the bottom. The ceiling of the stair well was separating from the porch above.

Apparent mortar repair was identified on the west wall near ground level.

Figure 16. Building 7, Crack Formed Above Garage

Figure 17. Building 7 Basement Stairwell Water Damage

Figure 18. Building 7, Basement Stairwell Ceiling Damage

Figure 19. Building 7, West Wall Mortar Repair

Figure 20. Building 7, Crack Monitor on Southeast Wall

Building 8

Multiple cracks were identified on exterior walls of Building 8. The most significant crack was located at the corner of the tower and west wall running the full length of the joint. Signs of high moisture penetration are located primarily on the west side near the ground.

Figure 21. Building 8, West Wall Joint Cracking

Figure 22. Building 8, North Window Cracking

4.0 SUBSURFACE INVESTIGATION

4.1 Field Exploration

Hand auger borings were drilled immediately adjacent to the buildings to determine the soil conditions adjacent to the building foundations. The borings were drilled/hand excavated to the bottom of the footings and then angled so that the material beneath the footings could be sampled. These borings were terminated at depths ranging from 6 inches to 3 feet.

Six pavement borings were advanced using a CME 55 drill rig with 4-inch outside diameter (OD) hollow-stem, continuous flight auger. At selected intervals, a standard split spoon sampler with a 1⅜-inch ID and 2-inch OD was driven to record blow counts and obtain samples. The split spoon sampler was seated at the bottom of the boring, then advanced by an automatic hydraulic hammer of 140 pounds falling 30 inches. The number of blows (blow count) required to drive the sampler 12 inches or a fraction thereof, constitutes the N-value. The N-value, when properly evaluated, is an index of the consistency or relative density of the material tested. Bulk samples of drill cuttings were also obtained in the upper 5 feet. Boring logs and legend are presented in Appendix B.

The drilling operations were monitored by a Yeh and Associates engineer. Yeh personnel prepared field logs documenting the subsurface conditions encountered, groundwater levels, standard penetration test blow counts (N-values), sampling intervals, and types of samples obtained. The field logs were used by the project geotechnical engineer as an aid in preparing the final boring logs. Copies of the boring logs are presented in Appendix B.

4.2 Geophysical Survey

A geophysical survey was performed by Olson Engineering using ground penetrating radar (GPR) and

Spectral Analysis of Surface Waves (SASW) methods to evaluate the depth of the overburden soils around the structures. The results of the survey generally support the soil sampling data, with sandstone bedrock identified at relatively shallow and varied depths. Softer lenses of sandstone and decomposed shales may be interpreted as overburden soils, as evidenced by the depth to bedrock identified in the area of Building 6, where bedrock is exposed beneath the floor inside the building but indicated to be at about 11 feet in the geophysical survey. The geophysical survey report is presented in

Appendix D.

A GPR survey was also conducted to identify the location of underground utilities at the residences. A map of the utilities is provided in Appendix D.

4.3 Laboratory Testing

The recovered soil samples were classified by the project geotechnical engineer in accordance with the

Unified Soil Classification System (USCS). Laboratory tests were then performed to evaluate the pertinent engineering properties of the soil. The laboratory testing was conducted in general accordance with the

American Society for Testing and Materials (ASTM) test procedures. The following laboratory tests were performed for this evaluation:

• Water Content

• Percent Passing No. 200 Sieve

• Atterberg Limits

• R-Value

• Water Soluble Sulfates and Chlorides

The laboratory test results are presented on the boring logs and summarized in Appendix C.

5.0 SUBSURFACE CONDITIONS

5.1 Pavement Borings

These borings encountered variable layers of sandstone, clayey sand, silty sand and clay (derived from decomposed sandstone and shale) to the maximum depth explored of 11.5 feet. Auger refusal was met in Borings P-1 at 5.8 feet and P-5 at 9.2 feet. In addition, processed sandstone fill was encountered in

Borings P-4 and P-5 to depths of approximately 10 feet below the existing pavement. The measured asphalt thicknesses ranged from 2½ to 4¼ inches.

5.2 Hand Auger Borings

Hand auger borings/test pits were excavated immediately adjacent to select buildings to determine the type of or depth of soil supporting the foundations. The soils encountered typically consisted of clays and clayey to silty sand, overlying shallow sandstone. The hand auger borings/test pits were terminated due to auger refusal at depths of approximately 6 inches to about 3 feet.

5.3 Groundwater Conditions

Groundwater was not encountered in the borings at the time of our investigation. Variations in groundwater conditions may occur seasonally. The magnitude of the variation will be largely dependent on duration and intensity of precipitation, site grading changes, and the surface and subsurface drainage characteristics of the surrounding area.

6.0 EARTHWORK

6.1 Excavation and Trench Construction

Utility excavations will likely encounter a variety of conditions with potential for very shallow sandstone bedrock. All excavations must comply with the applicable local, State, and Federal safety regulations, and particularly with the excavation standards of the Occupational Safety and Health Administration

(OSHA). Construction site safety, including excavation safety, is the sole responsibility of the Contractor as part of its overall responsibility for the means, methods, and sequencing of construction operations.

The information contained herein is provided for the Client’s sole use in planning the project, and in no way do they relieve the Contractor of its responsibility to construct, support, and maintain safe slopes.

Under no circumstances should the following recommendations be interpreted to mean that Yeh is assuming responsibility for either construction site safety or the Contractor’s activities.

We believe the bedrock encountered on this site will classify as a Type A material, using OSHA criteria.

OSHA requires that unsupported cuts be no steeper than 3/4h:1v for Type A materials in unbraced excavations up to 20 feet in height. In general, we believe that these slope ratios will be temporarily stable under unsaturated conditions. Flattened slopes or shoring may be required if excavations encounter groundwater or the slopes will be exposed for an extended period. Please note that the

Contractor’s OSHA-qualified “competent person” must make the actual determination of soil type and required sloping in the field.

It is recommended that all vehicles and soil piles be kept to a lateral distance equal to at least the depth of the excavation from the crest of the slope. The exposed slope face should be protected against the elements and monitored by the contractor on at least a daily basis.

6.2 Structural Fill Requirements

Imported fill used for structural elements should consist of a non-expansive granular material meeting the criteria presented in Table 1 below.

Table 1 – Import Structural Fill Requirements

Gradation Requirements

Standard Sieve Size Percent Passing

2-inch 100

No. 200 0-30

Plasticity Requirements (Atterberg Limits)

Liquid Limit 30 percent or less

Plasticity Index 6 or less

We recommend that a representative of Yeh and Associates visit the site during excavation to verify the soils exposed in the excavations are consistent with those encountered during our subsurface exploration and that proper foundation subgrade preparation is performed. A sample of any imported fill material, if required, should be submitted to our office for approval.

6.3 Compaction Requirements

All fill should be placed in horizontal lifts compatible with the type of compaction equipment being used, moisture conditioned, and compacted in accordance with the criteria shown in Table 2.

Table 2 – Subgrade Preparation and Fill Placement Criteria

Fill Location Material Type Percent Compaction (ASTM Method)

Moisture Content

Building Foundations and Slabs on Grade;

Pavement and Flatwork Subgrade Soils

On Site Soils (Clays, Sands)

95 minimum (ASTM D698) 0 to 3% above OMC

Imported Granular Structural Fill

95 minimum (ASTM D1557) ± 2% of OMC

Trench Backfill

On Site Soils (Clay, Sand and Gravel)

95 minimum (ASTM D698) 0 to 3% above OMC

Imported Granular Structural Fill

95 minimum (ASTM D1557) ± 2% of OMC

Aggregate Base Course Imported Class 5 or 6

Aggregate (See Section 12.5.1)

95 minimum (ASTM D1557) ± 2% of OMC

Fill should be placed in level lifts not exceeding 8 inches in loose thickness and compacted to the specified percent compaction to produce a firm and unyielding surface. If field density tests indicate the required percent compaction has not been obtained, the fill material should be reconditioned as necessary and re-compacted to the required percent compaction before placing any additional material.

6.4 Drainage Considerations

Positive drainage should be created and maintained to route surface water away from the buildings.

Drainage design should prevent ponding water immediately adjacent to the structure and roof run-off should be captured and routed away from the building. We recommend the ground surface should be sloped away from the building at a minimum of two percent for a minimum distance of 10 feet.

We understand a perimeter foundation drain is being considered for each of the structures. It should be noted that the buildings are generally constructed on the sandstone bedrock with interbedded layers of sand and clay. Excavation of the rock adjacent to the existing structures should be performed with caution. Saw-cutting of the rock is recommended to minimize vibration disturbance to the existing structures. Once the trench is excavated, the burrito-style drain should consist of a 4” perforated pipe bedded in free-draining gravel, wrapped in a geotextile filter material. The drains must maintain a positive slope to move water away from the structures.

7.0 STRUCTURE STABILIZATION RECOMMENDATIONS

The residential buildings and the museum are founded on sandstone interbedded with layers of sand, clay and silty sand (decomposed bedrock). We believe that both the sandstone and soil-like layers within the sandstone are susceptible to erosion from moisture and extreme weather conditions. To repair the stacked stone walls and foundations, we recommend the sandstone walls be repointed.

Additionally, we recommend consideration of a low-pressure polyurethane resin (PUR), epoxy or grout injection to stabilize the blocks and prevent further weathering.

Figure 23. Building 5 Stone Stem Wall with Mortar Decay

Concrete footing foundations may also be used to support the portions of the structures. Shallow foundations should be designed using the maximum allowable bearing pressure of 2,500 pounds per square foot (psf) for spread footings. The allowable bearing pressure is based on a factor of safety

(F.O.S.) of approximately three (3) with respect to shear failure of the foundation bearing materials. A one third increase in the allowable bearing pressure may be used for the maximum allowable bearing pressure for temporary loading conditions including wind or seismic conditions.

Continuous wall footing should have a minimum width of 16 inches, and isolated spread footings should have a minimum width of 24 inches.

All exterior footings or footings below unheated portions of the structure should be placed a minimum of 3 feet below the final exterior grade to provide protection against frost penetration. Interior footings should bear a minimum of 24 inches below finished grade. The finished grade is the lowest adjacent grade for perimeter footings and floor level for interior footings. Footings should be proportioned to reduce differential foundation movement. Proportioning on the basis of equal total movement is recommended; however, proportioning to relative constant dead load pressure will also reduce differential movement between adjacent footings.

Foundations should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. The use of joints at openings or other discontinuities and at periodic intervals on long masonry walls is recommended.

Foundation excavations should be observed by the geotechnical engineer or engineer’s representative.

If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations will be required.

8.0 FLOOR SLAB DESIGN AND CONSTRUCTION

The project will include partial and/or complete replacement of damaged floor slabs. Slabs on grade may be constructed on the bedrock or a thin leveling course of structure backfill. Recommendations for interior and exterior slabs are provided below.

8.1 Interior Slabs

For structural design of concrete slabs-on-grade, a modulus of subgrade reaction of 200 pounds per cubic inch (pci) may be used for floors supported on 4 inches or more of non-expansive, compacted granular fill over the sandstone bedrock.

Additional floor slab design and construction recommendations are as follows:

• Landscaped irrigation and roof run-off should be minimized or eliminated adjacent to the foundation system and the building.

• Positive separations and/or isolation joints should be provided between slabs and all foundations, columns, or utility lines to allow independent movement.

• Frequent control joints should be provided in slabs to control the location and extent of cracking.

• Interior trench backfill placed beneath slabs should be compacted in accordance with recommended specifications outlined herein.

• If moisture-sensitive floor coverings are used on interior slabs, consideration should be given to the use of vapor barriers to minimize potential vapor rise through the slab.

• Floor slabs should not be constructed on frozen subgrade.

• Other design and construction considerations, as outlined in Section 302.1 R of the "ACI

Design Manual” are recommended.

8.2 Exterior Slabs

Movement of exterior slabs can occur from heave due to frost or settlement of subgrade soils, particularly over utilities. Exterior slab movement can result in off-sets, tilting, and cracking. We recommend exterior flatwork, including sidewalks, be isolated from foundations to reduce the risk of the movement being transferred to the structure. Additionally, movement and cracking may affect the appearance and performance of the slabs and can affect the slab’s compliance with ADA requirements.

Some considerations that may improve slab appearance and performance are presented below:

Placement of 2 to 3 feet of granular engineered fill beneath exterior flatwork can be considered to mitigate frost susceptible clayey and silty sands. This optimum thickness may be limited by the presence of shallow bedrock. Backfill should be moisture-conditioned and compacted as discussed in Section 5.

Frequent control joints should be provided to reduce damage associated with shrinkage.

Approximately square panels perform better than rectangular panels.

Moisture infiltration to the subgrade is one of the key elements that leads to problems.

Elimination of irrigation around the exterior slabs, directing roof discharges away from these slabs, and preventing snow accumulation adjacent to the slabs can reduce the risk of movement.

Use of plants that do not require irrigation will help absorb the moisture beneath the exterior slab without creating large root masses, which can cause slab movement.

9.0 ADDITIONAL REMEDIAL MEASURES

Improving site drainage through grading, and other means of diverting water away from the buildings is recommended to reduce moisture variations in the soils and bedrock, leading to additional decomposition. These measures may reduce, but not eliminate, the potential for movement. If the drainage measures are altered, overloaded, or fail, or if water is introduced to the floor slab subgrade through utility line leaks or other measures, floor slab movement could occur over time.

The following additional measures are recommended to reduce erosion of the soils and bedrock, and potential for structural movement.

9.1 Plumbing Integrity Testing

Movement associated with the soils and bedrock erosion could have been hastened by leaks in water supply and drain lines. Leaks in these lines could introduce water into the deposits underlying the structures causing erosion and settlement of the soils and bedrock. It is therefore recommended that the water supply and drain lines be tested to check their integrity. Any leaks that are detected should be repaired.

9.2 Monitoring

A monitoring program could be implemented if measures are not taken to reduce the potential for foundation/floor slab movement. Crack monitors and foundation/floor slab elevation surveys could be initiated to check whether the building foundations/floor slabs are experiencing continued movement. If the monitoring program indicates that movement is not occurring, underpinning and other remedial measures are not required.

10.0 SEISMIC CONSIDERATIONS

Seismic structural design criteria were developed using the ASCE 7 Hazard Tool. The parameters are provided below:

Design Code Reference ASCE7-22

Site Soil Classification: Site Class C*

GPS Coordinates: 37.184663, -108.489392

Ss = 0.15 g SMS = 0.16 g SDS = 0.11 g

S1 = 0.04 g SM1 = 0.055 g SD1 = 0.036 g

* The site class was based on the conditions encountered in our shallow exploratory soil borings data from the geophysical survey, and our knowledge of the soil conditions in the vicinity of the site. The soil characteristics extending beyond the depth of our borings were assumed for the purposes of providing this site classification.

11.0 PAVEMENT RECOMMENDATIONS

11.1 Traffic Loading

The project scope is also to address the reconstruction of a number of access drives.

Anticipated traffic volumes were not provided for our analysis. However, it was assumed that the pavement would be subject to automobile and light truck traffic, with occasional moderately loaded delivery vehicle traffic. For pavement traffic loading we will follow the guidelines in the FHWA Central Federal Lands Project Development and Design Manual

(PDDM). For low volume pavement designs with no traffic data, a design life of 20 years with a loading of 50,000 equivalent single axle loads (ESAL) will be used.

11.2 Existing Pavement and Subgrade Conditions

The existing pavement condition varied from fair to poor, depending on location. There are numerous cracks, both linear thermal and longitudinal cracks as well as locations with moderate fatigue (alligator) cracking. In addition to the variable conditions, there are numerous stone curbs, retaining walls and other paved segments that will need to be considered and matched for each pavement’s reconstruction.

As shown in the Boring Location Map, the borings are located on several access roads. The pavement thickness in these borings is presented in Table 2.

Table 2 – Existing Pavement Thickness and Bulk Soils

Boring

Number

Pavement

Thickness, in, Bulk Soil

Classification

YA-P1 3.5 A-6(2)

YA-P2 3.0 A-1-b(0)

YA-P3 4.25 A-6(6)

YA-P4 2.5 A-1-b(0)

YA-P5 2.5 A-2-4(0)

YA-P6 4.0 A-6(7)

As shown in the boring logs, most of the paved roads do not contain aggregate base beneath the pavement. As presented in Table 2 and in the boring logs the soils beneath the pavements are quite variable, ranging from relatively low plasticity clay soils to silty sand, CL, SC and SM.

The boring logs also show that some pavement appears to have been placed almost directly on sandstone.

The bulk A-6 soil samples from YA-P3 and YA-P6 were combined to test for R-value. The resulting R-value was 14. The R-value of 14 was used to calculate a resilient modulus (MR) of

8,770 psi using Equation 1.5.3 from the 1993 AASHTO Pavement Design Guide. This MR value will be used to represent the subgrade strength in the pavement design program.

The soil plastic indices (PI) ranged from non-plastic to PI = 18 on two samples. The fines content ranged from 19.4 to 54.6 percent. No Swell/Consolidation tests were performed on the pavement boring samples.

11.3 Asphalt Pavement

We believe that for future reconstruction of these pavements, several options using asphalt concrete pavement (ACP) should be considered. These options should be site specific since the pavements are separated and have different requirements of existing pavement that may need to be matched and there are many sections with retaining walls or stone curbs, also pavement rise needs to be considered because of drainage requirements and matching other pavement and to not bury existing curbs or retaining walls. Table 3 presents pavement options that could be considered as well as removals required to address pavement rise. We believe that the minimum FHWA minimum ACP thickness of 3 inches should be maintained.

The structural number calculated based on the measured R-value and the 50,000 ESAL is 1.79.

There are numerous combinations of pavement and base or pavement and Full Depth

Reclamation (FDR) material that could be used to meet the structural number requirements.

Table 3 - Recommended Asphalt Pavement Sections

Treatment Option

Asphalt

Pavement

(in.)

Aggregate Base

Couse (in.)

Removal

Required*

(in.)

Pavement

Rise (in.)

Removal and Full Depth ACP 4.25 0 4.25 0

Removal with ABC 3.0 4.0 7 0

FDR to 6 inches 3 4 4 3

FDR to 6 inches 3.5 3 3 2

*Removal of materials include existing pavement and the soils below or FDR material after processing.

Pavement design program outputs addressing the thicknesses in Table 3 are presented in

Appendix D.

11.4 Asphalt Concrete Pavement Mixes

The ACP pavements should be constructed using nominal ½ or nominal ¾ inches mixes with asphalt binder grade PG 58-28. We recommend using a gyratory mix design meeting the requirements mix requirements for a 75-gyration mix. Following the pavement design printouts in Appendix D, the output from the FHWA Long Term Pavement Program (LTPP) recommendations for the asphalt binder are presented.

11.5 Pavement Design Considerations

The pavement should be sloped to ensure positive drainage. Water should not pond in areas directly adjoining paved sections. The site soils are expansive and differential heave may occur.

The pavement service life may be reduced due to water infiltration into the subgrade soils. This will result in a softening and loss of strength of the subgrade soils. A regular maintenance program to seal pavement cracks will help prolong the life of the pavement.

The pavement surface and adjacent areas should be well drained. Excessive watering of landscaped areas adjacent to pavements should be avoided. Proper maintenance should be performed on cracks in the pavement surface to prevent water from penetrating through to the base or subbase material.

12.0 CORROSION POTENTIAL

Water-soluble sulfates were measured in the laboratory on two representative samples of the soils.

The concentration of water-soluble sulfates measured in the laboratory ranged from 0.001 to 0.004 percent. This concentration of water-soluble sulfates represents a Class 0 degree of sulfate attack on concrete exposed to these geologic materials. The degree of attack is based on a range of Class 0

(negligible) to Class 3 (very severe) as described in the American Concrete Institute (ACI Standard

201.2R, “Guide to Durable Concrete.”

13.0 LIMITATIONS

The recommendations in this report are based on our field observations, laboratory testing, and our present understanding of the proposed construction. It is possible that subsurface conditions can vary beyond the limits explored. If the conditions found during construction differ from those described in this report, please notify us immediately so that we can review our report considering those conditions and provide supplemental recommendations as necessary. We should also review this report if the scope of the proposed construction, including the proposed loads or structure locations, changes from that described in this report.

The scope of services for this project did not include, specifically or by implication, any environmental or biological (e.g. mold, fungi, and bacteria) assessment of the site or identification or prevention of pollutants, or conditions or biological conditions. If the owner is concerned about the potential for such contamination, conditions or pollution, other studies should be undertaken and a professional in that field should be consulted.

Yeh and Associates has prepared this report for the exclusive use of the Henneberry Eddy Architects and the National Park Service. This report was prepared in substantial accordance with the generally accepted standards of practice for geotechnical engineering as they exist in the site area at the time of our investigation. No warranty is expressed or implied. The recommendations in this report are based on the assumption that Yeh and Associates will conduct an adequate program of construction testing and observation to evaluate compliance with our recommendations.

Appendix A

BORING LOCATION PLAN

YA-HA-1

YA-P-1

YA-P-2

YA-P-3

YA-P-4

YA-P-5

YA-HA-1A

YA-HA-2

YA-HA-2A

YA-HA-3

YA-HA-3A

YA-HA-3BYA-HA-4

YA-HA-4A

YA-HA-4B

YA-HA-6

YA-HA-6A

YA-HA-6B YA-HA-5

YA-HA-5A

YA-HA-5B

YA-HA-8

YA-HA-8A

YA-HA-8B

YA-HA-7

YA-HA-7A

APPROXIMATE BORING LOCATION

PROJECT NUMBER:

SCALE

SHEET REVISION DATEBY

OF

SHEET

& Associates, Inc.

project without written authorization from Yeh service and shall not be used for any other document are instruments of professional

Associates, Inc. The ideas incorporated on this

This document is the property of Yeh &

REUSE OF DOCUMENT

DRAWN BY:

CHECKED BY:

DATE:

DATE:

HORIZ: VERT:

NO.

DESIGNED FOR:

1:80

12/1/2023

12/1/2023

Yeh and Associates, Inc.

Geotechnical · Geological · Construction Services

MJW

SCS

NATIONAL PARK SERVICE

222-342

STRUCTURE REHAB

CHAPIN MESA HISTORIC

BORING LOCATION PLAN

40'0' 20' 80'

APPROX. SCALE

ARCHEOLOGICAL MUSEUM

CHAPIN MESA

PARK HEADQUARTERS

MESA VERDE

M E

S A

T O

P

R U I N

S

R D

YA-HA-7B

YA-P-6

Appendix B

BORING LOGS AND LEGEND

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Project Number: 222-342

Sample Types Legend for Symbols Used on Borehole Logs

Project:

3. The Modified California sampler used to obtain samples is a 2.5-inch OD, 2.0-inch ID (1.95-inch ID with liners), split-barrel sampler with internal liners, as per ASTM D3550. Sampler is driven with a 140-pound hammer, dropped 30 inches per blow.

2. "Penetration Resistance" on the Boring Logs refers to the uncorrected N value for SPT samples only, as per ASTM D1586. For samples obtained with a Modified California (MC) sampler, drive depth is 12 inches, and "Penetration Resistance" refers to the sum of all blows. Where blow counts were > 50 for the 3rd increment (SPT) or 2nd increment (MC), "Penetration Resistance" combines the last and 2nd-to-last blows and lengths; for other increments with > 50 blows, the blows for the last increment are reported.

Lab Test Standards

1. Visual classifications are in general accordance with ASTM D2488, "Standard Practice for Description and Identification of Soils (Visual-Manual Procedures)".

Bulk Sample of auger/odex cuttings

Standard Penetration Test

(ASTM D1586)

Drilling Methods

4. "ER" for the hammer is the Reported Calibrated Energy Transfer Ratio for that specific hammer, as provided by the drilling company.

pH Soil pH (AASHTO T289-91) S Water-Soluble Sulfate Content (AASHTO T290-91, ASTM D4327)

Chl Water-Soluble Chloride Content (AASHTO T291-91, ASTM D4327)

S/C Swell/Collapse (ASTM D4546) UCCS Unconfined Compressive Strength

(Soil - ASTM D2166, Rock - ASTM D7012) R-Value Resistance R-Value (ASTM D2844) DS (C) Direct Shear cohesion (ASTM D3080) DS (phi) Direct Shear friction angle (ASTM D3080) Re Electrical Resistivity (AASHTO T288-91) PtL Point Load Strength Index (ASTM D5731)

Lithology Symbols

Asphalt Boulders Clayey Sand (SC) Lean Clay (CL)

Sandstone Sandy Lean Clay

(CL)

Silty, Clayey Sand

(SC-SM)

Well-Graded Sand with Clay (SW-SC)

Sandstone

(see Boring Logs for complete descriptions)

Other Lab Test Abbreviations

Notes

HAND AUGER HOLLOW-STEM

AUGER

Fill

Moisture Content ASTM D2216 Dry Density ASTM D7263 Sand/Fines Content ASTM D421, ASTM C136, ASTM D1140

Atterberg Limits ASTM D4318 AASHTO Class. AASHTO M145, ASTM D3282

USCS Class. ASTM D2487 (Fines = % Passing #200 Sieve Sand = % Passing #4 Sieve, and retained on the #200 Sieve)

0.0 - 0.6 ft. Well-graded SAND with clay and gravel (SW-SC), tan, no plasticity, dry.

SS Bedrock.

Bottom of Hole at 0.6 ft.

Weather Notes: Sunny 90s

Inclination from Horiz.: Vertical

Groundwater Levels: Not Observed

Night Work:

Logged By: M. Kelly

Final By: M. Kelly

Symbol Depth Date

Drilling Method(s):

Boring Began: 8/8/2023

Boring Completed: 8/8/2023

Driller: Yeh & Associates, Inc.

Drill Rig: Hand Auger

Hammer: , ER: %

Hand Auger

Total Depth: 0.6 ft

Ground Elevation: 6980.0 ft

Coordinates: Lat: 37.1834206904 Long: -108.488268636

Location: Chapin Mesa along exterior walls of building 1.

Atterberg Limits

E le va tio n (f ee t)

PAGE

AASHTO

& USCS

Classifi-cations

Li qu id Li m it

P la st ic ity In de x

D ril lin g

M et ho d

Project Number: 222-342 Boring No.: YA-HA-1

S am pl e

T yp e/ D ep th

Project Name:

D ep th (f ee t)

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Field Notes and

Other Lab Tests

F in es C on te nt

B

O R

IN

G

L O

G

S

P T

C D

O T

S T

Y

LE

-3

M E

S A

V E

R D

E .G

P J

Y

E H

C O

LO

R

A D

O T

E M

P

LA

T E

.G D

T

Y E

H C

O

LO

R A

D O

L

IB

R A

R Y

.G

LB

/1

4/

Li th ol o gy Soil Samples

P en et ra tio n

R es is ta nc e

Blows per 6 in

Material Description

D ry

D en si ty

(p cf

M oi st ur e C on te nt

0.0 - 1.6 ft. Well-graded SAND with clay and

SS Bedrock.

Bottom of Hole at 1.6 ft.

Weather Notes: Sunny 90s

Inclination from Horiz.: Vertical

Groundwater Levels: Not Observed

Night Work:

Logged By: M. Kelly

Final By: M. Kelly

Symbol Depth Date

Drilling Method(s):

Boring Began: 8/8/2023

Boring Completed: 8/8/2023

Driller: Yeh & Associates, Inc.

Drill Rig: Hand Auger

Hammer: , ER: %

Hand Auger

Total Depth: 1.6 ft

Ground Elevation: 6980.0 ft

Coordinates: Lat: 37.1834471018 Long: -108.488464617

Location: Chapin Mesa along exterior walls of building 1.

Atterberg Limits

E le va tio n (f ee t)

PAGE

AASHTO

& USCS

Classifi-cations

Li qu id Li m it

P la st ic ity In de x

D ril lin g

M et ho d

Project Number: 222-342 Boring No.: YA-HA-1A

S am pl e

T yp e/ D ep th

Project Name:

D ep th (f ee t)

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Field Notes and

Other Lab Tests

F in es C on te nt

B

O R

IN

G

L O

G

S

P T

C D

O T

S T

Y

LE

-3

M E

S A

V E

R D

E .G

P J

Y

E H

C O

LO

R

A D

O T

E M

P

LA

T E

.G D

T

Y E

H C

O

LO

R A

D O

L

IB

R A

R Y

.G

LB

/1

4/

Li th ol o gy Soil Samples

P en et ra tio n

R es is ta nc e

Blows per 6 in

Material Description

D ry

D en si ty

(p cf

M oi st ur e C on te nt

0.0 - 3.3 ft. Well-graded SAND with clay and gravel (SW-SC), tan, no to low plasticity, dry.

SS Bedrock.

Bottom of Hole at 3.3 ft.

Weather Notes: Sunny 90s

Inclination from Horiz.: Vertical

Groundwater Levels: Not Observed

Night Work:

Logged By: M. Kelly

Final By: M. Kelly

Symbol Depth Date

Drilling Method(s):

Boring Began: 8/8/2023

Boring Completed: 8/8/2023

Driller: Yeh & Associates, Inc.

Drill Rig: Hand Auger

Hammer: , ER: %

Hand Auger

Total Depth: 3.3 ft

Ground Elevation: 6980.0 ft

Coordinates: Lat: 37.183562864 Long: -108.489500918

Location: Chapin Mesa along exterior walls of building 2.

Atterberg Limits

E le va tio n (f ee t)

PAGE

AASHTO

& USCS

Classifi-cations

Li qu id Li m it

P la st ic ity In de x

D ril lin g

M et ho d

Project Number: 222-342 Boring No.: YA-HA-2

S am pl e

T yp e/ D ep th

Project Name:

D ep th (f ee t)

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Field Notes and

Other Lab Tests

F in es C on te nt

B

O R

IN

G

L O

G

S

P T

C D

O T

S T

Y

LE

-3

M E

S A

V E

R D

E .G

P J

Y

E H

C O

LO

R

A D

O T

E M

P

LA

T E

.G D

T

Y E

H C

O

LO

R A

D O

L

IB

R A

R Y

.G

LB

/1

4/

Li th ol o gy Soil Samples

P en et ra tio n

R es is ta nc e

Blows per 6 in

Material Description

D ry

D en si ty

(p cf

M oi st ur e C on te nt

0.0 - 1.6 ft. Well-graded SAND with clay and gravel (SW-SC), tan, no to low plasticity, dry.

SS Bedrock.

Bottom of Hole at 1.6 ft.

Weather Notes: Sunny 90s

Inclination from Horiz.: Vertical

Groundwater Levels: Not Observed

Night Work:

Logged By: M. Kelly

Final By: M. Kelly

Symbol Depth Date

Drilling Method(s):

Boring Began: 8/8/2023

Boring Completed: 8/8/2023

Driller: Yeh & Associates, Inc.

Drill Rig: Hand Auger

Hammer: , ER: %

Hand Auger

Total Depth: 1.6 ft

Ground Elevation: 6980.0 ft

Coordinates: Lat: 37.1834657409 Long: -108.489550913

Location: Chapin Mesa along exterior walls of building 2.

Atterberg Limits

E le va tio n (f ee t)

PAGE

AASHTO

& USCS

Classifi-cations

Li qu id Li m it

P la st ic ity In de x

D ril lin g

M et ho d

Project Number: 222-342 Boring No.: YA-HA-2A

S am pl e

T yp e/ D ep th

Project Name:

D ep th (f ee t)

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Field Notes and

Other Lab Tests

F in es C on te nt

B

O R

IN

G

L O

G

S

P T

C D

O T

S T

Y

LE

-3

M E

S A

V E

R D

E .G

P J

Y

E H

C O

LO

R

A D

O T

E M

P

LA

T E

.G D

T

Y E

H C

O

LO

R A

D O

L

IB

R A

R Y

.G

LB

/1

4/

Li th ol o gy Soil Samples

P en et ra tio n

R es is ta nc e

Blows per 6 in

Material Description

D ry

D en si ty

(p cf

M oi st ur e C on te nt

0.5 ft - Refusal

0.0 - 0.5 ft. Clayey SAND with gravel (SC), brown and tan, low plasticity, dry.

Bottom of Hole at 0.5 ft.

Weather Notes: Sunny 90s

Inclination from Horiz.: Vertical

Groundwater Levels: Not Observed

Night Work:

Logged By: M. Kelly

Final By: M. Kelly

Symbol Depth Date

Drilling Method(s):

Boring Began: 8/8/2023

Boring Completed: 8/8/2023

Driller: Yeh & Associates, Inc.

Drill Rig: Hand Auger

Hammer: , ER: %

Hollow-Stem Auger

Total Depth: 0.5 ft

Ground Elevation: 6980.0 ft

Coordinates: Lat: 37.1839403323 Long: -108.489697088

Location: Chapin Mesa along exterior walls of building 3.

Atterberg Limits

E le va tio n (f ee t)

PAGE

AASHTO

& USCS

Classifi-cations

Li qu id Li m it

P la st ic ity In de x

D ril lin g

M et ho d

Project Number: 222-342 Boring No.: YA-HA-3

S am pl e

T yp e/ D ep th

Project Name:

D ep th (f ee t)

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Field Notes and

Other Lab Tests

F in es C on te nt

B

O R

IN

G

L O

G

S

P T

C D

O T

S T

Y

LE

-3

M E

S A

V E

R D

E .G

P J

Y

E H

C O

LO

R

A D

O T

E M

P

LA

T E

.G D

T

Y E

H C

O

LO

R A

D O

L

IB

R A

R Y

.G

LB

/1

4/

Li th ol o gy Soil Samples

P en et ra tio n

R es is ta nc e

Blows per 6 in

Material Description

D ry

D en si ty

(p cf

M oi st ur e C on te nt wood in sample

1.7 ft - Refusal

0.0 - 1.7 ft. Well-graded SAND with clay and gravel (SW-SC) (Fill), tan, no plasticity, dry, organics.

SS Bedrock.

Bottom of Hole at 1.7 ft.

Weather Notes: Sunny 90s

Inclination from Horiz.: Vertical

Groundwater Levels: Not Observed

Night Work:

Logged By: M. Kelly

Final By: M. Kelly

Symbol Depth Date

Drilling Method(s):

Boring Began: 8/8/2023

Boring Completed: 8/8/2023

Driller: Yeh & Associates, Inc.

Drill Rig: Hand Auger

Hammer: , ER: %

Hollow-Stem Auger

Total Depth: 1.7 ft

Ground Elevation: 6980.0 ft

Coordinates: Lat: 37.183903686 Long: -108.489494396

Location: Chapin Mesa along exterior walls of building 3.

Atterberg Limits

E le va tio n (f ee t)

PAGE

AASHTO

& USCS

Classifi-cations

Li qu id Li m it

P la st ic ity In de x

D ril lin g

M et ho d

Project Number: 222-342 Boring No.: YA-HA-3A

S am pl e

T yp e/ D ep th

Project Name:

D ep th (f ee t)

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Field Notes and

Other Lab Tests

F in es C on te nt

B

O R

IN

G

L O

G

S

P T

C D

O T

S T

Y

LE

-3

M E

S A

V E

R D

E .G

P J

Y

E H

C O

LO

R

A D

O T

E M

P

LA

T E

.G D

T

Y E

H C

O

LO

R A

D O

L

IB

R A

R Y

.G

LB

/1

4/

Li th ol o gy Soil Samples

P en et ra tio n

R es is ta nc e

Blows per 6 in

Material Description

D ry

D en si ty

(p cf

M oi st ur e C on te nt wood in sample

1.6 ft - Refusal

0.0 - 1.6 ft. Well-graded SAND with clay and gravel (SW-SC) (Fill), tan, no plasticity, dry, organics.

SS Bedrock.

Bottom of Hole at 1.6 ft.

Weather Notes: Sunny 90s

Inclination from Horiz.: Vertical

Groundwater Levels: Not Observed

Night Work:

Logged By: M. Kelly

Final By: M. Kelly

Symbol Depth Date

Drilling Method(s):

Boring Began: 8/8/2023

Boring Completed: 8/8/2023

Driller: Yeh & Associates, Inc.

Drill Rig: Hand Auger

Hammer: , ER: %

Hand Auger

Total Depth: 1.6 ft

Ground Elevation: 6980.0 ft

Coordinates: Lat: 37.1838525546 Long: 108.489604767

Location: Chapin Mesa along exterior walls of building 3.

Atterberg Limits

E le va tio n (f ee t)

PAGE

AASHTO

& USCS

Classifi-cations

Li qu id Li m it

P la st ic ity In de x

D ril lin g

M et ho d

Project Number: 222-342 Boring No.: YA-HA-3B

S am pl e

T yp e/ D ep th

Project Name:

D ep th (f ee t)

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Field Notes and

Other Lab Tests

F in es C on te nt

B

O R

IN

G

L O

G

S

P T

C D

O T

S T

Y

LE

-3

M E

S A

V E

R D

E .G

P J

Y

E H

C O

LO

R

A D

O T

E M

P

LA

T E

.G D

T

Y E

H C

O

LO

R A

D O

L

IB

R A

R Y

.G

LB

/1

4/

Li th ol o gy Soil Samples

P en et ra tio n

R es is ta nc e

Blows per 6 in

Material Description

D ry

D en si ty

(p cf

M oi st ur e C on te nt

0.8 ft - Refusal

0.0 - 0.8 ft. Well-graded SAND with clay and gravel (SW-SC) (Fill), brown, no plasticity, dry, organics.

Bottom of Hole at 0.8 ft.

Weather Notes: Sunny 90s

Inclination from Horiz.: Vertical

Groundwater Levels: Not Observed

Night Work:

Logged By: M. Kelly

Final By: M. Kelly

Symbol Depth Date

Drilling Method(s):

Boring Began: 8/8/2023

Boring Completed: 8/8/2023

Driller: Yeh & Associates, Inc.

Drill Rig: Hand Auger

Hammer: , ER: %

Hand Auger

Total Depth: 0.8 ft

Ground Elevation: 6980.0 ft

Coordinates: Lat: 37.1838884717 Long: -108.489981048

Location: Chapin Mesa along exterior walls of building 4.

Atterberg Limits

E le va tio n (f ee t)

PAGE

AASHTO

& USCS

Classifi-cations

Li qu id Li m it

P la st ic ity In de x

D ril lin g

M et ho d

Project Number: 222-342 Boring No.: YA-HA-4

S am pl e

T yp e/ D ep th

Project Name:

D ep th (f ee t)

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Field Notes and

Other Lab Tests

F in es C on te nt

B

O R

IN

G

L O

G

S

P T

C D

O T

S T

Y

LE

-3

M E

S A

V E

R D

E .G

P J

Y

E H

C O

LO

R

A D

O T

E M

P

LA

T E

.G D

T

Y E

H C

O

LO

R A

D O

L

IB

R A

R Y

.G

LB

/1

4/

Li th ol o gy Soil Samples

P en et ra tio n

R es is ta nc e

Blows per 6 in

Material Description

D ry

D en si ty

(p cf

M oi st ur e C on te nt gravel (SW-SC), brown, no plasticity, dry.

Bottom of Hole at 0.8 ft.

Weather Notes: Sunny 90s

Inclination from Horiz.: Vertical

Groundwater Levels: Not Observed

Night Work:

Logged By: M. Kelly

Final By: M. Kelly

Symbol Depth Date

Drilling Method(s):

Boring Began: 8/8/2023

Boring Completed: 8/8/2023

Driller: Yeh & Associates, Inc.

Drill Rig: Hand Auger

Hammer: , ER: %

Hand Auger

Total Depth: 0.8 ft

Ground Elevation: 6980.0 ft

Coordinates: Lat: 37.1838500064 Long: -108.489826869

Location: Chapin Mesa along exterior walls of building 4.

Atterberg Limits

E le va tio n (f ee t)

PAGE

AASHTO

& USCS

Classifi-cations

Li qu id Li m it

P la st ic ity In de x

D ril lin g

M et ho d

Project Number: 222-342 Boring No.: YA-HA-4A

S am pl e

T yp e/ D ep th

Project Name:

D ep th (f ee t)

ES NPS MEVE Chapin Mesa Historic Structure Rehab

Field Notes and

Other Lab Tests

F in es C on te nt

B

O R

IN

G

L O

G

S

P T

C D

O T

S T

Y

LE

-3

M E

S A

V E

R D

E .G

P J

Y

E H

C O

LO

R

A D

O T

E M

P

LA

T E

.G D

T

Y E

H C

O

LO

R A

D O

L

IB

R A

R Y

.G

LB

/1

4/

Li th ol o gy Soil Samples

P en…