Airway_Avenue_Geotech_Eval_Rpt_3-22-19.pdf

Geotechnical Evaluation Airway Avenue Drainage Channel

Diamond Joe Road to Airway Avenue

Kingman, Arizona

Dibble Engineering

7878 North 16 th

Street, Suite 300 | Phoenix, Arizona 85020

March 22, 2019 | Project No. 605987001

Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness

Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS

3202 East Harbour Drive | Phoenix, Arizona 85034 | p. 602.243.1600 | www.ninyoandmoore.com

March 22, 2019 Project No. 605987001

Mr. Paul Balch, PE Dibble Engineering 7878 North 16th Street, Suite 300 Phoenix, Arizona 85020

Subject: Geotechnical Evaluation Airway Avenue Drainage Channel Diamond Joe Road to Airway Avenue Kingman, Arizona

Dear Mr. Balch:

In accordance with our proposal dated November 26, 2018, and your authorization, Ninyo & Moore has performed a geotechnical evaluation for the above-referenced site. The attached report presents our methodology, findings, conclusions, and recommendations regarding the geotechnical conditions at the project site.

Ninyo & Moore appreciates the opportunity to be of service to you on this project.

Respectfully submitted, NINYO & MOORE

Dylan C. Walker, EIT Senior Staff Engineer

Jeffrey Rodgers, PE, PG Principal Engineer

DCW/JSR/tlp

Distribution: (1) Addressee (via e-mail)

3/2 2/1 http://www.ninyoandmoore.com/

Ninyo & Moore | Diamond Joe Road to Airway Avenue, Kingman, Arizona | 605987001 R | March 22, 2019 i

CONTENTS

1 INTRODUCTION 1

2 SCOPE OF SERVICES 1

3 SITE DESCRIPTION 2

4 AERIAL PHOTOGRAPH REVIEW 2

5 PROPOSED CONSTRUCTION 3

6 FIELD EXPLORATION AND LABORATORY TESTING 3

6.1 Laboratory Testing 3

6.2 Infiltration (Percolation) Test 4

7 GEOLOGY AND SUBSURFACE CONDITIONS 4

7.1 Geologic Setting 4

7.2 Subsurface Conditions 5

7.2.1 Fill 5

7.2.2 Alluvium 5

7.2.3 Groundwater 5

8 GEOLOGIC HAZARDS 5

8.1 Faulting and Seismicity 6

9 GEOTECHNICAL CONSIDERATIONS 6

10 RECOMMENDATIONS 7

10.1 Earthwork 7

10.1.1 Site Preparation 8

10.1.2 Wet Weather Conditions 8

10.1.3 Excavations and Temporary Slope Stability 8

10.1.4 Retention Basin and Channel Slope Recommendations 9

10.1.5 Fill Materials 10

10.1.6 Re-use of On-Site Soils 10

10.1.7 Subgrade Improvement 10

10.1.8 Fill Placement and Compaction 11

10.1.9 Site Drainage 11

10.2 Foundations for Culvert Headwalls 12

10.2.1 Spread Footings 12

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10.3 Head Walls 12

10.3.1 Active Conditions 13

10.3.2 At Rest Conditions 13

10.3.3 Passive Conditions 13

10.4 Pavements 14

10.4.1 Design R-value 14

10.4.2 Traffic Volumes and Truck Factor Growth Rates 14

10.4.3 Resilient Modulus 14

10.4.4 Drainage Coefficient 14

10.4.5 Serviceability 15

10.4.6 Standard Deviation and Level of Reliability 15

10.4.7 Structural Number Summary 15

10.4.8 Recommendations 15

10.5 Corrosion 15

10.6 Concrete 16

10.7 Pre-Construction Conference 17

10.8 Construction Observation and Testing 17

11 LIMITATIONS 17

12 REFERENCES 19

TABLES

1 – Summary of Aerial Photograph Review 2

2 – Boring Summary 3

3 – Compaction Recommendations 11

4 – ACI Requirements for Concrete Exposed to Sulfate-Containing Soil 16

FIGURES

1 – Site Location

2 – Boring Locations

APPENDICES

A – Boring Logs

B – Laboratory Testing

C – Percolation Test Results

Ninyo & Moore | Diamond Joe Road to Airway Avenue, Kingman, Arizona | 605987001 R | March 22, 2019 1

1 INTRODUCTION

In accordance with our proposal dated November 26, 2018, and your authorization, we have performed a geotechnical evaluation for the proposed Airway Avenue Drainage Channel Project to be located between Diamond Joe Road and Airway Avenue in Kingman, Arizona. The purpose of our evaluation was to assess the subsurface conditions at the project site in order to provide geotechnical recommendations for design and construction. This report presents the results of our evaluation, and our geotechnical considerations and recommendations regarding the proposed construction.

2 SCOPE OF SERVICES

The scope of our services for this project generally included:

Reviewing readily available geotechnical data, aerial photographs, and published geologic literature, including maps and reports pertaining to the project site and vicinity.

Conducting a geologic reconnaissance of the site.

Marking out the boring locations at the project site, securing permission to drill, and notifying Arizona 811 of the boring locations prior to drilling.

Drilling, logging, and sampling five exploratory borings to depths ranging from approximately 9 to 14 feet below ground surface (bgs). The boring logs are presented in Appendix A.

Hand sampling one exploratory boring to a depth of 2 feet bgs. Laboratory Results are presented in Appendix B.

Collecting soil samples in the borings at approximately 2.5 and 5.0-foot intervals using ASTM International (ASTM) Methods D1586 (standard penetration test with split-spoon barrel sampling of soils) and D3550 (ring-lined barrel sampling of soils) for laboratory testing and analysis.

Performing laboratory tests on selected samples obtained from the borings to evaluate in-situ moisture content and dry density, particle-size gradation, Atterberg limits, and corrosivity characteristics (including pH, minimum electrical resistivity, and soluble sulfate and chloride contents). The in-situ moisture content and dry density results are presented on the boring logs in Appendix A. The remainder of the laboratory test results are presented in Appendix B.

Performing field infiltration tests (percolation test) at two locations near the northeast and southwest portions of the planned retention basin. The results of the field percolation tests are presented in Appendix C.

Preparing this report presenting our findings, conclusions, and recommendations regarding the design and construction of the project.

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Our scope of services did not include environmental consulting services such as hazardous waste sampling or analytical testing at the site. A detailed scope of services and estimated fee for such services can be provided upon request.

3 SITE DESCRIPTION

The project site is located just south of the White Cliffs Middle School between Airway Avenue and Diamond Joe Road in Kingman, Arizona (Figure 1). At the time of our evaluation, the site consisted of an existing drainage channel which flowed from the southeast to the northwest parallel with residential housing and continued across Airway Avenue towards White Cliffs

Middle School. The surrounding topography comprised of rugged mountains, hills, and scattered drainages. The site was bound by residential property to the west, undeveloped desert land to the east, White Cliffs Middle School to the north, and undeveloped desert land to the south.

According to the Rattlesnake Hill, Arizona 7.5-Minute United States Geological Survey

Topographic Quadrangle Map (2018), the site transitions from an elevation of 3,555 feet relative to mean sea level (MSL) near the southeast portion of the site to an elevation of 3,494 feet relative to MSL near the northwest portion of the site, with a topographic relief of approximately

61 feet along the alignment. Based on information from this topographic quadrangle map, the ground surface at the site vicinity generally slopes from the southeast to the northwest.

4 AERIAL PHOTOGRAPH REVIEW

Aerial photographs dated 1990 through 2018 from the Mohave County website and Google

Earth repository were reviewed for this project. A summary of the observations noted for each aerial photograph is presented in Table 1:

Table 1 – Summary of Aerial Photograph Review

Photograph Date(s)

Site Adjacent Properties

1990, 1997, 2003, 2005, 2006, 2007

Scattered washes and partially developed drainage channel.

North: Retention basin and undeveloped desert land.

South: Undeveloped desert land and Interstate 40.

East: Undeveloped desert land.

West:

Undeveloped desert land and scattered residential housing.

2010, 2011, 2013, 2015, 2017, 2018

Developed drainage channel.

North:

White Cliffs Middle School and undeveloped desert land.

South: Residential housing and Interstate 40.

East: Undeveloped desert land.

West:

Undeveloped desert land and scattered residential housing.

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5 PROPOSED CONSTRUCTION

The project includes the design and construction of a new drainage channel, retention basin, and the re-alignment of Airway Avenue. We understand the new retention basin is planned to be located adjacent to the eastern side of the drainage channel, approximately 500 feet south of

Airway Avenue. The new retention basin is planned to be about 2 acres and have a depth on the order of 4 to 5 feet deep. The new channel is planned to be on the order of 4 ½ feet deep with side slopes at a 3:1 (Horizontal:Vertical) slope. As a part of the drainage improvements, new pipe or box culverts are also planned at the crossing of Airway Avenue which will be re-aligned east of Prospector Street to the north, adjacent to White Cliffs Middle School.

Grading and drainage plans for the roadway prism were also not available at the time of our report. Based on our site observations, we understand that the new roadway construction will remain at or near its current grade. In addition, we assume positive drainage will be established within the roadway during and after construction at the site.

6 FIELD EXPLORATION AND LABORATORY TESTING

On February 27, 2019, Ninyo & Moore conducted a subsurface exploration at the site in order to evaluate the subsurface conditions and to collect soil samples for laboratory testing. Our evaluation consisted of drilling, logging, and sampling of five small-diameter borings using a

CME-75 truck-mounted drill rig equipped with hollow-stem augers. The borings, denoted as

B-1 through B-5, extended to depths of approximately 9 to 14 feet bgs (Figure 2). A hand sample, denoted as HS-1 was collected at the bottom of the channel near Boring B-1 to run laboratory testing for scour analysis. Bulk and relatively undisturbed soil samples were collected at selected intervals. Descriptions of the soils encountered are presented in the boring logs in

Appendix A. Table 2 presents the purpose and depth of each boring at the site.

Table 2 – Boring Summary

Purpose Borings Approximate Depth (ft)

Pavement and Box Culverts B-1, HS-1 2 to 10

Drainage Channel and Retention Basins

B-2 through B-5 9 to 14

6.1 Laboratory Testing

The soil samples collected from our drilling activities were transported to the Ninyo & Moore laboratory in Phoenix, Arizona. In addition, Ninyo & Moore performed laboratory tests on selected samples obtained from the borings to evaluate the in-situ moisture content and dry

Ninyo & Moore | Diamond Joe Road to Airway Avenue, Kingman, Arizona | 605987001 R | March 22, 2019 4 density, particle-size gradation, Atterberg limits, and corrosivity characteristics (including pH, minimum electrical resistivity, and soluble sulfate and chloride contents).

The in-situ moisture content and dry density results are presented on the boring logs in

Appendix A. A description of the laboratory testing as well as the remainder of the laboratory test results are presented in Appendix B.

6.2 Infiltration (Percolation) Test

In order to assist in the evaluation of the infiltration rates at the site, Ninyo & Moore performed two field infiltration (percolation) tests denoted as PT-1 and PT-2 (Figure 2). The infiltration test procedure included clearing of the surface material in order to embed a 10-inch-outer-diameter polyvinyl-chloride (PVC) casing into the ground approximately 4 feet. The PVC casing was filled with water in order to pre-wet the soil. The test continued after the pre-wetting period by refilling the casing and measuring the drop in water level as a function of time until approximately steady-state conditions were achieved. The results of this test are presented in Appendix C and should be viewed as approximate as they are based on the conditions at the location at the time of our test.

7 GEOLOGY AND SUBSURFACE CONDITIONS

The geology and subsurface conditions at the site are described in the following sections.

7.1 Geologic Setting

The project site is located in what is known as the Transition Zone physiographic province, an approximately 50-mile wide mountain belt that traverses northwest-southeast through central

Arizona. This province is the physiographic transition between the Colorado Plateau province and Basin and Range province in Arizona. The province is characterized by the presence of

Proterozoic (1.7 billion years) granitic and metamorphic rocks that were exposed as the sedimentary Paleozoic (510 million years) and Mesozoic (245 million years) rocks were eroded away. High-angle normal faults and block faulting occurred during the Mid-Tertiary which also coincided with an increase in volcanic activity during this time (Kamilli and Richard, 1998).

The surficial geology of the site is described as Holocene-age (less than 10,000 years) alluvial fan and terrace deposits (Ferguson and Cook, 2015). The United States Department of

Agriculture Web Soil Survey described the site as generally consisting of Jagerson very gravelly

Loam. Jagerson Loam generally consists of silty sands and lean clays typically suitable for roadway subgrades.

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7.2 Subsurface Conditions

Our knowledge of the subsurface conditions at the project site is based on the results of our exploratory borings and our understanding of the general geology of the area. The boring logs contain our field test results, as well as our interpretation of the conditions likely to exist between actual samples retrieved. Therefore, the boring logs contain both factual and interpretive information. Lines delineating subsurface strata on the boring logs are intended to group soils having similar engineering properties and characteristics. They should be considered approximate, as the actual transition between soil types may be gradual. Detailed stratigraphic information as well as a key to the soil symbols and terms used on the boring logs are provided in Appendix A.

7.2.1 Fill

Undocumented fill soils were encountered at the ground surface in Boring

B-4 and extended to a depth of approximately 3 feet. The fill generally consisted of medium dense silty, clayey sands (SC-SM) in our boring.

7.2.2 Alluvium

Native alluvial soil was encountered beneath the fill soils described above and at the surface of the remaining borings, and extended to the boring termination depths. In our borings, the alluvium generally consisted of medium dense to dense silty sands (SM), clayey sands (SC), and hard to very stiff sandy lean clay (CL). Varying quantities of gravel and scattered caliche nodules with moderate degrees of cementation were also observed in our borings.

7.2.3 Groundwater

Groundwater was not encountered in our borings. Based on well data from the

Arizona Department of Water Resources, groundwater at the site is estimated to be at an approximate elevation of 2,715 feet MSL, which corresponds to a depth of approximately

779 feet bgs at the northern limits and 840 feet bgs at the southern limits of the project alignment. Groundwater levels can fluctuate due to seasonal variations, irrigation, groundwater withdrawal or injection, and other factors. In general, groundwater is not anticipated to be a constraint to the construction of the project.

8 GEOLOGIC HAZARDS

The following sections describe regional geologic hazards.

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8.1 Faulting and Seismicity

The site lies within the Sonoran zone, which is a relatively stable tectonic region located in southwestern Arizona, southeastern California, southern Nevada, and northern Mexico

(Euge et al., 1992). This zone is characterized by sparse seismicity and few Quaternary faults.

Based on our field observations, review of pertinent geologic data, and analysis of aerial photographs, Quaternary faults are not located on or adjacent to the property.

The closest documented Quaternary faults to the site is the Hurricane Fault Zone, located approximately 37 miles to the northeast of the site and the Needles Graben Fault Zone, located approximately 36 miles to the southwest (Pearthree, 1998).

The Hurricane Fault Zone is an approximate 150-mile long series of normal faults that strike to the northeast and dip to the northwest. The latest movement has been documented to be around 1.6 million years ago in the early Pleistocene. The slip-rate category for this fault zone is less than 0.2 millimeters per year (Pearthree, 1998).

The Needles Graben faults are situated along the western side of the Black Mountains. The faults are a series of north-northwest striking normal faults that dip to the northeast-southwest.

Four meters of displacement has been measured within the lower to middle Pleistocene

(1.8 million years to 750,000 years) units, and 2 meters of displacement in the upper

Pleistocene (750,000 years to 10,000 years) units. Holocene (<10,000 years) age deposits are not displaced. The most recent movement documented along this fault was less than approximately 130,000 years ago during the early Pleistocene epoch. The slip-rate category of this fault is less than 0.2 millimeters per year (Pearthree, 1998).

Seismic design considerations are provided in Section 10.2.

9 GEOTECHNICAL CONSIDERATIONS

Based on the results of our subsurface evaluation, laboratory testing, and data analysis, it is our opinion that the proposed construction is feasible from a geotechnical standpoint, provided that the recommendations of this report are incorporated into the design and construction of the proposed project, as appropriate. Geotechnical considerations include the following:

Due to the widely spaced nature of our borings, soil conditions that differ from what was encountered in our borings may be encountered during construction.

Earthwork contractors should be made aware of the moisture sensitivity of the near surface clayey and silty soils and potential compaction difficulties.

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The near-surface on-site materials are considered generally excavatable with heavy-duty earthmoving equipment. Very dense sands and moderate levels of cementation were encountered in our borings at various depths, which could be more difficult to excavate during construction.

Imported soils and soils generated from on-site excavation activities that exhibit relatively low plasticity and low organic contents can generally be used as engineered fill. On the basis of our limited evaluation, many of the on-site soils are not considered to be suitable for re-use as engineered fill.

The head walls may be supported on shallow spread footings proportioned for moderate bearing pressures on a zone of engineered fill.

Groundwater was not observed in our borings. The static groundwater table is anticipated to be approximately 779 feet bgs at the northern limits and 840 feet bgs at the southern limits of the project alignment.

No known or reported geologic hazards are present underlying, or immediately adjacent to, the site.

Corrosivity test results indicate that subgrade soils at the site are generally non-corrosive to ferrous metals, and the sulfate content of the soils present a negligible sulfate exposure to concrete.

10 RECOMMENDATIONS

The following sections present our geotechnical recommendations and were developed based on our understanding of the proposed construction (Section 5), the observed subsurface conditions (Section 7.2), and our experience. If the proposed construction is changed from that discussed herein or subsurface conditions other than those shown on the boring logs

(Appendix A) are observed at the time of construction, Ninyo & Moore should be retained to conduct a review of the new information and to evaluate the need for additional recommendations.

10.1 Earthwork

In general, the recommendations and guidelines outlined in the Maricopa Association of

Governments (MAG) Standard Specifications and Details and/or any City of Kingman supplement should be used unless recommended differently herein. If the proposed construction is changed from that discussed in this report, Ninyo & Moore should be contacted for additional recommendations. Due to the relatively widely spaced nature of our borings, soil conditions not observed in our borings may be encountered during construction.

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10.1.1 Site Preparation

Prior to placing any fill, pavement, or flatwork, the following guidelines should be followed:

Obstructions that extend below finish grade, if any, should be removed and the resulting holes filled with compacted soil.

After stripping, clearing, grubbing, and root raking is performed and prior to placement of any fill soils, the exposed subgrade should be evaluated by proof-rolling. Any soft or weak areas observed during the proof-rolling process should be removed and replaced with compacted material as outlined in Section 10.1.8.

Proof-rolling should be accomplished with a pneumatic-tired roller, a loaded dump truck, or similar equipment weighing approximately 20 tons and observed by the Geotechnical Engineer-of-Record, or the Engineer’s designated representative.

Due to the clayey and silty nature of the surficial soils at some locations along the alignment, traffic of heavy equipment (including heavy compaction equipment) may create pumping and general deterioration of shallow soils. Therefore, some construction difficulties should be anticipated, especially during periods when these soils are wet.

10.1.2 Wet Weather Conditions

Earthwork contractors should be made aware of the moisture sensitivity of the near surface clayey and silty soils and potential compaction difficulties. If construction is undertaken during wet weather conditions, the surficial soils may become saturated, soft, and unworkable. Therefore, we recommend that consideration be given to construction during the dryer months and positive drainage be established and maintained during construction.

10.1.3 Excavations and Temporary Slope Stability

Our evaluation of the excavation characteristics of the on-site materials is based on the results of our exploratory boring, site observations, and experience with similar materials.

Excavation of the materials can generally be accomplished with heavy-duty earthmoving equipment. However; scattered caliche filaments and nodules as well as moderately cemented soils were encountered in our borings and may be more difficult to excavate and/or slow the rate of excavation depending on the degree of cementation encountered during construction.

The contractor should provide safely sloped excavations or an adequately constructed and braced shoring system, in compliance with Occupational Safety and Health Administration

(OSHA) regulations for employees working in an excavation that may expose employees to the danger of moving ground. If material is stored or equipment is operated near an

Ninyo & Moore | Diamond Joe Road to Airway Avenue, Kingman, Arizona | 605987001 R | March 22, 2019 9 excavation, stronger shoring should be used to resist the extra pressure due to superimposed loads.

The contractor should provide safely sloped excavations or an adequately constructed and braced shoring system in compliance with OSHA Regulations for employees working in an excavation that may expose them to the danger of moving ground. Based on the soil conditions at the site, we recommend that OSHA Soil “Type C” classification be used for excavations at the site. This corresponds to temporary slopes of 1.5:1 (horizontal: vertical).

This side slope is for excavations that are less than 20 feet deep. If material is stored or equipment is operated near an excavation, stronger shoring should be used to resist the extra pressure due to superimposed loads.

If the proposed construction extends deeper than the extent of our test boring in any part of this project, Ninyo & Moore should be contacted for additional consultation and possible further evaluation of the subsurface materials.

10.1.4 Retention Basin and Channel Slope Recommendations

A detailed slope stability analysis was beyond the scope of this study. If stability parameters are needed, our office should be contacted. Based on our experience with similar soil conditions within this geologic region, we anticipate the side slopes of the basins should remain stable as long as:

3:1 (horizontal to vertical) slopes or flatter are used for slopes less than 5 feet in height

The condition of side slopes (erosion and/or surface sloughing) are evaluated and repaired as part of routine maintenance procedures.

As with any basin construction, exposed cut slopes may need periodic maintenance due to sloughing and erosion. To reduce the potential for erosion, we recommend erosion control measures be placed on the slopes. The establishment of erosion control measures is beneficial for long-term aesthetics, reduces erosion by slowing runoff velocities, and protects soil from raindrop impact.

Based on the results of our field infiltration rates (Appendix C), the factored infiltration rates ranged from approximately 1 to 2 inches per hour.

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10.1.5 Fill Materials

On-site and imported soils that exhibit relatively low plasticity indices are generally suitable for re-use as engineered fill. Relatively low plasticity indices, as evaluated by ASTM

D4318, are defined as a plasticity index (PI) of 15 or less for this project.

In addition, suitable fill should not include construction debris, organic material, or other non-soil fill materials. Clay lumps and rock particles should not be larger than 4 inches in dimension. Unsuitable fill material should be disposed of off-site or in non-structural areas.

Imported fill, if used, should consist of soils with a relatively low PI (15 or less). Import material in contact with ferrous metals should preferably have low corrosion potential

(minimum resistivity more than 2,000 ohm-cm, chloride content less than 25 parts per million [ppm]). In lieu of this, corrosion protection techniques (e.g., cathodic protection, pipe wrapping, etc.) can be implemented. A corrosion specialist should be consulted for recommendations of an appropriate corrosion protection technique. Imported material in contact with concrete should have a soluble sulfate content of less than 0.1 percent. The geotechnical consultant should evaluate such materials and details of their placement prior to importation.

10.1.6 Re-use of On-Site Soils

The Atterberg limits tests performed on soil samples obtained from our borings resulted in

PI values ranging between 0 (non-plastic) and 23. Based on our test results, many of the on-site soils are generally considered not suitable for re-use as engineered fill for this project; however, may be used in non-structural areas (e.g., landscaping). In addition, Atterberg limits tests performed on soil samples from B-5, which is located within the footprint of the proposed retention basin, resulted in PI values between 8 and 11. Based on these test results, many of the onsite soils located within the retention basin footprint are considered suitable for re-use as engineered fill. Additional field sampling and laboratory testing should be conducted by the contractor during construction to better screen for any unsuitable materials.

10.1.7 Subgrade Improvement

Based on our review of the background documents and the results of our exploration, alluvial soils with varying relative densities and consistencies were encountered along the proposed roadway and culvert alignments. We recommend that the upper 12 inches of soils below new pavements, culverts, and culvert headwall foundations be improved by overexcavation (beneath new Aggregate Base [AB] layer where appropriate) and

Ninyo & Moore | Diamond Joe Road to Airway Avenue, Kingman, Arizona | 605987001 R | March 22, 2019 11 recompacted as noted in Section 10.1.8. The overexcavation zone should extend laterally

12 inches beyond the pavement, flatwork, and culvert footprints. Once the overexcavation is finished and the underlying soils are exposed, further evaluation should be made by the on-site geotechnical representative. Based on this evaluation, additional remediation may be needed. This could include scarification of the exposed surface. This additional remediation, if needed, should be addressed by the geotechnical consultant during the earthwork operations.

10.1.8 Fill Placement and Compaction

Fill soils should be moisture-conditioned within the moisture range shown below in Table 3 and mechanically compacted to the percent compaction shown. Fill should generally be placed in 8-inch-thick loose lifts such that each lift is firm and non-yielding under the weight of construction equipment.

Table 3 – Compaction Recommendations

Description Percent Compaction per

ASTM D698

Moisture Content

AB 100 percent

±2 percent of optimum Roadway Subgrade below

AB

95 percent

Head Wall Foundations and culverts

95 percent ±2 percent of optimum

Notes:

*Based on MAG guidelines, the definition of “granular backfill” materials is material in which the sum of the PI and the percent of material passing a No. 200 sieve does not exceed 23.

An earthwork (shrinkage) factor of 10 to 20 percent is estimated. This shrinkage factor range represents an average of the material tested and assumes that materials excavated from the site will be placed as fill. Potential bidders should consider this in preparing estimates and should review the available data to make their own conclusions regarding excavation conditions.

10.1.9 Site Drainage

The long-term performance of the foundation system depends, in part, on maintaining positive surface drainage during the life of the pavement. Ponding of water should not be allowed on pavements. Finished grade within 5 feet of the roadway should be adjusted to slope away from the structure at a slope of 2 percent, or more.

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10.2 Foundations for Culvert Headwalls

Based on the results of the field and laboratory evaluations, it is our opinion that the proposed culvert system, including headwalls, be supported on shallow foundations bearing on overexcavated and recompacted material as outlined in this report. Recommendations for these foundation systems are presented in the following sections of this report.

10.2.1 Spread Footings

Spread or continuous footings, if utilized, should be supported at a depth of 18 inches or more below the adjacent finished grade. The footings should be supported on engineered fill, as described in Section 10.1.8. Continuous footings should have a width of 18 or more inches, and isolated spread footings should have a width of 24 or more inches. Spread or continuous footings should be reinforced in accordance with the recommendations of the structural engineer.

Based on the available soil boring information, spread footings supported on engineered fill may be designed using a net allowable bearing capacity of 1,500 pounds per square foot

(psf) for static conditions. Total and differential settlement of up to about 1 inch and ½ inch respectively, may occur.

Foundations bearing on moisture-conditioned, compacted engineered fill that are subject to lateral loadings may be designed using an ultimate coefficient of friction of 0.40

(total frictional resistance equivalent to the coefficient of friction multiplied by the dead load).

A passive resistance value of 300 psf per foot of depth can be used. The lateral resistance can be taken as the sum of the frictional resistance and passive resistance, provided that the passive resistance does not exceed one-half of the total allowable resistance. The passive resistance may be increased by one-third when considering loads of short duration such as wind or seismic forces. The foundations should preferably be proportioned such that the resultant force from lateral loadings falls within the kern (i.e., middle one-third).

10.3 Head Walls

Head walls should be supported on shallow spread footings as described in Section 10.2.

Drainage should consist of free-draining granular material and could be accompanied by weepholes through the wall or corrugated, perforated pipe placed parallel to the wall or abutment bottom, wrapped in a filter fabric, and surrounded by 6 inches or more of granular filter material (e.g., pea gravel). In lieu of the wrapped open-graded gravel, a geocomposite drainage mat attached to the wall and discharging to a drain pipe or weepholes may be considered.

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10.3.1 Active Conditions

Active earth pressure occurs when the wall moves away from the soils and the soil mass stretches horizontally, sufficient to mobilize its shear strength, and a condition of plastic equilibrium is reached. For a drained granular backfill, an equivalent fluid active earth pressure of 37 psf per foot (psf/ft) of wall height should be used for design of cantilevered, yielding walls. For undrained granular backfill, an equivalent fluid active earth pressure of

80 psf/ft of wall height should be used for design. An outward lateral movement of about

0.001H (where H is the height of the wall) at the top of the wall is generally needed to mobilize the active earth pressure conditions.

Unrestrained retaining walls should also be designed to resist a horizontal earth pressure of

0.31q. The value for “q” represents the vertical surcharge pressure induced by adjacent light loads, slab, or traffic loads plus any adjacent footing loads.

10.3.2 At Rest Conditions

A soil mass that is neither stretched nor compressed is said to be in an at-rest state. If the wall is rigidly restrained, so that it does not rotate sufficiently to reach the active earth pressure condition, at-rest earth pressure condition will exist. An equivalent fluid at-rest earth pressure of 56 psf/ft should be used for the drained condition. An equivalent fluid at-rest pressure of 89 psf/ft should be used for the undrained condition. Restrained retaining walls should also be designed to resist a horizontal earth pressure of 0.47q. The value for

“q” represents the vertical surcharge pressure induced by adjacent light loads, slab, or traffic loads plus any adjacent footing loads.

10.3.3 Passive Conditions

Passive earth pressure occurs when the wall or foundation moves into the soil and the soil mass is compressed horizontally, mobilizing its shear strength. For below-grade portions of the walls with granular backfill (derived from on-site soils) in front of the toe of the wall, an equivalent fluid passive earth pressure of 300 psf/ft can be used. For undrained conditions, an equivalent fluid passive pressure of 250 psf/ft can be used. These values assume that the ground is horizontal for a distance of 10 feet or more in front of the wall or three times the height generating the passive pressure, whichever is more. We recommend that the upper 12 inches of soil not protected by pavement or a concrete slab, or any soil subject to possible future scour or excavation, be neglected when calculating passive resistance.

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10.4 Pavements

The following sections provide our recommendations for the pavement design. The design service life for the AC pavement is estimated to be on the order of 20 years, with regular maintenance.

10.4.1 Design R-value

Correlated R-values were estimated using the procedure described in the

Arizona Department of Transportation (ADOT) Preliminary Engineering and Design Manual

(PE&DM). Based on the procedure outlined in the PE&DM, R values were correlated from each sample tested within the project footprint. On average, R values correlated from samples north of Airway Avenue were estimated to be approximately 20. R values correlated from samples south of Airway Avenue were estimate to be between 28 and 40.

For design purposes, we estimated an R-value of 30. We also recommend that imported soils placed within 3 feet of finished roadway subgrade (if needed) demonstrate a construction control R-value of 30 or more.

10.4.2 Traffic Volumes and Truck Factor Growth Rates

The Average Daily Traffic (ADT) on the Airway Avenue alignment was estimated to be on the order of 3,300 vehicles per day based on the Rancho Santa Fe Traffic Interchange of

Access Addendum provided by Dibble Engineering. Information provided also stated that

Airway Avenue will be classified as an arterial roadway. Additional traffic information assumed included 5 percent heavy trucks, a directional distribution of 50 percent, and a

2 percent growth over the design life of 20 years. Based on these assumptions, and using the AASHTO procedure for pavement design, the one-way total flexible pavement equivalent single axle load was estimated to be 1,100,000.

10.4.3 Resilient Modulus

A design R-value of 30 was utilized in our analysis of new pavement sections. Based on an

R-value of 30 and a seasonal variation factor of 1.7 taken from Figure 202.02-1 in the

PE&DM, a resilient modulus of 13,514 psi was calculated.

10.4.4 Drainage Coefficient

A drainage coefficient of 0.92 was obtained from Table 202.02-7 in the PE&DM, based on a seasonal variation factor of 1.7 and fair drainage conditions.

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10.4.5 Serviceability

An initial serviceability of 4.1 and a terminal serviceability of 2.6 were used for the design of mainline pavements. The resulting serviceability index loss is 1.5.

10.4.6 Standard Deviation and Level of Reliability

A standard deviation of 0.45 was used for the design of flexible pavements in accordance with current ADOT policy. Based on Table 202.02-01 for roadways with an ADT between

2,001 and 10,000, a level of reliability of 90 percent was utilized for the design.

10.4.7 Structural Number Summary

In accordance with the procedure for flexible pavement design noted in the PE&DM, and using the above-mentioned parameters, the calculated the structural number for the AC roadway section is 2.86.

10.4.8 Recommendations

A pavement thickness of 4 inches of AC over 9 inches of AB course is recommended for this project. We recommend that the AB material conform to the gradation provided in MAG.

10.5 Corrosion

The corrosion potential of the on-site materials was tested to evaluate its potential effect on the foundations and structures. Our corrosion evaluation of the on-site soils is based on the results of our field and laboratory testing done for this project. A corrosion specialist should perform their own analysis.

Laboratory testing consisted of pH, minimum electrical resistivity, and chloride and soluble sulfate contents. The pH and minimum electrical resistivity tests were performed in general accordance with Arizona Test 236c, while sulfate and chloride tests were performed in accordance with Arizona Test 733 and 736, respectively. The results of these corrosivity tests are presented in Appendix B.

The soil pH values of the selected sample tested from our borings were 8.0, which is considered to be alkaline. The minimum electrical resistivity of the sample tested was 3,176 ohm-cm, which is considered non-corrosive to ferrous materials. The chloride content of the sample tested was

13 ppm, which does not indicate a corrosive environment for ferrous materials. The soluble sulfate content of the soil samples tested was 0.002, which is considered to represent negligible sulfate exposure for concrete.

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10.6 Concrete

Laboratory chemical tests performed on an on-site soil samples indicated a sulfate content of

0.002 percent by weight, which represents a negligible sulfate exposure for concrete. Based on the following American Concrete Institute (ACI) table (Table 4), the on-site soils should be considered to have negligible sulfate exposure to concrete. Based on the sulfate test results, and based on our experience with similar soil conditions, the specific use of the facility, and nearby practice, we however recommend the use of sulfate resistant cement (Type II or similar) for construction of concrete structures at this site. Due to potential uncertainties as to the use of reclaimed irrigation water, or topsoil that may contain higher sulfate contents, pozzolan or admixtures designed to increase sulfate resistance may be considered.

Table 4 – ACI Requirements for Concrete Exposed to Sulfate-Containing Soil

Sulfate Exposure

Water- Soluble Sulfate (SO4) in

Soil, Percentage by Weight

Cement Type

Water- Cementitious

Materials Ratio, by Weight, Normal-Weight

Aggregate Concrete1 f’c, Normal-Weight and Lightweight Aggregate Concrete, psi x 0.00689 for MPa

Negligible 0.00 - 0.10 -- -- --

Moderate2 0.10 - 0.20

II, IP(MS), IS

(MS)

0.50 or less 4,000 or more

Severe 0.20 - 2.00 V 0.45 or less 4,500 or more

Very severe Over 2.00 V plus pozzolan3

0.45 or less 4,500 or more

Notes:

A lower water-cementitious materials ratio or higher strength may be needed for low permeability or for protection against corrosion of embedded items or freezing and thawing (ACI Table 4.2.2).

Seawater.

Pozzolan that has been evaluated by test or service record to improve sulfate resistance when used in concrete containing Type V cement.

We recommend that the structural concrete have a water-cementitious materials ratio no more than 0.50 by weight for normal weight aggregate concrete. The structural engineer should ultimately select the concrete design strength based on the project specific loading conditions.

Higher strength concrete may be selected for increased durability and resistance to slab curling and shrinkage cracking.

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10.7 Pre-Construction Conference

We recommend that a pre-construction conference be held. Representatives of the owner, civil engineer, the geotechnical consultant, and the contractor should be in attendance to discuss the project plans and schedule. Our office should be notified if the project description included herein is incorrect, or if the project characteristics are significantly changed.

10.8 Construction Observation and Testing

During construction operations, we recommend that a qualified geotechnical consultant perform observation and testing services for the project. These services should be performed to evaluate exposed subgrade conditions, including the extent and depth of overexcavation, to evaluate the suitability of the on-site materials for use as fill and to observe placement and test compaction of fill soils. If another geotechnical consultant is selected to perform observation and testing services for the project, we request that the selected consultant provide a letter to the owner, with a copy to Ninyo & Moore, indicating that they fully understand our recommendations and they are in full agreement with the recommendations contained in this report. Qualified subcontractors utilizing appropriate techniques and construction materials should perform construction of the proposed improvements.

11 LIMITATIONS

The field evaluation, laboratory testing, and geotechnical analyses presented in this geotechnical report have been conducted in general accordance with current practice and the standard of care exercised by geotechnical consultants performing similar tasks in the project area. No warranty, expressed or implied, is made regarding the conclusions, recommendations, and opinions presented in this report. There is no evaluation detailed enough to reveal every subsurface condition. Variations may exist and conditions not observed or described in this report may be encountered during construction. Uncertainties relative to subsurface conditions can be reduced through additional subsurface exploration. Additional subsurface evaluation will be performed upon request. Please also note that our evaluation was limited to assessment of the geotechnical aspects of the project, and did not include evaluation of structural issues, environmental concerns, or the presence of hazardous materials.

This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires additional information or has questions regarding the content, interpretations presented, or completeness of this document.

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This report is intended for design purposes only. It does not provide sufficient data to prepare an accurate bid by contractors. It is suggested that the bidders and their geotechnical consultant perform an independent evaluation of the subsurface conditions in the project areas. The independent evaluations may include, but not be limited to, review of other geotechnical reports prepared for the adjacent areas, site reconnaissance, and additional exploration and laboratory testing.

Our conclusions, recommendations, and opinions are based on an analysis of the observed site conditions. If geotechnical conditions different from those described in this report are encountered, our office should be notified and additional recommendations, if warranted, will be provided upon request. It should be understood that the conditions of a site could change with time as a result of natural processes or the activities of man at the subject site or nearby sites.

In addition, changes to the applicable laws, regulations, codes, and standards of practice may occur due to government action or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has no control.

This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions, and/or recommendations of this report by parties other than the client is undertaken at said parties’ sole risk.

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12 REFERENCES

Aerial Photograph Review, Mohave County; dated 1990, 2005, 2010, 2013, 2015, 2017; Google Earth; dated 1997, 2003, 2006, 2007, 2010, 2011, 2013, 2015, 2018.

American Concrete Institute (ACI), 2005, Building Code Requirements for Structural Concrete (ACI 318-05) and Commentary (ACI 318R-05).

Arizona Department of Water Resources (ADWR), “GWSI Groundwater Maps” https://gisweb.azwater.gov/waterresourcedata/.

ASTM International (ASTM), Annual Book of ASTM Standards.

Cook, 2015, Geologic Map of Quaternary and Upper Tertiary Alluvium in the Kingman 7 ½’ 30’ X 60’ Quadrangle, AZ: Arizona Geological Survey, Digital Geologic Map 113:

scale 1:24,000.

Euge, K.M., Schell, B.A., and Lam, I.P., 1992, Development of Seismic Acceleration Contour Maps for Arizona: Arizona Department of Transportation Report No. AZ 92-344: dated September.

International Code Council (ICC), 2015, International Building Code (IBC).

Maricopa Association of Governments (MAG), 2018, Uniform Standard Specifications and Details for Public Works Construction.

Ninyo & Moore, In-house proprietary information.

Occupational Safety and Health Administration (OSHA), Title 29 of the Code of Federal Regulations (CFR), Part No. 1926 - Safety and Health Regulations for Construction, Subpart P - Excavations.

Pearthree, P.A., 1998, Quaternary Fault Data and Map for Arizona: Arizona Geological Survey, Open-File Report 98-24.

Schumann, H.H. and Genualdi, R., 1986, Land Subsidence, Earth Fissures, and Water-level Changes in Southern Arizona: Arizona Geological Survey OFR 86-14: scale 1:500,000.

Structural Engineers Association of California, California’s Office of Statewide Health Planning and Development, 2018, page URL: https://seismicmaps.org/.

United States Department of Agriculture (USDA), Soil Survey website.

http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx.

United States Geological Survey (USGS), 2018, Rattlesnake Hill, Arizona, 7.5-Minute Series (Topographic): scale 1 = 24,000.

Wiggins, D. (2018). I-40 Rancho Santa Fe Traffic Interchange Addendum (Rep.). AZ: AECOM.

https://gisweb.azwater.gov/waterresourcedata/ https://seismicmaps.org/ http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx

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Appendix A

Photographic Documentation

FIGURES

FIGURE 1

b sm f ile n o vm a p

605987001 | 3/19

AIRWAY AVENUE DRAINAGE CHANNEL

KINGMAN, ARIZONA

SITE LOCATION

NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.

Approximate Scale in Feet

N

SITE

SITE

Source: The Thomas Guide, Phoenix Metro Edition, 2011.

Source: Phoenix Mapping Company, Phoenix Metro Edition, 2012.

Source: Phoenix Mapping Company, Tucson Metro Edition, 2010.

Source: The Thomas Guide, Tucson Metro Edition, 2009.

Source: Phoenix Mapping Company, Yavapai CountyEdition, 2010.

Source: Phoenix Mapping Company, Pinal County Edition, 2010.

Source: Phoenix Mapping Company, Pima County Edition, 2010.

Source: The Thomas Guide, Arizona State Edition, 2009.

APPROXIMATE

SITE LOCATION

Source: MacVan, Denver Metro Edition, 2010.

Source: Key Maps, Inc.,Houston Metro Edition, 2009.

Source: US Geological Survey 7.5-minute topographic map, Douglas, Arizona, rev. 1978.

RED MOUNTAIN FREEWAY

BASELINE ROAD

S C

O T

T S

D A

L E

R O

A D

MAIN STREET

32ND AVENUE

MAIN STREET

RED MOUNTAIN FREEWAY

BASELINE ROAD

S C

O T

T S

D A

L E

R O

A D

M…