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JACKSONVILLE PLANNING ADVISORY BOARD REGULAR MEETING AGENDA October 9, 2017 6:00 P.M. COUNCIL CHAMBERS JACKSONVILLE CITY HALL I. CALL TO ORDER II. PLEDGE OF ALLEGIANCE III. INVOCATION IV. APPROVAL OF THE AGENDA V. REVIEW & APPROVAL OF THE MINUTES Regular Meeting – September 11, 2017 VI. CITY COUNCIL UPDATE – Councilman Robert Warden VII. OLD BUSINESS - None VIII. NEW BUSINESS A. Building Ad Hoc Development Committee Report IX. REPORTS A. Interim Planning & Inspections Director X. ADJOURNMENT 1
Transcript
Page 1: JACKSONVILLE PLANNING BOARD

JACKSONVILLE PLANNING ADVISORY BOARD REGULAR MEETING AGENDA

October 9, 2017 6:00 P.M.

COUNCIL CHAMBERS JACKSONVILLE CITY HALL

I. CALL TO ORDER

II. PLEDGE OF ALLEGIANCE

III. INVOCATION

IV. APPROVAL OF THE AGENDA

V. REVIEW & APPROVAL OF THE MINUTES

Regular Meeting – September 11, 2017

VI. CITY COUNCIL UPDATE – Councilman Robert Warden

VII. OLD BUSINESS - None

VIII. NEW BUSINESS

A. Building Ad Hoc Development Committee Report

IX. REPORTS

A. Interim Planning & Inspections Director

X. ADJOURNMENT

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JACKSONVILLE PLANNING ADVISORY BOARD REGULAR MEETING AGENDA

SEPTEMBER 11, 2017, 6:00 p.m.

COUNCIL CHAMBERS JACKSONVILLE CITY HALL

Present: Homer Spring, Al Keyes, Doug Lesan, Theresa VanderVere, Jim Dorn, and

Suzanne Nelson.

Absent: Thomasine Moore, Albert Burgess, and Steve Forney.

Others

Present:

Bob Warden, Ryan King, Jeremy Smith, and Pam Ramsey.

I. CALL TO ORDER

The regularly scheduled Jacksonville Planning Advisory Board meeting was called to

order by Chairman Doug Lesan at 6:00 pm on Monday, September 11, 2017 in Council

Chambers at Jacksonville City Hall.

II. PLEDGE OF ALLEGIANCE

Jim Dorn led the Board in reciting the Pledge of Allegiance.

III. INVOCATION

Homer Spring gave the invocation.

IV. APPROVAL OF THE AGENDA

Theresa VanderVere moved to approve the agenda as presented. Homer

Spring seconded the motion.

The motion to approve the agenda as presented was unanimously approved

by the Board Members present.

V. REVIEW & APPROVAL OF THE MINUTES

Regular Meeting - August 14, 2017

Homer Spring moved to approve the minutes as presented. Jim Dorn

seconded the motion.

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The motion to approve the minutes as presented was unanimously approved

by the Board Members present.

VI. CITY COUNCIL UPDATE – Councilman Robert Warden

Councilman Warden gave a report.

VII. OLD BUSINESS - None

There was no old business.

VIII. NEW BUSINESS

A. Special Use Permit and Type III Site Plan – ABRA Body and Glass – 2301 Lejeune

Boulevard

ABRA Body and Glass has submitted a Special Use Permit and Type III Site Plan

application seeking approval of a proposed 2,738 square foot automotive paint and

body shop. The 1.33 acre development site is located at 2301 Lejeune Boulevard, zoned

Corridor Commercial (CC). This project as proposed will be adjacent to and part of the

existing ABRA Body and Glass, although the plan was designed so that it could operate

independently. A Special Use Permit is required for an automotive paint and body shop

in the CC zoning district.

The proposed development is within the City limits and as proposed would not impact

the City’s Sewer Allocation Policy.

The subject parcel is designated as Regional Commercial (RC) by the CAMA future land

use map. Properties to the North, East, and West, are also designated RC by the CAMA

future land use map. Regional Commercial provides areas for large scale commercial

operations and mixed use developments. Land allocated to RC uses shall have access to

a thoroughfare. The proposed use is consistent with the Regional Commercial CAMA

designation.

The proposed development is located within the City limits and is zoned Commercial Corridor (CC). The site is bordered to the North, by undeveloped property zoned CC; to the west by ABRA Auto and Glass zoned CC; to the east, by vacant properties zoned CC; and to the south by Tarawa Terrace. Per Article 5: Development Standards, Section 5.1: Off-Street Parking, Loading, and Circulation of the Unified Development Ordinance (UDO), the proposed use has a parking requirement of 1 space per 250 square feet of building area. The required minimum parking is 12 spaces, with a maximum allowable being 64. As proposed the

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development is providing the minimum number required, 12 spaces. All adjacent properties are zoned CC, therefore no buffering is required beyond the standard landscaping requirements which is a 4 foot perimeter lawn with shrubs and understory trees. Per Article 5: Development Standards, Section 5.5: Exterior Lighting of the UDO the following standards shall be met and/or maintained; 1) maximum lighting height shall not exceed 30 for new development locating adjacent to lower intensity development, 2) maximum illumination levels are allowed up to 2.5 foot candles; and 3) all proposed lighting shall be directed downward thereby maintaining a “dark sky” standard. At this time lighting is not proposed for this development. Any future lighting will be required to meet the standards in place at the time the permit application is received. The proposed development site is not located within the Flight Path Overlay District (FPOD). Staff recommend approval of the Special Use Permit and Type III Site Plan based on Findings of Facts A, B, C, E, F and G being found in the affirmative and D mitigated by the filing of a revised site plan.

Homer Spring moved to approve the Special Use Permit and Type III Site

Plan based on Findings of Facts A, B, C, E, F and G being found in the

affirmative and D mitigated by the filing of a revised site plan. Theresa

VanderVere seconded the motion.

The motion to approve the Special Use Permit and Type III Site Plan based

on Findings of Facts A, B, C, E, F and G being found in the affirmative and D

mitigated by the filing of a revised site plan was unanimously approved by

the Board Members present.

IX. REPORTS

A. Interim Planning & Inspections Director

Ryan King gave a report.

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X. ADJOURNMENT

Al Keyes moved to adjourn at 6:19pm. Jim Dorn seconded the motion.

The motion to adjourn at 6:19pm was unanimously approved by the Board

Members present.

Adopted this 9th day of October 2017 for the 11th day of September, 2017.

Doug Lesan, Chairman ATTEST:

Pamela Ramsey Permitting Specialist Supervisor

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Report to the Planning Advisory Board

Agenda Item: A Date: 10/9/2017

Subject: Building Ad Hoc Development Committee Report

Department: Planning and Inspections

Presented by: Ryan King, Interim Director of Planning and Inspections

Issue Statement During City Council’s FY18 budget workshops, the City Manager’s Office (CMO)

discussed concerns about the lack of residential development within the City. Dr. Woodruff informed the Mayor and Council that an Ad Hoc Committee of the development community would be assembled to determine issues that may be discouraging residential development within the City. Over the last 3 months, CMO and staff have met with the Ad Hoc Committee. From those meetings, the Committee identified 10 issues they felt were affecting the costs of residential development. Staff has analyzed these issues and presented these recommendations for changing the UDO or MSSD. On September 22nd, the Mayor and Council gave support to the recommendations. Amendments will now be scheduled for formal amendments on future Planning Advisory Board and/or Council agendas.

Action Needed Receive Presentation

Attachments:

A Background information

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Ad Hoc Development Committee Staff Supported Recommendations

1. City facilities fees: Consider establishing a phased in partial payment program so thedeveloper does not have to “front” the cost at time of permit issuance.

Staff Recommendation Beginning August 9, 2017 and continuing for a period until Friday, October 13, 2017, the City will conduct a pilot project during which time the system development fees will be collected only at the time the request for a Final Inspections is made. This means that when the request for final inspection is made, the fee must be paid before the final inspection is made.

2. Stormwater Escrow Account: Consider reducing or eliminating the amount that thedeveloper must pay into the HOA-type stormwater BMP escrow account. Assignmore or all of the funding responsibility to the HOA.

Staff Recommendation Consult the Stormwater Advisory Committee (SWAC) about changes to the City’s requirement for establishment and funding of escrow accounts for BMPs maintained by a homeowners' association, property owners' association, or similar entity. The alternatives that Staff proposes to discuss with the SWAC are:

No change to the current requirements

Replace the current escrow account funding requirements with one thatrequires the developer to record, and reference on the record plat, amaintenance plan that instructs the property owners association or lot ownerabout the annual maintenance tasks and associated costs for at least a 20-year period. A second requirement would call for the developer to record amaintenance agreement, or restrictive covenant that sets forth the propertyowners’ association or lot owners’ continuing responsibilities for maintenance,including specifying how cost will be apportioned among lot owners served.

Establish a City stormwater facility replacement fund to ensure that adequatefunds are available to the City for the maintenance, repair, replacement andreconstruction of stormwater control facilities should a homeownersassociation fail to perform any of these necessary functions. Monies for thefund would come from developers of property. The amount paid by adeveloper would be based on a percentage of the estimated stormwatercontrol facilities he/she will construct. The City would recover from theassociation and its members any and all costs the City expends to maintainor repair the structural BMPs or to correct any operational deficiencies.

3. Stormwater Design: Eliminate or reduce City requirements that are seen as barriersto low-density projects.

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Staff Recommendation City staff has evaluated MSSD requirements for streets, sidewalks, curb and gutter, and cul-de-sacs. Staff recommendations are provided for each in Items 4, 5, and 6.

4. MSSD Street Standards: Consider reducing requirements for street width, cul-de-sac

diameter, base course depth, and asphalt thickness. Staff Recommendations City staff recommends the following concerning current dimensional requirements for residential streets:

1. Allow NCDOT-type widths for residential streets with curb and gutter as an alternative to current requirements as long as, off-street parking is provided. Adoption of this recommendation by Council will require Council to rescind its prior adoption of Appendix D of the North Carolina Fire Prevention Code since it essentially requires minimum street widths of 26 feet. A table that summarize the City’s current residential street width requirements and the alternate proposed by Staff are provided as Attachment 1.

2. Reduce the required minimum diameter for cul-de-sacs. Staff suggests a minimum cul-de-sac diameter of 80 feet measured to the face of the curb versus the current standard of 96 feet. Implementation of this change will also necessitate rescinding Council’s prior adoption of Appendix D since it requires minimum cul-de-sac diameters of 96 feet.

City staff recommends the following concerning current pavement construction standards for residential streets:

1. Delete the requirement for placement of engineering fabric within the pavement structure of residential collector streets. Designate the City’s current requirements with this one change as the “standard requirements.”

2. Revamp Section 3 of the MSSD street design guideline titled “Pavement Design” to make it easier for designers to propose alternate pavement designs. Under this scenario, the developer and his/her designer could opt to construct streets in accordance with current requirements or propose alternate pavement sections that have been derived via use of a new, design procedure provided by Section 3. A description of the recommended design procedure is provided as Attachment 2. The differences between the pavement construction details from use of this alternate method versus the current standards would be as follows:

a. The base course thickness would be 6 inches for local residential streets where good to excellent subgrade soils exist versus the standard requirement of 8 inches.

b. The residential collector pavement section would consist of 2½ inches of asphalt on 8 inches of aggregate base course where good to excellent subgrade soils exist. The standard requirement for a residential collector is 2 inches of asphalt surface course on 4 inches of

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an asphalt base course that is in turn, underlain by 8 inches of aggregate base course.

c. The residential collector pavement section would consist of 1½ inches of asphalt surface course on 2½ inches of an asphalt intermediate course that is in turn, underlain by 8 inches of aggregate base course where fair to poor subgrade soils exist. Again, the standard requirement for a residential collector is 2 inches of asphalt surface course on 4 inches of an asphalt base course that is in turn, underlain by 8 inches of aggregate base course.

The geotechnical consultant that developed the proposed design procedure has proposed a 2½-inch asphalt surface course for a local residential road constructed on fair to poor subgrade soils versus the current standard requirement of 2 inches. City Staff proposes to retain the current standard of 2 inches for this condition.

5. MSSD Curb & Gutter Requirement: Consider eliminating requirement for concrete

curb & gutter along streets. Staff Recommendation: After careful consideration and much discussion, City staff does not support the construction of streets with roadside ditches/swales in lieu of streets with curb and gutter.

6. MSSD Sidewalk Requirement: Consider eliminating requirement for concrete sidewalks on both sides of City streets or require only on one side of streets. Staff Recommendation: Staff recommends retaining a requirement for sidewalks but supports an alternative to the current sidewalk requirement. Therefore, Staff intends to present the following options for Council consideration:

Maintain current requirements that generally call for 4-foot sidewalks on both sides of residential streets.

Institute a requirement for a 6-foot wide sidewalk on one side of all streets with the exception of cul-de-sacs with 6 or fewer lots in lieu of the requirement for sidewalks on both sides of streets.

Amend current standards to incorporate both options. Under this scenario, one of the two options would be constructed throughout the initial development as well as, the future sections/phases of the development.

7. Letter of Credit: Consider a shorter time period for the Letter of Credit.

Staff Recommendation The UDO and MSSD currently require performance guarantees and a warranty. Prior to recent legislation changes, the City required a performance guarantee to cover the estimated cost of infrastructure improvements plus an additional 10 percent. Once the improvements were accepted by the City, the City allowed the developer to

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reduce the performance guarantee to 10 percent of the total cost (excluding sidewalks) which the City then held for the remainder of the 18-month warranty period. This requirement tied-up a portion of the developers’ money for additional 18 months past acceptance of the infrastructure. Legislation changes, covered in the Discussion section of this item, no longer allow the City to withhold the performance guarantee through the warranty period. Staff recommends revising Section 5.14 B. Warranties of the UDO as follows:

B. Warranties General A warranty in accordance with the standards in this section is required in the following circumstances:

To ensure against defects in workmanship or materials in providing infrastructure improvements required as part of an approved Subdivision (Section 2.3.E), or Site Plan (Section 2.3.C).

Term of Warranties The term of a warranty for required infrastructure improvements shall be that which is stated in the City of Jacksonville’s Manual of Standards, Specifications, and Design (latest version) from the date of acceptance. Form of Warranties Where required, the developer shall furnish a warranty in any of the following acceptable forms:

Cash (in US currency) deposit with the City; Certified check from a North Carolina financial institution

based upon a cash deposit, bearing the name of the developer, and in a form acceptable to the City Attorney and Finance Director;

Irrevocable letter of credit from a banking institution located and incorporated in North Carolina in a form acceptable to the City Attorney and Finance Director. This may include the ability for the letter of credit to be cashed in Onslow County;

A certificate of deposit in the name of and payable to the City of Jacksonville, referencing the name of the developer or subdivider; or

Other financial instruments including land or finished and developable lots which are acceptable to the City Attorney and City Manager may be provided for unconstructed sidewalks only.

The warranty shall be conditioned on the performance of all work necessary to maintain required public infrastructure improvements during the term of the warranty. Warranties shall provide that in

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case of the developer’s failure to maintain and repair the infrastructure during the term of the warranty, the City shall be able to immediately obtain the funds necessary to make necessary repairs or replacements. Amount of Warranties Warranties shall be in an amount equal to at least 10 percent of the full actual cost, including the costs of materials and labor, of installing the required improvements. Actual costs for installing required improvements shall be itemized by improvement type and certified by a licensed professional engineer, or land surveyor or licensed landscape architect and shall be approved by the Public Services Director and/or Development Services Director, whichever is applicable. Warranties for Developments Outside Corporate limits or with Private Streets Inspection Required for City Infrastructure Once improvements are complete, the developer shall submit, in writing, a request to the City for a final inspection. The City shall inspect the subdivision, and if deficiencies are found, the City shall notify the developer by certified mail. Once the corrections have been satisfactorily completed, the City will notify the developer by certified mail and reduce the warranty to a revised amount for incomplete sidewalks, if appropriate . a request for City Council to consider accepting the public infrastructure and will provide a signed, written Warranty Guarantee to be placed on the Council’s agenda. If accepted, the developer shall be responsible for Warranty Period as defined by the Manual of Specifications, Standards, and Design, Latest Revision. Upon satisfactory completion of the Warranty Period, the City will be responsible for all operation and maintenance of said infrastructure. Warranty Period Because the City may not accept improvements outside the City Limits and because some subdivisions designate their streets as private, the following shall govern the warranty period.

Warranty for private streets. A financial guarantee is required for the warranty period unless a Homeowner's Association has been organized and documentation recorded which addresses the upkeep and maintenance of streets. Warranty for NCDOT streets. If a Homeowner's Association has been organized and documentation recorded which addresses the upkeep and maintenance of streets and addresses the petition process for NCDOT acceptance, no warranty period for streets will be required. Additionally, if the developer can

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provide documentation that the streets have been included on the State system; no warranty guaranty for street will be required.

Release of Warranties The Director of Public Services shall inspect the improvements approximately three months prior to the expiration of the warranty term. Release of a warranty shall only occur after City staff has performed an inspection of the infrastructure and certified in writing that the guaranteed improvements have been maintained in accordance with approved plans and specifications. Extension of Warranties A developer may request an extension for an expired warranty period to repair damaged infrastructure or dead vegetation. Default and Forfeiture of Guarantee If the developer fails to maintain the guaranteed improvements during the term of the warranty, the Director of Public Services shall give the developer 30 days written notice of the default by certified mail.

8. Water and Sewer Bills: Consider a lower bill after the Certificate of Occupancy and before sell of home.

Staff Recommendation Staff recommends implementing a contractor rate for new single-family construction that may be applied until the house is sold or occupied (whichever comes first) that includes the water rate and stormwater fee as identified in the adopted Fee Schedule.

9. Permit fees/review process: Analyze to see what can be eliminated and simplify the process.

Recommendation City staff recommends amending the current single-family fee to $.45 per square foot and reducing the technology fee to 5% for single-family only as ePlan is not currently used for single-family. This would mean a target house of 1,700 square feet would cost approximately $14 more than Onslow County’s Fee. Under this scenario permit fees for smaller homes would be cheaper in Jacksonville than in Onslow County.

Staff has also evaluated the Stormwater Review, Erosion and Sedimentation Control, and Engineering Inspection Fees. These fees are based on actual costs to perform reviews and are in general comparison with other entities. No changes are recommended to these fees.

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10: Minimum foundation height requirement: Consider reducing foundation height requirement.

Recommendation Staff recommends maintaining the 18-inch minimum for exposed foundation in the downtown zones but supports a small reduction for all other zones. Staff recommends amending Section 5.11 of the UDO from 12 to 8 inches using the following language: Eight (8) inches (minimum) of exposed foundation shall be provided above the finish grade. A masonry, stucco or decorative concrete exposed foundation or decorative band of at least 12 inches in height shall be provided around

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Attachment 1 Current and Proposed Alternate Street Width Requirements

City Staff supports NCDOT-type widths for residential streets with curb and gutter as an alternative to current requirements as long as, off-street parking is provided. The following table summarize the City’s current residential street width requirements and the alternate requirements proposed by Staff.

SUMMARY TABLE

Street Width measured from:

Edge-of-Pavement

to

Edge-of-Pavement

Back-of-Curb

to

Back-of-Curb

Minor Street (i.e. Local

Street)

Standard Requirement 27 ft. 31 ft. No

Alternative Standard 22 ft. 26 ft. Yes

Collector Street

Standard Requirement 33 ft. 37 ft. No

Alternative Standard 30 ft. 34 ft. Yes

Notes:

1. Listed widths assume construction of a 2 ft. wide curb & gutter section.

2. The residential street alternative design may be used provided adequate off-street

parking meets the level of parking demand generated by the residential use, allows for the safe movement of passengers from parking space to residence, and reduces

parking impacts on roadways. Off-street minimum parking requirements shall be as

follows –

a. Two (2) off-street parking spaces shall be provided for each 1-bedroom single

family dwelling.

b. Three (3) off-street parking spaces shall be provided for each 2- and 3-

bedroom single family dwelling.

c. Four (4) off-street parking spaces shall be provided for each single family

dwelling of four or more bedrooms.

d. Two (2) off-street parking spaces shall be provided for each 1-bedroom multi-

family dwelling.

e. Three (3) off-street parking spaces shall be provided for each 2- and 3-

bedroom multi-family dwelling.

f. Four (4) off-street parking spaces shall be provided for each multi-family

dwelling of four or more bedrooms.

g. Minimum dimensions for an individual off-street parking space shall be 9 ft. x

18 ft.

h. Off-street parking spaces shall be located beyond the street right-of-way and

within the limits of the driveway(s) or dedicated, paved parking spaces.

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i. The garage shall not count toward the minimum number of spaces

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Attachment 2

Excerpts from: Draft Pavement Design Recommendations Report Pavement Design Policy Rewrite City of Jacksonville By: S&ME 3006 Hall Waters Drive, Suite 100 Wilmington, NC Date: May 13, 2015

Includes Introductory Commentary by City of Jacksonville Staff

August, 2017

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City of Jacksonville Staff Commentary

City staff has been considering a re-write of Section 3 of the MSSD street design

guideline titled “Pavement Design” to make it easier for designers of developments to

propose alternate pavement designs. Staff asked the Wilmington, NC office of S&ME to

make recommendations to this end along with other recommendations relative to the

City’s street-related requirements. Below is a reprint of a portion of the report that

resulted from S&ME’s efforts. The portion provided below describes a proposed

pavement design procedure recommended by S&ME.

The method proposed by S&ME is based upon the selection of a pavement section

without the performance of detailed design calculations. The method proposed by

S&ME relies upon determination of soil types in the areas to be paved through the use

of the United States Department of Agriculture (USDA) Web Soil Survey and the USDA

Onslow County Soil Survey report. Selection of the pavement section is then made

based upon the type of street to be constructed and the worst soil type upon which the

pavement is to be constructed. Again, no detailed design calculations are required

when following the procedure developed by S&ME. Additionally, S&ME envisioned a

process that relies upon the USDA soils mapping without any field verification of the

mapping.

City Staff supports implementation of the S&ME recommended procedure with two

changes as follows:

Include a requirement for confirmation of the soil types that are mapped

along the route of the proposed street(s) through field investigation.

Table 2.5 of the S&ME report proposes a 2½-inch surface course for

residential local streets constructed on fair to poor subgrade soil. City Staff

proposes to retain the current standard of 2 inches for this condition.

2.1.3 Standard Pavement Sections – Without Geotechnical Exploration and Detailed Design

If Section 3 of the Street Design section of the City’s Specifications, Standards, &

Design, Street Design Policy document dated, June 2006, revised 2012, Draft 1 by GKM,

is deleted, then S&ME recommends the following procedures be used by

developers/designers to determine design pavement section(s) for their projects and by

the City of Jacksonville to review the pavement design submittal and drawings:

1. Determine the soil types using Web Soil Survey

(http://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm) and the Onslow

County Soil Survey Report prepared by the United States Department of

Agriculture, Soil Conservation Service. Locate the project on the soil maps and

See Staff

Commentary

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determine the soil types in the areas to be paved. A copy of the soil survey map

with the boundaries of the property and areas to be paved shall be submitted to

the City of Jacksonville Public Services Department.

a. From the Engineering Index Properties Table, determine the AASHTO

Classification of the soil types. From this information, use Table 2-2 to

determine the General Soil Rating as Subgrade (Either Good to Excellent,

Poor to Fair, or Unsuitable). For sites with multiple soil types or soil types

with multiple AASHTO Classifications, use the lowest rating for the site.

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Table 2-2 – General Soil Rating as Subgrade

AASHTO Soil Classification

USCS Soil Classification

Usual Types of Significant Constituent

Materials

General Rating as Subgrade

A-1-a GW, GP Stone Fragments, Gravel Good to Excellent

A-1-b SW, SP Stone Fragments, Sand Good to Excellent

A-3 SP, SP-SM Fine Sand Good to Excellent

A-2-4, A-2-5 SM Silty Gravel and Silty Sand Good to Excellent

A-2-6, A-2-7 SC Clayey Gravel and Clayey Sand

Poor to Fair

A-4, A-5 ML, MH Silty Soils Poor to Fair

A-6 CL Clayey Soils Poor to Fair

A-7-5, A-7-6 CH, MH Clayey Soils Unsuitable

OL, OH, PT Organic Silt, Organic Clay, Peat, Muck

Unsuitable

b. Or, use the soil series name, soil series map symbol, and Table 2-3 to

determine the General Soil Rating as Subgrade (Either Good to Excellent,

Poor to Fair, or Unsuitable). For sites with multiple soil types, use the lowest

rating for the site.

Continued on next page

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Table 2-3 – General Soil Rating as Subgrade

USDA Soil

Series

General Rating

as Subgrade

USDA Soil Series General Rating

as Subgrade AnB - Alpin Good to Excellent MaC – Marvyn Poor to Fair

AuB – Autryville Good to Excellent Md – Masontown Unsuitable

BaB – Baymeade Good to Excellent Mk – Muckalee Poor to Fair

BmB – Baymeade,

Urban Variable Mu – Murville Good to Excellent

Bo – Bohicket Unsuitable NeE, NfC – Newhan Good to Excellent

Ca – Carteret Good to Excellent NnE – Newhan,

Corolla, Urban Variable

Co – Corolla Good to Excellent NoA, NoB – Norfolk Poor to Fair

CrB, CrC – Craven Unsuitable On - Onslow Poor to Fair

Ct – Croatan Unsuitable Pa – Pactolus Good to Excellent

Da – Dorovan Unsuitable Pn – Pantego Poor to Fair

Dc – Duckston Good to Excellent Pt – Pits Variable

FoA – Foreston Good to Excellent Ra – Rains Poor to Fair

GoA – Goldsboro Poor to Fair St – Stallings Good to Excellent

GpB – Goldsboro,

Urban Variable To – Torhunta Good to Excellent

Gt – Grifton Poor to Fair Ud – Udorthents Variable

KuB – Kureb Good to Excellent Ur – Urban Land Variable

La – Lafitte Unsuitable WaB – Wando Good to Excellent

Le – Lenoir Poor to Fair Wo – Woodington Good to Excellent

Ln – Leon Good to Excellent YaA - Yaupon Poor to Fair

Ly - Lynchburg Poor to Fair

2. Determine the Pavement Materials and Section Thicknesses

a. If the pavement subgrade soils are rated as Good to Excellent, use Table 2-4

to determine the required pavement layer materials and minimum

thicknesses.

b. If the pavement subgrade soils are rated as Poor to Fair, use Table 2-5 to

determine the required pavement layer materials and minimum thicknesses.

c. If the pavement subgrade soils are rated as Unsuitable, overexcavate

subgrade soil and/or raise grades such that soil under pavement section

consists of at least 2 feet of Good to Excellent soil placed on stabilized

subgrade. May require additional undercutting and/or woven geotextile to

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stabilize subgrade. Use Table 2-4 to determine the required pavement layer

materials and minimum thicknesses.

d. If the pavement subgrades soils are rated as Variable, a geotechnical

exploration of the subsurface conditions at the site should be performed to

determine pavement subgrade soil types and provide recommended general

rating as subgrade.

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Table 2-4 – Recommended Standard Pavement Layer Materials and Minimum

Thicknesses for Good to Excellent Subgrade Soil (Design CBR =9)

Street

Classification

Design Max.

First Year

One-Direction

ADT (vpd)

Max. %

Annual

Traffic

Growth

Max. %

Dual

Trucks

Max.

%

TTSTs

Design

Lifetime

Max.

ESALs

Required

Structural

Number

Asphalt

Surface

Course

Asphalt

Intermedia

te Course

Asphalt

Base

Course

Aggregate

Base

Course

(ABC)

Residential Local

Subdivision Street 500 1% 1% 0.5% 35,000 1.7

2.0 in.

SF9.5A -- -- 6.0 in.

Residential Collector

Street 2,500 1% 1% 0.5% 168,000 2.2

2.5 in.

SF9.5A -- -- 8.0 in.

Commercial Collector

Street (Not currently

defined)

5,000

1%

2%

1%

545,000

2.6

3.0 in.

S9.5B

--

--

9.0 in.

Frontage Road 2,500 1% 2% 1% 330,000 2.4 3.0 in.

S9.5B -- -- 8.0 in.

Boulevard 5,000 2% 2% 1% 735,000 2.8 1.5 in.

S9.5B

2.5 in.

I19.0B -- 8.0 in.

Minor Thoroughfare 10,000 2% 2% 1% 1,500,000 3.1 2.0 in.

S9.5B

2.5 in.

I19.0B -- 8.0 in.

Major Thoroughfares 20,000 2% 2% 1% 3,200,000 3.6 3.0 in.

S9.5C --

4.0 in.

B25.0C 8.0 in.

Table 2-5 – Recommended Standard Pavement Layer Materials and Minimum Thicknesses

for Poor to Fair Subgrade Soil (Design CBR=3)

Street

Classification

Design Max.

First Year

One-Direction

ADT (vpd)

Max. %

Annual

Traffic

Growth

Max. %

Dual

Trucks

Max.

%

TTSTs

Design

Lifetime

Max.

ESALs

Required

Structural

Number

Asphalt

Surface

Course

Asphalt

Intermediat

e Course

Asphalt

Base

Course

Aggregate

Base

Course

(ABC)

Residential Local

Subdivision Street 500 1% 1% 0.5% 35,000 2.2

2.5 in.

SF9.5A -- -- 8.0 in.

Residential Collector

Street 2,500 1% 1% 0.5% 168,000 2.8

1.5 in.

S9.5A

2.5 in.

I19.0B -- 8.0 in.

Commercial Collector

Street (Not currently

defined)

5,000

1%

2%

1%

545,000

3.4

2.0 in.

S9.5B

2.5 in.

I19.0B

--

10.0 in.

Frontage Road 2,500 1% 2% 1% 330,000 3.1

2.0 in.

S9.5B

2.5 in.

I19.0B -- 8.0 in.

Boulevard 5,000 2% 2% 1% 735,000 3.5

3.0 in.

S9.5B

2.5 in.

I19.0B -- 8.0 in.

Minor Thoroughfare 10,000 2% 2% 1% 1,500,000 3.9

3.0 in.

S9.5C --

5.0 in.

B25.0C 8.0 in.

Major Thoroughfares 20,000 2% 2% 1% 3,200,000 4.6

1.5 in.

S9.5C

3.0 in.

I19.0C

5.0 in.

B25.0C 8.0 in.

See Staff

Commentary

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For both tables, please note that:

Materials and minimum thicknesses are based on the maximum

estimated first year ADT, percent growth, percent trucks, and pavement

lifetime ESALs given in the table. Any values higher than these for a

proposed street project would result in thicker layers and possibly require

more durable asphalt (for example S9.5B instead of SF9.5A for surface

course).

Minimum thicknesses are also based on initial serviceability of 4.2,

terminal serviceability of 2.0, reliability of 85%, and standard deviation

of 0.45.

May reduce ABC thickness by 2 in. by placing geogrid per manufacturer’s

recommendations/requirements/specifications on stable subgrade before

ABC placement

The geogrid shall meet the properties given in Table 2-6: Table 2-6 –

Minimum Geogrid Properties

Property Test Standard Recommended Value

Aperture Dimensions -- 0.75 in. min.

Tensile Strength at 5%

Strain

ASTM D6637 800 lb/ft min

Ultimate Tensile Strength ASTM D6637 1300 lb/ft min

Single Junction (Node)

Strength Efficiency

GRI GG2 93% min.

Flexural Stiffness ASTM D5732 750 g-cm min.

In-Plane Torsional Stiffness

(Aperture Stability)

GRI GG9 0.6 m-N/deg min.

95% min. for SC

93% min. for SW

90% min. for GP

Resistance to Long Term

Degradation

EPA 9090 100% min.

Resistance to UV

Degradation

100% min.

Surface Course should be placed in two lifts of equal thickness

Top lift of surface course of asphalt should not be placed on residential streets

until at least 75 percent of lots along street are built out. Evaluate, patch, and

repair initial lift of surface course asphalt and ABC, as necessary, prior to top

lift placement.

If pavement design based on Table 2-2, subgrade conditions must be verified

during to ensure at least 2 feet of firm, stable, compacted Good to Excellent

subgrade soils underlie pavement section. If not, contractor should excavate

and remove Poor to Fair soils and replace them with compacted Good to

Excellent soils.

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Soil placed as fill under pavements should be compacted to

At least 95 percent of its standard Proctor maximum dry unit weight more than

1 foot below design bottom of pavement section elevation

At least 98 percent of its standard Proctor maximum dry unit weight within 1

foot of the design bottom of pavement section elevation

Between +/- 3 percent of its standard Proctor optimum moisture content for

Poor to Fair soils

Between +/- 5 percent of its standard Proctor optimum moisture content for

Good to Excellent soils

3. Example - A proposed residential collector street is shown on Figure 2. The

Soil Series which is crosses and their General Ratings as Subgrade are:

On – Onslow (Poor to Fair)

Wo – Woodington (Good to Excellent)

Ra – Rains (Poor to Fair)

Mu – Murville (Good to Excellent)

Pa – Pactolus (Good to Excellent)

The lowest rating for the site is Poor to Fair. Use the pavement section for a

residential collector street given in Table 2-5.

Please note that the section of the proposed residential collector street in the

eastern part of the site generally has Good to Excellent pavement subgrades soil

(Mu, Pa, and Mu), with nearby Poor to Fair pavement subgrade soil (On).

However, the soil maps are approximate and not necessarily accurate enough to

accurately distinguish actual boundaries between soil series. Therefore, if the

subsurface conditions were further evaluated and confirmed by a geotechnical

exploration, it may be possible to use the less-conservative pavement section for a

residential collector street given in Table 2-4.

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