FinalPaveMemo_ME.pdf

Page 1 of 6 Pages

Form FHWA-201 (Rev. 11-67)

U.S. DEPARTMENT OF TRANSPORTATION

FEDERAL HIGHWAY ADMINISTRATION

Use this form in lieu of transmittal slips within Dept. of Trans. When message comment is to be retained as file material. Do not prepare carbons. Not to be used in lieu of Form FHWA- 121 for informal correspondence. MINUTE-MEMO

M:\PROJECTS\maca\13(1)_14(2)\Techserv\Pavement\Correspondence\MACA 13(1), 14(2) 99% Final Pavement Memo.doc

SUBJECT: Pavement Recommendation for MACA 13(1), 14(2)

TO MESSAGE/COMMENT FROM/DATE

M. Tessitore PS&E Project Manager

And:

D. Hassan Acting Highway Design Manager

To support developing 99% PS&E, we’re submitting our final pavement recommendations for MACA 13(1), 14(2). The project site is located in Edmonson County, KY. The project consists of the rehabilitation of approximately 0.2 miles of MACA-0013 (Green River Ferry Road South) from the Green River Ferry to MACA-0915 (Green River Ferry Parking) and approximately 0.2 miles of MACA-0014 (Green River Ferry Road North) from the Green River Ferry to a gravel pullout on the south side of MACA-0014. The project also consists of extending the concrete boat ramps at the terminus of MACA-0013 and beginning of MACA-0014. In addition, MACA-0010 (Mammoth Cave Parkway) will receive shoulder hardening at spot locations.

Green River Ferry Road North and South The Green River Ferry Road South between the Green River Ferry Parking and South Ferry Ramp and the Green River Ferry Road North consist of an asphalt surfaced road. During our Field Investigation on March 21-23, 2016, the roads were observed to have little to no surface distresses on the pavement wearing course.

These roads currently have a weight restriction based on the ferry capacity. The current ferry capacity is 8-tons. The park has mentioned that it may retrofit the ferry and increase the capacity to 12-tons in the future.

The apparent width of the roadway measured to be about 32-feet at the stone retaining walls to 24-feet at the boat ramp. Both roads had concrete curb & gutters for drainage. It should be noted that this crossing has significant flooding events on a regular basis which should be considered during design.

Subsurface investigation, consisting of 4 borings, was done on multiple sections of these roads. The roads appear to be 6-inches of asphalt overlaid on top of 12-inches of crushed aggregate. The subgrade was sampled down to 15-feet. The subgrade from 1 to 3-feet consists of AASHTO A-1-A (Gravel with silt and sand). The subgrade below 3-feet consists of AASHTO A-4(2) (Silty Sand) and A-4(1) (Sandy Silty Clay).

The northernmost boring on Green River Ferry Road North (approximately 300 yards north of the north Ramp ferry crossing) revealed bedrock at 2.3-feet below the surface. Cores at this section revealed 6-inches of asphalt over 18-inches of road base on top of bedrock. Designers should be aware that lowering the grade on Green River Ferry Road North deeper than 1-foot may warrant further subsurface investigation in this area.

We recommend milling the existing pavement 1 ½-inches in depth and overlay with Asphalt Concrete Pavement 1 ½-inches in depth in accordance with Table 1.

Steve Deppmeier Pavement Engineer

Through:

Anthony Maloche for Mohammed Elias Acting Pavement Team Leader

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Table 1. Green River Ferry Road Mill and Overlay

Layer Minimum Thickness

(in)

Comments

AC Surface Course 1 1/2

Asphalt Concrete Pavement, as per Section 403 Type I of the FP-14

Specifications

Asphalt Tack Coat --- AC Tack Coat as per Section 412 of the

LOS

This rehabilitation will allow a transition into and out of the following reconstruction of the ferry ramps.

Green River Ferry Road Ramps (North and South)

The ferry ramps consist of reinforced concrete pavement at the end of MACA-0013 and the beginning of MACA-0014. Subsurface investigation was done on both ramps and the existing concrete ramps are 8-inches of reinforced concrete slabs over 12-inches of gravel base. For those portions of the upper ramps that will be normally dry we recommend keeping the existing ramp section of 8-inches of Reinforced Concrete over a minimum of 12-inches of crushed aggregate in accordance with Table 2.

Table 2. Green River Ferry Ramps

Minimum Thickness

Reinforced Concrete Pavement

Reinforced Minor Concrete Pavement per Section 501 of the FP-14 Specifications

Aggregate Base Course 12 Roadway Aggregate, Method 2, per

Section 302 of the FP-14 Specifications

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For the lower ramp portions that will be in a wet condition we are recommending 8-inches of Reinforced Concrete over a minimum of 24-inches of surge rock in accordance with Table 3.

Table 3. Green River Ferry Ramps

Minimum Thickness

Reinforced Concrete Pavement

Reinforced Minor Concrete Pavement per Section 501 of the FP-14 Specifications

Structural Backfill 24 Structural Backfill, as per Section 208 and Subsection 704.04 of the SCR

Geotextile --- Separation and Stabilization Geotextile

Class 1 – Type E, per Section 207 of the FP-14 Specifications

Green River Ferry Road North New Paved Parking

The existing surface is graveled. The existing surface should be excavated, graded to drain, scarified, reconditioned, and overlaid with 10-inches of Roadway Aggregate and then topped with 5-inches of Asphalt Concrete per the layers as outlined in Table 4.

Table 4. Green River Ferry Road North New Paved Parking

Minimum Thickness

Course 2

Asphalt Concrete Pavement, as per Section 403 Type I of the FP-14

Specifications

Asphalt Tack Coat --- AC Tack Coat as per Section 412 of the

LOS

AC Base Course 3 Asphalt Concrete Pavement, as per

Section 403 Type I of the FP-14 Specifications

Crushed Aggregate 10 Roadway Aggregate, Method 2, per

Section 302 of the FP-14 Specifications

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Mammoth Cave Parkway Shoulder Hardening

Shoulder Hardening of 1 to 3-feet in width at various locations are recommended on MACA-0010 and should consist of a separation-stabilization geotextile, 10-inches of roadway aggregate, and overlay with 5-inches of Asphalt Concrete per the layers as outlined in Table 5.

Table 5. Mammoth Cave Parkway

Minimum Thickness

Course 2

Asphalt Concrete Pavement, as per Section 403 Type I of the FP-14

Specifications

Asphalt Tack Coat --- AC Tack Coat as per Section 412 of the

LOS

AC Base Course 3 Asphalt Concrete Pavement, as per

Section 403 Type I of the FP-14 Specifications

Crushed Aggregate 10 Roadway Aggregate, Method 2, per

Section 302 of the FP-14 Specifications

Geotextile --- Separation and Stabilization Geotextile

Class 1 – Type E, per Section 207 of the FP-14 Specifications

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Appendix A – Photos of Green River Ferry Road

Photograph 1– Green River Ferry Road North showing typical road section

Photograph 2– Green River Ferry South core from 1 to 3-foot depth with road base over silty sand

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Appendix B – Photos of Green River Ferry Ramp

Photograph 3– Green River Ferry South Ramp core showing 8-inch slab thickness cc: Pavement (M. Elias), Highway Design (D. Hassan), Hydraulics (A. Kapoor), Environmental (L. Landers)