UT FTFW OURA 11-1 Auto Tour Route - V1 PM tech memo rev. 07-10-19a.pdf

Subject: Final Pavement & Materials Recommendations UT FTFW OURA 11(1) Auto Tour Route

From: Marty Fey Pavement & Materials Engineer, CFLHD

To: Braden Peters, Project Manager, CFLHD

INTRODUCTION

This memorandum provides revised material recommendations for the Ouray National Wildlife Refuge Auto Tour Route project near Ouray, UT. The project consists of widening, rerouting, and resurfacing existing aggregate surfaced road RTE 011 within Ouray NWR. CFLHD standards and guidelines were used to complete the materials recommendations.

FIELD INVESTIGATION

On October 3rd, 2018 CFLHD pavement & material staff completed a field investigation which included sampling with the hand auger. The depth of sampling was limited due to gravel and cobbles in the sampled material.

A return visit was made on June 25th, 2019 to sample from a roadbase stockpile at the KW Crushing pit on SH 88 North of 5500 S in Ouray UT. This source is currently being used by the refuge for repairs to their roadways and is preferred due to its close proximity and native aesthetic.

The primary objectives of this field investigation were as follows:

Measure and record existing subgrade layer depths;

Gather subgrade soil samples for follow-up testing to determine engineering properties;

Evaluate roadway and project area for constructability concerns.

The information gathered as described above was used to support pavement rehabilitation, structural design, and material recommendations.

Below are summary tables of data gathered and test results. For more complete and detailed results, see the attached lab test reports.

Technical Memorandum

Date: January 14, 2019 Rev: July 10, 2019

SAMPLING AND TEST RESULTS

Currently there is a surface layer of granular roadbase ranging from 6 to 8 inches in thickness.

The material is reddish brown in color, contains fractured aggregates, and is classified as SM / A-1-b(0). This material appears to provide good structural support and is performing well.

We were unable to sample beneath the roadbase layer due to gravel and cobbles making it difficult to hand auger. Material obtained from the source stockpile had a similar appearance, gradation, and classification. The stockpiled material was found to have an R-Value of 70.

We also sampled ‘native’ or pit run material from unimproved RTE 045. This material is grey in color with rounded aggregates. It is classified as SM / A-2-4(0).

For more complete and detailed results, see the attached lab test reports.

TRAFFIC

NWR personnel and observations at the site indicate traffic levels are low with less than 20 visitors per day. The route will also see an occasional school bus and little to no heavy truck traffic. Existing aggregate roadway is generally performing well.

DESIGN RECOMMENDATION

Resurfacing Sections Layer Thickness

Aggregate Surface Course 4 inches Existing Subbase (Reconditioned) 6 inches

Realignment Sections Layer Thickness

Aggregate Surface Course 8 inches

ADDITIONAL RECOMMENDATIONS

Include a nominal amount of subexcavation (~500 cu yd) to be used at discretion of CO.

Recommend the following bid items.

Item Number Item Description Unit 20402-0000 Subexcavation CUYD 30110-0000 Aggregate Surface Course TON 30301-5000 Aggregate Surface Reconditioning MILE

Attachments:

Lab Test Reports