U.S. Highway 50 Fresh Pond Slipout Repair Project

PROJECT DESCRIPTION:

The project was initiated as a permanent restoration to the roadway sink at the location that occurred in February 2017. This project is located on U.S. Highway 50 (US 50) in El Dorado County near Fresh Pond, about 0.4 miles west of the US 50 and Forest Road intersection. 

The roadway is a three-lane conventional highway for 0.3 miles and transitions to a two-lane conventional highway to the east toward Echo Summit and four-lane expressway to the west toward Sly Park.

PURPOSE AND NEED:

Purpose

The purpose of this project is to permanently restore the roadway to a safe riding condition and mitigate the progression of the reoccurring roadway slip-out failure by building a 425-foot long by 55-foot tall retaining wall and permanent concrete barrier along the westbound section of the highway.

Need

On February 14, 2017, a roadway slip-out incident occurred at the project location. The slip-out covered about 300 feet along the alignment and the entire roadway cross-section. It was observed that the roadway cracked on both the eastbound and westbound (WB) lanes and a differential settlement of up to 5 inches was recorded on the westbound lane. There was also sagging of the metal beam guardrail on the WB lane. A temporary restoration project was initiated to restore the pavement to drivable condition and perform geotechnical explorations. After asphalt concrete (AC) pavement reconstruction activities were completed, additional AC pavement cracking and differential settlement resurfaced within a month.

The location on US 50 has a history of significant surface cracking and continual sinking. The roadway is bounded by steep fill slope to the north and very steep cut slope to the south. The original embankment was built up to about 150 feet high from the old US 50 under stage sequenced construction. The materials used were loose and rocky and the soil was inadequately compacted. Below the roadway surface, there is occurrence of differential ground movement that may also have been aggravated by high ground water seepage from the cut slope section into the fill.

To maintain public safety and ride quality, Caltrans maintenance division have been applying several blankets of AC on the roadway surface over the years. This project is therefore needed to provide a permanent solution to this reoccurring roadway failure.

FUNDING:

This project will be fully funded under the 2018 State Highway Operation and Protection Program Amendment – Major Damage (Permanent Restoration - 201.131) program. This project is eligible for federal-aid funding.

COST ESTIMATE:

Support Cost: $6,554,000
Capital Cost: $12,530,000
Total Project Cost: $19,084,000

SCHEDULE:

Project Approval, Environmental Document: 3/24/2019
Design Completed: /01/31/2020
Advertise Project: 03/23/2020
Begin Construction: 9/25/2020
Complete Construction: 04/15/2022

PROJECT CONTACTS:

Martin Clark, Project Manager, (530) 682-6333; martin.clark@dot.ca.gov
Steve Nelson, Public Information Officer, (530) 741-4566; steve.nelson@dot.ca.gov