Artist rendering of the "Rock Shed"
July 20, 2016 - Caltrans has issued a statement on the status of the Highway 140 Ferguson Slide Permanent Restoration Project in Mariposa County.
Caltrans reports the following:
There were significant rockslides and we are assessing the area.
Originally, construction on the rock shed was scheduled to start in spring/ summer 2016.
Caltrans was hoping to start construction on the “rock shed” in March 2016 (if weather permitted); however, during the winter suspension of the project there were significant rockslides in November and December 2015.
The first significant rockslide occurred around the early morning of November 18, 2015.
The Caltrans Office of Geotechnical Services assessed the area on Thursday, November 19, 2015, and made a preliminary assessment that the rockslide was significant and more assessment was needed.
The second significant rockslide occurred around the early morning of December 21, 2015.
No one was injured during the rockslides.
The rockslides did not impact traffic because motorists have been using a temporary bridge since 2008 that is several feet away from the slide.
An independent consultant (Wyllie & Norrish Rock Engineers) was hired in January 2016 to assess the slide and provide Caltrans with a second opinion.
Caltrans is currently waiting for a report from Wyllie & Norrish Rock Engineers.
In order to collect the necessary data, four 250-feet deep boreholes will be strategically placed on the slope.
Environmental permits are currently being processed for this work.
Work to install the boreholes is expected to occur from August 2016 to November 2016, contingent upon weather, obtaining permits and equipment availability.
Caltrans was hoping to install the boreholes once weather permitted but the department needed to obtain new environmental permits from other agencies (i.e. Fish and Game).
Geotechnical data on groundwater elevations and slope stability is expected to be collected from November 1, 2016 to March 1, 2017, contingent upon weather, permits and equipment availability.
The final assessment and report is estimated to be completed by early fall 2017 with the cooperation of Mother Nature.
Due to the construction delay, the California Transportation Commission (CTC) approved to move the federal funding set aside for this project to other projects in the State that are ready for construction.
The decision was finalized at the June 2016 CTC meeting.
When the Ferguson Project is ready for construction, the funds will be re-programmed.
Source: Caltrans
