Here's how Caltrans is shoring up Hwy. 41 hillside after the rockslide
In an arduous process that will take at least another month, Caltrans crews have so far cleared about 5,000 cubic yards of dirt and rock from Highway 41 since a mudslide closed the road Jan. 6.
The original slide, which happened on a Friday evening, was made up of about 2,000 cubic yards of material, according to Caltrans geotechnical engineer Ryan Turner. The slide was so strong that it ripped out the mesh netting that was over the 100-foot hillside to catch small rockslides. Slides at the site are usually about 100 cubic yards.
When authorities went out to assess the slide Jan. 7, they saw that the hillside had grown top-heavy with dirt and rocks — with nothing to support the weight.
“It was very apparent that that material had to come out for the highway to be safe,” Turner said Wednesday.
Caltrans crews are using a machine called a spider to scoop out loose dirt and rock from the top of the hillside.
This process will take out the unstable dirt and rock that could slide down to the road. One of the rocks that had fallen was so large that crews couldn’t lift it with a front-end loader, though they could push it around.
Jeff Scardine, a Caltrans geotechnical technician, said the agency is estimating between 15,000 and 25,000 cubic yards of material will ultimately need to be removed from the hillside.
To put that in context, a dump truck holds 15 cubic yards of material. That means if the total amount ends up being 25,000 cubic yards, Caltrans will need to remove more than 1,600 loads of dirt and rock.
Turner said material from the original mudslide was stored on various locations up and down Highway 41, and the agency will try to keep most of the material from this project as close to the site of the slide as possible. Below the road, there is a bench of land where Caltrans plans to store some of the dirt and rock.
With more rain expected to hit the Central Coast in the coming days, Turner said keeping workers safe will be the top priority.
“We’ll work as long as it’s safe,” he said, adding that an exact finish date is “out of our hands.”
The highway is expected to remain closed until mid-February, and the project is expected to cost $1.5 million.