The project schedule has been revised for project completion in mid-November. The schedule revision is due to several factors. More rock was encountered during the pile drilling operations than anticipated and additional drainage improvements are being installed on the uphill side to address future rain runoff from the hill above the project site. The temporary access road will remain open until project completion.
The contractor started work in mid-July after utilities were relocated out of the project area. Since mid-July, the contractor completed the following:
- Removal of approximately 30 trees and vegetation from the project site area.
- Removal of the full width of pavement within the project area.
- Placement of approximately 6 feet of fill material over the entire roadway along the length of the uphill wall in order to accommodate the pile drilling operation for the uphill retaining wall.
- Installed 32 soldier steel piles which are the foundation for the uphill retaining wall.
- Excavated the site to 4 feet below the future finished grade of the roadway to begin the drilling of the horizontal soil anchors between the steel soldier piles. The soil anchors are part of a retaining system that holds the large mass of slide material in place.
- Installed 30 soil anchors placed at each of the double steel I beams locations excluding the last soldier pile at each end of the wall. Each soil anchor is comprised of a bundle of steel tendons placed within a 6” drilled hole extending 60 feet horizontally from the face of the wall.
- Installed the concrete lagging for the uphill retaining wall to a maximum height of 15 feet.
- Started drilling the foundation piles for the downslope retaining wall. The downhill retaining wall includes the installation of 36 inch diameter cast-in-drilled-hole reinforced concrete piles to depth of approximately 57 feet (total of 36 piles). As of the end of the day on September 18, the contractor installed 14 of the 36 piles.
Once the downslope retaining wall is completed, the contractor will excavate the soil between the two retaining walls system to a depth of 10 feet, install subsurface drainage and reinstall (i.e., compact) the soil in place; install the new waterline (approximately 600 feet) including tie-in and disinfectant work; reconstruct the pavement between the two walls; install drainage improvements including additional concrete swale at top of uphill retaining wall; install concrete barriers (both sides of the roadway), install metal beam guard railing; install hand railings and cable railings; install fencing; install pavement striping; and paint/stain exposed faces of steel beams, railings and barriers.
We will continue to communicate project updates.