Determining the Fill Depth Before Construction
A drilling rig was working on the large vacant lot at 1525 Palisades Drive on Tuesday. Located at the edge of the property, the borer went down time after time and brought up dirt.
Neighbors told Circling the News they are worried that construction of the proposed four-story eldercare facility (including a two-level subterranean parking structure and swimming pool) is now underway on the 43,033.2-sq.-ft. lot. Many neighbors have fought the development, first through the City Planning Department (which approved the project) and then the California Coastal Commission. A lawsuit was filed and is waiting resolution.
Opponents were told by City officials that if the developers, Rony and Moshe Shram, obtained the needed permits from the Department of Building and Safety, they could build the whole facility while the lawsuit is pending. But if the Shrams lose, they could risk losing their entire construction investment.
The Shrams hired a new geotechnical firm, SASSAN Geosciences, which sent a new report to the city grading division, dated November 27, 2018.
In that report, it was noted that the property had remained unchanged, but that “the description of the proposed development has changed.” The new report provided “revised recommendations for design and construction of the proposed structure, based on current architectural plans.”
It stated that retaining walls up to 23 feet in height would need to be constructed and “excavations up to 23 feet in depth would be required during construction of the proposed subterranean parking.”
The November report noted that based on previous investigations, the existing fill is about 36 feet deep, but “based on the previous cross-sections the thickness of the fill at the outer edges of the pad may be thicker.”
CTN contacted SASSAN Geosciences by email on February 27 and president Sassan Salehipour responded immediately.
He confirmed that the current drilling is to determine how deep the fill is at the edges of the property—nearest the City park.
In the report, the fill depth was listed as 36 feet deep, and Salehipour was asked if that was the depth for the whole property. He wrote, “No. We are trying to determine the fill depth by additional drilling.”
Salehipour was asked if all the fill would have to be removed from the site and he said, “No.”
The depth of the fill is important for two reasons: shoring and hauling.
Under shoring design recommendations, the first item listed is “Soldier piles of the shoring system must be founded at a minimum depth of eight feet into bedrock.”
SASSAN’s detailed and specific report includes foundations (conventional footings and friction pile foundations), sub-drain systems, seismic parameters, settlements, engineered fill and internal concrete slabs.
As far as the fill, hauling becomes a central issue.
An initial report from the developer stated that about 19,300 cubic yards of soil would need to be transported down Palisades Drive. If for argument’s sake only 30,000 sq. ft. of the lot is excavated to 23 ft., that would mean about 25,550 cubic yards of dirt would need to be removed. If a dump truck can hold 11 cubic yards, that would mean 2,323 truck trips.
A May 15, 2017 Geology and Soils Report Approval Letter, prepared by L.A. City engineers Casey Lee Jensen and Ying Liu, noted that the lot is located at the top of an about 100-ft. high 2:1 fill slope and “the earth materials at the subsurface exploration locations consist of up to 50 feet of uncertified fill underlain by silty sandy clay residual soil and Sespe Formation semi-friable sandstone, conglomerate and some thin layers of claystone bedrock. (Visit: documents.coastal.ca.gov/reports/2018/7/w15c/w15c-7-2018-exhibits.pdf).
(Editor’s note: After the eldercare project was approved by the City Planning Department, it was appealed on April 25 to the West Los Angeles Area Planning Commission. Highlands residents complained about the project’s lack of setbacks, possible increased traffic and its location in a City-designated High Severity Fire Hazard Zone. The appeal was denied, and residents then appealed to the State’s Coastal Commission and the appeal was denied. A lawsuit by PPRA (Pacific Palisades Residents Association) was filed against the City and the California Coastal Commission. Look for a future story about the Coastal Commission hearing regarding 1525 Palisades Dr.)