Admiralty Way Ground Improvement Case Study: Fid-Bau Portal

Admiralty Way Ground Improvement Case Study

D'Antonio, Rossana Genise / Lay, Garry / Wan, Jeremy / Su, Neville / Cruz, Olga / Shao, Lisheng

Admiralty Way is located in Marina Del Rey, Los Angeles County, California. Built on a former landfill known as the Venice Dump, operational during the early to mid-1900s but currently closed, the roadway has been subjected to continuous consolidation of the underlying materials. The subsurface materials consist of an artificial fill layer underlain by layers of soft to very stiff clayey soils. The artificial fill layer is composed predominantly of loose to medium dense silty-sand, clayey-sand, and soft to medium stiff silty-clay with varying amounts of debris such as glass, asphalt, brick, wood, metal, and other foreign matter. As the voids developed in the artificial fill, the site has suffered considerable settlement. The asphalt concrete paving suffered surface dips and bumps even after several resurfacing treatments throughout the years. Compounding the already complex site conditions were high traffic volumes and potential contaminated soils ruling out the traditional remedial measures. Remediation selected was in situ ground improvement using compaction grouting techniques to mitigate the ongoing roadway embankment settlement and deformation. The improvement scheme generally consisted of primary, secondary, and reinforced compaction grouting to a depth of 4.6 meters (15 feet) below existing pavement subgrade. Upon completion of ground improvement, 15-centimeters (6-inches) of existing asphalt concrete were removed via cold milling and stockpiled offsite. Millings were mixed with an engineered emulsion and cement to produce cold central plant recycled asphalt concrete, which was placed on roadway to meet desired grade and subsequently capped with slurry seal.