Adobe North Tower: Innovations in Deep Foundations and Dewatering
The North Tower, located at Adobe’s global headquarters in downtown San Jose, comprises a two-level underground parking garage and an 18-story building. Malcolm Drilling was contracted to handle the temporary shoring and dewatering design and installation.
The project involved the installation of a 35,000 square foot temporary shoring wall using triple auger soil mixing equipment. The excavation averaged 30 feet, with the water table at 14 feet below grade. The shoring wall incorporated deep soil mixing, steel beams, tie-backs, and internal bracing. Some tie-backs had to be installed well below the water table and underneath city streets, as well as adjacent structures. Additionally, Malcolm installed fourteen dewatering wells, reaching depths of up to 45 feet, and ten depressurization wells, going as deep as 75 feet, to maintain the groundwater level below the excavation. The project employed automated backup pumps and wireless monitoring equipment to ensure the dewatering system maintained sufficient drawdown during all concrete work.
