Los Angeles International Airport (LAX) Terminal 1.5, CA
Ninyo & Moore, a SOCOTEC Company, provided geotechnical engineering services for the design and construction of the new $490M LAX Terminal 1.5, one of the most complex airport infrastructure projects in Southern California — and a critical component of Los Angeles's preparation for the 2028 Olympic Games.
Key Information
Project Name: Los Angeles International Airport – Terminal 1.5
Client: Los Angeles World Airports (LAWA)
Location: Los Angeles, California
Services Provided: Geotechnical Engineering
Award: ACEC California Honor Award; ENR California – Award of Merit (Airport/Transit, Southern California)
Talk to our experts
The Challenge
Connecting Two Terminals Over a Century-Old Underground Sewer
LAX Terminals 1 and 2 had remained separated since Terminal 1 was originally constructed in 1984 in preparation for the 1984 Olympic Games. The open space between them exists because the City of Los Angeles Central Outfall Sewer (COS), an active underground brick-and-mortar pipeline built in the late 1930s, runs directly through this area.
As Los Angeles prepares to host the 2028 Olympic Games, the Landside Access Modernization Program (LAMP) required that Terminals 1 and 2 be connected to improve passenger access and movement throughout LAX.
The project involved the construction of a new five-story structure, with four above-grade levels and one basement level, with a footprint of approximately 52,000 square feet, located directly above and adjacent to the existing COS.
The structure accommodates multiple critical airport functions, including baggage claim and ticketing lobbies, Federal security checkpoint, airside connector, retail concessions and leasable office space, bus gate and outbound baggage system (including CBIS), inbound baggage system and vertical circulation core connecting to the future Automated People Mover (APM).
Building directly above and adjacent to the existing COS presented significant geotechnical and structural challenges, including:
Designing foundations that transfer new building loads beneath the COS without impacting the existing pipeline
Zero lot line construction requiring special attention to prevent impacts on existing terminal buildings
Underpinning portions of existing structures during construction
Coordinating deep foundation design in a highly constrained active airport environment
The Solution
Advanced Geotechnical Engineering for a Complex Urban Airport Structure
Ninyo & Moore, a SOCOTEC Company, delivered comprehensive geotechnical engineering services for both the design and construction phases of Terminal 1.5.
Geotechnical Engineering & Foundation Design
- Geotechnical engineering for the design of the terminal structure
- Foundation system design (shallow and deep foundations)
- Engineering solutions to span the existing Central Outfall Sewer (COS)
- Specialized pile design, including concrete cast-in-drilled-hole (CIDH) piles, torque-down piles, and deepened piles with steel sleeves near the COS
- Design considerations for zero lot line construction
- Underpinning design to protect adjacent existing structures
Excavation, Shoring & Earth Retention Systems
- Design and observation of deep excavations (up to ~44 feet)
- Temporary shoring systems, including soldier piles with wood lagging and tie-back anchors
- Removal and reconstruction of a retaining wall (~375 ft long, ~20 ft high)
- Engineering support for grade differences across the site
Construction Support, Observation & Site Works
- Geotechnical observation and field-testing during construction
- Design of temporary works, including crane pads and temporary load transfer platform over the COS
- Geotechnical support for aircraft pavement construction
- Geotechnical input for installation of new utilities
Ninyo & Moore, a SOCOTEC Company, delivered comprehensive geotechnical engineering services for both the design and construction phases of Terminal 1.5.
Geotechnical Engineering & Foundation Design
- Geotechnical engineering for the design of the terminal structure
- Foundation system design (shallow and deep foundations)
- Engineering solutions to span the existing Central Outfall Sewer (COS)
- Specialized pile design, including concrete cast-in-drilled-hole (CIDH) piles, torque-down piles, and deepened piles with steel sleeves near the COS
- Design considerations for zero lot line construction
- Underpinning design to protect adjacent existing structures
Excavation, Shoring & Earth Retention Systems
- Design and observation of deep excavations (up to ~44 feet)
- Temporary shoring systems, including soldier piles with wood lagging and tie-back anchors
- Removal and reconstruction of a retaining wall (~375 ft long, ~20 ft high)
- Engineering support for grade differences across the site
Construction Support, Observation & Site Works
- Geotechnical observation and field-testing during construction
- Design of temporary works, including crane pads and temporary load transfer platform over the COS
- Geotechnical support for aircraft pavement construction
- Geotechnical input for installation of new utilities
The Results
A Critical Connection for LAX and the 2028 Olympic Games
Through expert geotechnical engineering, Ninyo & Moore, a SOCOTEC Company, supported the successful delivery of a landmark terminal that transforms passenger experience and operational efficiency at LAX.
Key Outcomes:
Seamless connection between Terminals 1 and 2 for the first time in LAX history
Uninterrupted link between ticketing and baggage claim lobbies of both terminals
Enhanced operational flexibility for the airport and airlines
Safe foundation design preserving the integrity of the 1930s Central Outfall Sewer
Critical infrastructure ready for the 2028 Los Angeles Olympic Games
Recognition with the ACEC California Honor Award – 2022 Engineering Excellence Award
Working on an airport or public infrastructure project?
.
