A significant project design element included structural design of the terminal building’s foundation system to span the existing City of Los Angeles Central Outfall Sewer (COS), a brick and mortar sewer pipeline constructed in the late 1930’s that crosses diagonally beneath the building.  This project has received an ENR California “Award of Merit” in the Airport/Transit – Southern California category.

Project Highlights:

  • Geotechnical Engineering
  • Geotechnical Observation and Testing
  • 5-Story Terminal Building

Ninyo & Moore provided geotechnical services for the design and construction of Southwest Airlines’ new Terminal 1.5 at Los Angeles International Airport (LAX). The new terminal has a footprint of approximately 52,000 square feet and consists of a five-story structure, including four above-grade levels and one basement level. The new structure connects Terminals 1 and 2, which were previously separated by an undeveloped, open-space area. The new structure is supported by a combination of shallow and deep foundations consisting of a combination of over 300 concrete cast-in-drilled hole (CIDH) and torque-down piles. Piles adjacent to the COS were deepened and constructed with steel sleeves around their upper portions to transfer new building loads beneath the COS. Zero lot line construction required special attention during design, and underpinning of portions of the existing structures, to see that new building loads and construction would not impact existing terminal buildings. The project included the removal and reconstruction of a new approximately 375-foot-long by 20-foot-high retaining wall along the north side of the lowest floor to account for ground elevation differences on each side of the building. The retaining wall excavation and building excavations, including the basement, extended to depths of up to approximately 44 feet and required the use of temporary shoring. The shoring consisted of 122 soldier piles with wood lagging and up to two rows of tie-back anchors (122 anchors). Other site work included construction of temporary crane pads, design of a temporary pad to bridge construction loads over the COS, construction of new aircraft pavements, and installation of new utilities.

Project Details


Southwest Airlines c/o PGAL


Los Angeles, California



Clients of Ninyo & Moore receive the services of professional geotechnical engineers and engineering geologists that are familiar...


Clients turn to Ninyo & Moore environmental consultants for innovative solutions to complex environmental challenges.

Materials Testing and Inspection

Our Materials Testing Division provides full-scope soils, materials testing, and special inspection services utilizing...



Administratively Qualified (AQ) with TxDOT

Ninyo & Moore is pleased to announce that we are now Administratively Qualified (AQ) with TxDOT.

Learn More


Engineering News-Record (ENR) ranks Ninyo & Moore No. 3 Geotechnical Engineering Firm and No. 192 Overall


Learn More

Featured Projects


© Los Angeles County Metropolitan Transportation Authority - Regional Connector Transit Project

Metro Regional Connector

Career Opportunities

Collaborate with industry experts who are passionate about making a positive impact on the environment around us.

Join our team!

Learn More

Social Media


We are committed to a safe workplace.

Learn More


Continuing to deliver new engineering advances so our clients receive superior results.

Learn More


Seamless integration of technical and project management experts so you achieve predictable and successful results.

Learn More

NINYO & MOORE We transform today so our world is a better place tomorrow.