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The 35Express project extends 30 miles, through eight cities and two counties, from I-635 in Dallas County to US 380 in Denton County. I-35E is one of the most heavily traveled corridors in the North Texas region, and this project will relieve congestion by adding general purpose lanes, frontage roads, and a tolled reversible managed lane. The project cost is $1.4 billion. Design started in spring 2013, construction began in fall 2013, and scheduled completion is mid-2017. 

The 35Express design-build project is contracted by TxDOT with AGL Constructors responsible for design and construction. AGL Constructors is a joint venture between Archer Western Contractors, LLC, Granite Construction Inc., and The Lane Construction Co. The project design is led by a joint venture of Parsons and HDR, and Terracon is responsible for geotechnical engineering and pavement design for the project. The project included new direct connectors at SRT (SR 121) and LBJ (I-635), a new southbound bridge over Lake Lewisville, and a three-level intersection at Beltline Road.

The presentation will focus on the geotechnical aspects of the project and will describe Terracon’s overall scope of work, the field investigation, geotechnical design, key engineering concerns, and post-design services. The magnitude of the project and coordination of a large team and numerous subcontractors will be discussed. Of primary interest to other geotechnical professionals will be unique aspects of design and construction that Terracon’s team implemented to provide improved design and construction processes, and lessons learned over the course of design and construction.

More information about the project is available online at 35express.org

Liz Smith has 30 years of experience in geotechnical engineering and specializes in geotechnical engineering for bridges and highway projects. She is a Senior Principal at Terracon (10 years at Terracon) and has a BS and MS in Civil Engineering from Virginia Tech, with a specialty in geotechnical engineering. She has expertise in geotechnical design for highway structures (bridges, walls, slopes) and has worked on design-build projects since 1991 and has successfully managed complex geotechnical design-build projects with geotechnical fees over $7.5 million. She is registered PE in 11 states, licensed Geotechnical Engineer in California, and Diplomate in Geotechnical Engineering as awarded by the Academy of Geo-Professionals. Ms. Smith has been the geotechnical engineer of record on projects and major pursuits in Texas, Missouri, New Mexico, California, Washington, Arizona, Minnesota, and Hawaii. She is active in professional organizations including TRB, DFI, DBIA, ASCE GeoInstitute, ADSC, and WTS (Women's Transportation Seminar, former president of the WTS Austin chapter). She was elected to the Virginia Tech Civil and Environmental Engineering Academy of Distinguished Alumni in 2015. She is married 31 years to husband Jack Smith and they have three adult sons. 

Applications in Geo-Structural Design: A Contractor's Perspective

In today’s Design-Build Construction environment, Architects and Engineers are turning to contractors to provide alternatives to handle unique soil-structure interaction challenges. The specialty foundation contractor has become one of their best partners in developing competent, cost effective solutions to many of these types of problems. This presentation will focus on the relationship between project designers and experienced contractors, as well as a few examples of how design-build projects can best achieve their desired outcomes. In addition, the roles and responsibilities of both the geotechnical engineer and the contractor with respect to design liability will be discussed. 

As a project manager and geo-structural design engineer, Mr. Edens has managed and performed Design-Build projects over the past 27 years for state DOT’s, FHWA, US Army Corps of Engineers, large commercial clients, general contractors, and specialty foundation contractors. His experience includes the design, marketing and sales of earth retention systems, landslide remediation systems and foundation support systems, including soldier beam/wood lagging walls, Mechanically Stabilized Earth Walls, concrete caisson walls, slurry and concrete diaphragm walls, soil nail and tieback systems, jet grouting, compaction grouting, micropiles, caissons, deep soil mixing, displacement piles and aggregate piers. He now serves as a Senior Design Engineer with Hayward Baker Inc., the nation’s largest design-build foundation contractor.