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INSTRUCTORS: 
Ke Yang, Ph.D., P.E.
Eric Brichler
Andrew Moran, P.E.
Chu E. Ho Sc.D., D.I.C.
Joanna Mason, P.E.

Course Length: 1.5 hours

Purpose and Background

These presentations were recorded at the 2024 Geo-Structures Conference.

An Innovative Micropile Support of Excavation System to Meet Challenging Site Constraints (19 minutes)

This presentation highlights a groundbreaking approach to excavation support, using micropiles as vertical elements for a soldier pile and lagging wall system. It was developed to address stringent site constraints—including restricted equipment, limited space, and stringent vibration controls—this solution ensures watertight performance while protecting adjacent structures. The presentation explores design iterations, construction challenges, and lessons learned from integrating micropiles with steel sheets for groundwater cutoff and stability.

Shoreline Storage Tunnel Shafts and Near Surface Structures Support Excavation (19 minutes)

This presentation explores the development of support systems for large-diameter tunnel shafts and near-surface structures in Cleveland, Ohio, as part of a critical infrastructure upgrade. The outlines include the application of diaphragm wall (D-wall) techniques, unreinforced concrete shafts, and innovative cement-bentonite slurry systems for cost-effective, eco-friendly excavation support. Attendees will gain insights into addressing complex subsurface conditions, water control challenges, and sustainability-focused design solutions.

Pitt Rec Center – Repurposing Existing Features for New Support of Excavation System (22 minutes)

This case study covers the adaptive reuse of existing foundation walls for the University of Pittsburgh’s new recreation center. By incorporating advanced techniques like rock bolting, shotcrete overlays, and specialty drilling, the project exemplifies cost-saving measures and reduced environmental impact. The presentation showcases structural evaluation, innovative solutions to overcome design challenges, and the integration of sustainable practices in a constrained urban setting.

Ground Loss Behind Floating Diaphragm Walls in Soft Ground Excavation (27 minutes)

The presentation explores the challenges and solutions associated with unsupported diaphragm walls in deep, soft ground. It discusses case studies, including the Second Avenue Subway in New York City, where diaphragm walls were designed to "float" without a firm base. The talk highlights settlement issues, wall deflections, and the importance of vertical stability in such designs. Using real-world data, it examines ground loss causes, including pre-construction activities, trenching effects, and dewatering. The presentation also explores the impact of wall settlement on lateral earth pressures and offers insights into mitigating ground movement. Key lessons focus on the role of vertical loads in influencing excavation behavior and ensuring stability in floating wall systems.

Design, Installation, and Performance of a 3-Sided Earth Retention System for the CoStar Campus Expansion in Downtown Richmond (13 minutes)

The expansion of the CoStar Campus in downtown Richmond required a complex three-sided earth retention system to support deep excavation for a new underground parking structure and high-rise development. This presentation details the geotechnical and structural challenges encountered, including varying subsurface conditions, historical site obstructions, and adjacent structures that required careful underpinning. The project team navigated these constraints using a combination of soldier beams, tiebacks, and an innovative soil mix pier underpinning system. Additionally, extensive monitoring and sequencing strategies ensured excavation stability while maintaining site safety and minimizing disruptions. Attendees will gain insight into best practices for urban excavation support, lessons learned from handling unexpected obstructions, and how historical site conditions can impact geotechnical design decisions. This case study highlights the importance of adaptive engineering solutions in constrained urban environments.

Benefits and Learning Outcomes

Upon completion of these sessions, you will be able to:

• Explain the design and implementation of a micropile and lagging wall system to address site constraints, including space limitations, water control, and structural protection.
• Describe the construction methods and geotechnical considerations involved in diaphragm wall shafts and cement-bentonite support of excavation systems for large tunnel projects.
• Describe the construction methods and geotechnical considerations involved in diaphragm wall shafts and cement-bentonite support of excavation systems for large tunnel projects.
• Identify the challenges of floating diaphragm walls in soft ground conditions and analyze how vertical settlement impacts lateral earth pressures and ground deformations.
• List key factors influencing the design, installation, and performance of a 3-sided earth retention system, including site geology, existing conditions, and construction sequencing

Assessment of Learning Outcomes

Learning outcomes are assessed and achieved through passing a 10 multiple choice question post-test with at least a 70%.

Who Should Attend?

• Environmental Engineers
• Geotechnical Engineers
• Structural Engineers
• Construction Engineers
• Project Managers
• General Contractors

How to Earn your PDHs and Receive Your Certificate of Completion

This course is worth 0.2 CEUs/2 PDHs. To receive your certificate of completion, you will need to complete a short on-line post-test and receive a passing score of 70% or higher within 365 days of the course purchase.

How do I convert CEUs to PDHs?

1.0 CEU = 10 PDHs [Example: 0.1 CEU = 1 PDH]