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INSTRUCTORS: 
Mike G. Gomez, Ph.D.
Lisheng Shao, Ph.D., P.E., G.E.
Jim Gingery, Ph.D., P.E., G.E.
Mohammad Khosravi, Ph.D.
Joseph Sopko, Ph.D., P.E.

Course Length: 2 hours

Purpose and Background

This course will only award PDHs for completion.

 Mitigation of Earthquake-induced Soil Liquefaction (20 minutes)

This presentation discusses the use of biocementation, specifically microbially-induced calcite precipitation (MICP), to transform loose granular soils into stiffer, stronger, rock-like materials. The process involves a series of biochemical reactions that result in the precipitation of calcium carbonate, significantly improving soil's shear stiffness and strength. The talk highlights the environmental and cost benefits of this bio geotechnical approach compared to traditional methods. The effectiveness of MICP in liquefaction mitigation is demonstrated through lab testing and field applications.

Time Effects of CPT-Based Evaluations for Liquefaction Mitigation by Vibro Stone Columns (14 minutes)

This presentation covers a case study on the time effects observed in CPT-based evaluations after implementing stone column treatments for liquefaction mitigation. Stone columns densify surrounding granular soils through cyclic shear and backfilling with gravel, enhancing soil stability. The study focuses on time series data collected before, during, and several months after treatment, showing the progressive improvement in soil strength and reduction in liquefaction potential. The presentation underscores the longevity and effectiveness of stone columns in densifying soil and mitigating liquefaction risks​.

Modeling Vertical Reinforcing Effects of Columnar Ground Improvement for Post-Liquefaction Settlement Mitigation (20 minutes)

This presentation addresses the modeling of vertical reinforcing effects using columnar ground improvement techniques to mitigate post-liquefaction settlements. It emphasizes the importance of considering volumetric strain in practical design and how ground improvement methods like Ishihara and Yoshimini's techniques are adapted for these conditions. The presentation contrasts free field settlement with the enhanced conditions provided by vertical reinforcements, showing significant reductions in settlement due to the reinforcement. Various modeling approaches, including TM4SAN and composite modulus methods, are discussed for their applicability in practical designs.

Reinforcing Mechanisms of Soil-Cement Columns in Liquefiable Sand Under Embankment and Earthquake Loading (20 minutes)

This presentation explores the reinforcing mechanisms of soil-cement columns when applied to liquefiable sands, particularly under conditions of embankment and earthquake loading. The talk delves into how soil-cement columns provide both immediate and long-term stabilization through increased shear strength and stiffness. Laboratory and field tests demonstrate the columns' effectiveness in preventing liquefaction and enhancing the structural integrity of embankments. The research also highlights the benefits of combining soil-cement columns with other ground improvement techniques for comprehensive liquefaction mitigation​.

Ground Freezing Standardization for Ground Improvement (20 minutes)

This presentation discusses the standardization of ground freezing techniques for ground improvement, based on the insights from the International Symposium on Ground Freezing. The discussion covers the development of standardized site investigation methods for ground freezing applications, emphasizing the need for detailed geotechnical investigations and appropriate laboratory tests. Ground freezing is presented as a reliable method for temporary excavation support and groundwater control, particularly in saturated zones. The presentation also touches on practical challenges and solutions in implementing ground freezing in various soil conditions, highlighting successful case studies.

Learning outcomes and session benefits

Upon completion of this course, you will be able to:

• Identify existing and novel ground improvements for liquefaction mitigation and ground stabilization.
• Explain new analytical techniques and interpretation methods for cost-effective assessment of ground improvement alternatives.
• Assess and select available types of equipment and techniques for liquefiable soils.
• Identify creative solutions for clients to complex subsurface challenges in seismic environments.

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?

• Geotechnical Engineers
• Engineering Geologists
• Owners and Operators of Civil Infrastructure
• Consultants
• Public Agency Engineers
• Specialty Contractors

How to Earn your PDHs and Receive Your Certificate of Completion

This course is worth 0.2 CEUs. 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.