Deep foundations are designed to transfer load through unsuitable subsurface layers to suitable bearing strata. One of the key advantages of deep foundations is their ability to withstand significant lateral loads. When deep foundations are installed through a soil deposit undergoing consolidation, the resulting relative downward movement of the soil around piles induces “downdrag” forces on the piles. If embankments are placed adjacent to deep foundations, as in the case of bridge abutments, “lateral squeeze” effects can induce significant unbalanced lateral forces on deep foundations. In the case of loose collapse-susceptible soils, the moisture-induced soil collapse can have a significant lateral effect on deep foundations. Seismic events can generate lateral spread and liquefaction related ground deformations. Adjacent excavations can induce differential lateral forces on deep foundations. This workshop presents the lateral analysis of deep foundations and methods to evaluate various induced ground deformations in deep foundation designs. The presentation will be based on latest (2020) version of the Bridge Design Specifications (BDS) based on the Load and Resistance Factor Design (LRFD) platform of the American Association of State Highway and Transportation Officials which is a key component of Federal Highway Administration (FHWA) guidelines for deep foundations. Information from AASHTO’s latest (2020) guide specification for Service life design will also be presented.

Using a collaborative and interactive learning approach, this virtual workshop will help you understand: (a) principles of lateral analysis of deep foundations, and (b) the types and effects of induced ground deformations on deep foundations. The workshop will help you assimilate the crucial considerations regarding these topics through active participation by frequent interactions throughout the workshop and real-time expert feedback. The interactions will facilitate a better understanding of the nuances of the various design procedures for deep foundations which would help you avoid costly design errors in real-world projects. In between the two live sessions, attendees will independently work on an application (e.g., exercises) or a reflection (e.g., reading) assignment.

DAY 1 – Thursday,  November 17, 2022

• Loads and limit states
• Soil-structure interaction model
• Structural and geotechnical elements
• Example problem
• Equivalent cantilever model
• Steps for lateral load analysis
• Extreme Events
• Special considerations
• Review of Day 1
• Interactive Question and Answer (Q&A) session
• Assignment of homework
• Adjourn

DAY 2 – Monday,  November 21, 2022

• Roadmap for Day 2
• Review of homework
• General concepts and terminology for induced ground deformations
• Downdrag and drag load
• Moisture-induced collapse of soils
• Lateral squeeze
• Lateral spread
• Excavation-induced effects
• Summary and comments
• Closure and references
• Review of Day 2 and full workshop
• Interactive Question and Answer (Q&A) session
• Adjourn