Virtual S3 2020: Slopes, Slides and Stabilization This year’s conference, originally slated for August 4-6, 2020, in San Francisco, is being held as a webinar on August 5, 2020, due to the inability to gather during the COVID-19 pandemic. The webinar serves as the fourth installment in DFI’s Software Discussion series which is usually live- streamed from DFI’s S3: Slopes, Slides and Stabilization Conferences. The event on August 5, from 11:00 a.m. to 3:00 p.m EDT, features live presen- tations on software analysis followed by a panel discussion. This discussion series was developed to further industry under- standing of the use of software for slope stabilization problems. Providers of commonly used software packages will discuss, analyze and present solutions for a real-world slope stabilization problem, discuss how the software was used to prepare various solutions, and provide tips on using packages to produce and validate solutions. The presentation will be fol- lowed by a facilitated Q&A discussion. Ben Turner, Ph.D., P.E., of Dan Brown and Associates, leads off the software discussion wi th his presentat ion, “Incorporating Deep Foundations in Limit- Equilibrium Slope Stability Analyses: Revisiting Fundamentals and Seismic Applications.” Deep foun-dations are commonly used to prevent or stabilize existing landslides, deriving resistance to slope movement through embedment in bearing material below the slide plane. A variety of design methods are used in practice to incorporate piles into limit- equilibrium method slope stability analysis, some of which fail to adequately capture the pile resistance mechanism or correctly identify the critical pile failure mode, leading to false interpretation of factors of safety. Of particular concern is the common practice of assigning the shear strength of the pile material, e.g., the shear strength of concrete or steel multiplied by the cross sectional area of the pile, as a resisting force in slope stability analyses. Without performing separate laterally loaded pile analyses, this approach fails to identify whether shear failure is in fact the controlling pile mechanism; more often than not, analyses show that the pile would actually fail in flexure prior to shear. As a result, the shear strength approach may drastically overestimate the pile contri- bution to stability, inflating the calculated factor of safety. The following providers will analyze the problem using a variety of methods, present solutions and engage the audience in a detailed Q&A session: • Bentley/Soilvision/Plaxis • GEOSTASE • Itasca • Rocscience Next year, S3 2021: Slopes, Slides and Stabilization is being held by DFI at the Hotel Kabuki in San Francisco from August 3-5, 2021. Cooperating Organizations Federal Highway Administration International Society for Micropiles Pile Driving Contractors Association Media Partner PileBuck www.dfi.org/S3-2020 DEEP FOUNDATIONS • MAY/JUNE 2020 • 37
