New DFI Publications Available Diaphragm Walls as Permanent Basement Walls in Regions of High Seismicity Authors: Charles B. Grant, P.E., S.E.; Dominic J. Kelly, P.E., S.E.; Michael P. Walker, P.E. Reinforced concrete structural slurry walls have been used in the United States since the early 1960s. The typical practice, and one that makes the economics of slurry walls particularly attractive, is to design the walls to act as both temporary excavation support and permanent basement walls. They often serve as multistory basements and below-grade parking for buildings, tunnels, subway stations and other buried structures. One of the early applications was for a foundation for a subway station in San Francisco, but for the most part they have been used more extensively in regions of low seismicity. The purpose of this report is to investigate the requirements for extension of this practice to more common use in regions of high seismicity. Effect of Coupling on A-Walls for Slope Stabilization Authors: Andrew Boeckmann, P.E.; J. Erik Loehr, Ph.D., P.E.; Helen Robinson, P.E.; Minh Uong; and Jesús Gómez, Ph.D., P.E., DGEP A-Walls have been used successfully for slope stabilization. Methods are developed for predicting the resisting forces in A- Walls for slope stabilization based on results of full-scale field installations of A-Walls, and experimental results involving scaled micropile elements installed in large-scale physical models. This is a significant development since the method satisfies compatibility between mobilization of axial and lateral load transfer, which have been observed to mobilize at substantially different rates. Although the method satisfies compatibility, it does so with uncoupled (i.e., separate) lateral and axial analyses, without consideration of interaction between upslope and downslope micropiles (which are connected through a capping beam). This potentially produces errors in predictions of reinforcement forces, which in turn could have a notable effect on slope stability. To evaluate the effect of coupling, the research team analyzed slopes stabilized with A-Walls using a finite element model with upslope and downslope piles connected at the pile head. This report includes design impl icat ions resul t ing from the coupl ing effect and recommendations for further research. Development of a Design Guideline for Bridge Pile Foundations Subjected to Liquefaction-induced Lateral Spreading Authors: Jonathan Nasr and Arash Khosravifar, Ph.D., P.E. Effective-stress nonlinear dynamic analyses (NDA) were performed for piles in liquefiable sloped ground to assess how inertia and liquefaction-induced lateral spreading combine in long-duration vs. short-duration earthquakes. A parametric study was performed using input motions from subduction and crustal earthquakes covering a wide range of earthquake durations. The NDA results were used to evaluate the accuracy of the equivalent static analysis DEEP FOUNDATIONS • NOV/DEC 2018 • 55 (ESA) recommended by Caltrans/ODOT for estimating pile demands. Finally, the NDA results were used to develop new ESA methods to combine inertial and lateral spreading loads for estimating elastic and inelastic pile demands. Project Information Management Systems in the Deep Foundations Industry White Paper DFI Project Information Management Systems (PIMS) Committee; Vanessa Bateman, P.G., P.E.; Massimo Mucci; Mark Petersen, P.E., G.E.; and Jamey Rosen, P. Geo. This document provides a general introduction to the concepts and applications of a Project Information Management System (PIMS) to the geotechnical foundations industry. While geotechnical projects have always generated data and created related visualizations and analyses, in the past decade the industry has seen an increase in specifications and owner requirements for formal data management and associated project submissions. At the same time, new and adapted technologies are emerging (the nature and rate of adoption of these differ across regions and owners) that allow increased automation and greater digitalization and generation of data in increasing volumes. The DFI PIMS Committee was formed to guide the industry in navigating these trends and provide tools to DFI members to maximize the benefits from information management. This document was written by the DFI PIMS committee to provide some nontechnical guidance to the industry on these concepts Download for FREE at www.dfi.org/publications.asp?cat=cpf
