CONTENTS FEATURES Departments PRESIDENT’S MESSAGE Innovation: Share It Early and Openly . . . 7 EXECUTIVE DIRECTOR UPDATE Forward Thinking . . . . . . . . . . . . . . . . . 9 DFI ACTIVITIES Welcome to the Annual Conference; DFI’s 2019 Distinguished Service Award Winner; DFI India 9 Annual Conference on Deep Foundations Technologies for Infrastructure Development; upcoming 2020 events; and more. . . . . . . . . . . . . . . . . . . . . . . . . . 23 a recap of S3: Slope – Support – Stabilization; th REGIONAL REPORT DFI Europe . . . . . . . . . . . . . . . . . . . . . 63 EDUCATIONAL TRUST REPORT New trustee, Pennsylvania and New Jersey golf outings fundraisers, scholarship winners, professional grants announced, 2019 Trust events and recent donors . . 67 TECHNICAL ACTIVITIES UPDATE Lunch and Learn Workshop; AASHTO update; new FHWA Drilled Shaft Geotechnical Engineering Circulars; and DFI of India, DFI and Chennai Metro . . 71 GUEST EDITORIAL Motivations, Versatility and Aspirations of Professional Development Grant Winners . . . . . . . . . . . . . . . . . . . . . . 109 LEGALLY SPEAKING For Safety, the Law Makes You Your Brother’s Keeper: Understanding the Multi-Employer Worksite Doctrine . . 113 DFI PEOPLE AND COMPANIES News about people, companies and products . . . . . . . . . . . . . . . . . . . . . . 115 CALENDAR & AD INDEX . . . . . . . . 122 95 Working Platforms Jill Harris Inadequate working platforms result in accidents, stability problems and near misses by construction equipment, which could have been prevented had the working platform been designed properly and adequately maintained. Currently, in the U.S., there are no established guidelines or regulations for the design, construction and maintenance of safe working platforms. The author presents insights into the problem via discussions with industry experts. 89 A New Approach for the Design of Micropiles in Tension Sebastian Lobo-Guerrero Ph.D., P.E., and Todd DeMico, P.E. The authors present a summary of the findings from a project that incorporated tension load testing on micropiles without a continuous center reinforcing bar. The micropiles were designed using 2014 AASHTO LRFD methodology, which considered only geotechnical resistance from the side resistance within the bond zone. The results indicate that the tensile resistance of traditional micropiles (with a central bar) is typically underestimated in design. 103 The Role of Vibrating Wire Sensors in Geotechnical and Structural Monitoring Projects Tony Simmonds DEEP FOUNDATIONS The Magazine of the Deep Foundations Institute (DFI) is published bimonthly by DFI. 326 Lafayette Avenue Hawthorne, NJ 07506 USA T: (973) 423-4030 | F: (973) 423-4031 Email: [email protected] A vibrating wire sensor utilizes the electromagnetic excitation of a calibrated internal wire to provide a measurement of a given parameter being measured (e.g., strain, pressure and or temperature). As the wire is excited, the period and frequency are determined. The parameter is defined using a proportionality relationship and the square of the frequency. The author presents a wide range of applications where vibrating wire sensors were used successfully. DEEP FOUNDATIONS • SEPT/OCT 2019 • 5
