Panel Discussion A lively and information-packed panel discussion of a broad spectrum of issues associated with designing and constructing was conducted at the DFI 43 Annual Conference on Deep Foundations in Anaheim, Calif. The session, Shortcomings of the Design of Electric System Founda- tions, was co-moderated by the Electric Power Systems Foundations Committee co- chairs, Peter Kandaris, P.E., DiGoia Gray and Associates, and Steve Davidow, P.E., S.E., P.Eng., Quanta Subsurface. The panelists represented the utility, design consulting, construction and contracting, and research communities. Kandaris began the session by stating the committee’s task, as described above, which would be the basis of the dis- cussions to take place. The panelists were: deep foundations for the nation’s power grid rd • Prasad Yenumula, Ph.D., P.Eng., Duke Energy, representing the utilities • Nick Salisbury, Quanta Subsurface, representing construction and con- tracting • Simon Murley, P.E., Power Engineers, and Chih-Hung Chen, P.E., Burns and McDonnell, representing consulting • Armin Studein, Ph.D., P.E., Oregon State University, representing research Process and Methodologies: The Problem Stated A recurring theme was the lack of con- sistency in codes and foundation designs. Kandaris reported that the committee undertook an industry survey in 2014-15 to assess the variances that exist in the industry. The committee is currently developing a white paper based on the results of the survey and a literature review, which he stated, “is focused on the following topics: the design model and methodologies for foundation design; design practices; structure loads and reactions that include materials that are not in the current codes; subsurface conditions and geotechnical parameters; and finally, limit state and performance expectations.” According to Kandaris, one of the key findings, to date, is that “there is no consistent design approach. Practices vary 84 • DEEP FOUNDATIONS • JULY/AUG 2019 Foundation construction in steep, mountainous terrain (photo courtesy of Quanta Subsurface) Murley, a consulting engineer, offered Peter Kandaris, co-moderator of panel discussion from utility to utility and from owner to owner. There is no defined level of relia- bility of risk. Probability-based deter- mination of geotechnical parameters varies significantly. Ultimate and service states are poorly defined. Compatible load factors, resistance factors and performance criteria are not clear. Finally, nonstructural loads that are induced on foundations are not well understood.” his perception of how this effects the design consultant. “Standard design details and materials specifications can vary quite a bit. For example, we rely on ACI 318 as a design specification, even though it states that it is not intended to be used for drilled piers.” The lack of consistency makes it difficult to be properly prepared to deal with condi- tions that vary widely. He pointed out that there are important risks associated with the lack of common standards and, thus, having confidence that a foundation will perform as intended. Another risk is financial. He believes that unnecessary costs can occur when the most cost-efficient designs may not be employed. Chen, also a designer, noted that the lack of common standards and consistent design can have catastrophic operational results. If part of the system fails due to a flawed design, the utility facility cannot operate. “The key point of standards is to maintain the utility facility. Can it be operable?” He used the example of the state
