Development of the Geoconstruction Information and Technology Selection Guidance System (2014)

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35 C h a p t e r 6 Understanding the limitations of the Information and Guid- ance website are critical to its proper implementation and use in practice. Some of the limitations of the information and guidance system include the number of technologies consid- ered in the system, the difficulty in measuring the results of the selection system against the opinion of an experienced geotechnical engineer, and the difficulty of anticipating pos- sible project-specific scenarios, as discussed in more detail in this chapter. This information and guidance system provides tools for engineering of geotechnical solutions. It does not “engineer” solutions, because that must be performed on a project-by-project specific basis. Information and Guidance System Limitations At present, the United States lacks a comprehensive, integrated system that provides critical data relating to geoconstruction technologies. The information and guidance system described in this report represents the first significant attempt at develop- ing a useful tool to promote the widespread use of geoconstruc- tion technologies in transportation infrastructure projects. The user must recognize this system is the initial attempt and fully understand and accept the limitations of the system. Inappropriate application of System by Inexperienced personnel The Geotechnical Solutions for Transportation Infrastruc- ture system is not a “black box” that provides solutions that can be blindly implemented. During the development stage, every review group expressed concern that the potential exists for inexperienced users to inappropriately apply the informa- tion provided on the website. The structure and availability of documents were developed with the intent to minimize this potential. For example, many reviewers suggested that the cost-estimating spreadsheets be made available directly on the Technology Information web pages. However, the spreadsheets can only be accessed through the cost informa- tion product, which forces the user to access the critical infor- mation required to complete a meaningful cost estimate. The use and application of this system is the responsibility of the user. It is imperative that the responsible user under- stands the potential accuracy limitations of the program results, independently cross checks those results with other methods, and examines the reasonableness of the results with engineering knowledge and experience. Limitation recapitulation: The information and guidance system is not a “black box.” Limited Number of technologies in System Although a large number of technologies are included, the technologies were limited to the defined scope of the SHRP 2 R02. The information and guidance system summarizes 46 geoconstruction technologies. The system contains two tradi- tional solutions, which are excavation and replacement, and traditional compaction. Other traditional solutions were beyond the scope of the project, such as piles, shafts, sheetpiles, and cast-in-place retaining walls. Additionally, some emerging technologies that could also provide viable solutions for proj- ects in the United States were excluded from the system. Limitation recapitulation: The information and guidance system contains a limited number of geoconstruction technologies. technology-Specific Information The information provided in the information and guidance system is current as of the time of report and system/website release. During the 3 years that the information and guidance system was being developed, technology-specific information Limitations of the Information and Guidance Website

36 was continually being updated. As emerging technologies become more established, updating of technology-specific information is necessary. One of the primary reasons to pro- vide a web-based system is that is it updatable. Limitation recapitulation: The information and guidance system information is current as of the date of development (or future update). Selection System Limitations The selection system outlined in this report presents the first attempt at an automated, publicly available system to assist in the selection of a geoconstruction technology for transporta- tion applications. The selection system has a unique set of limitations. Selection System Does Not replace engineering Judgment The selection of an appropriate technology is the responsibil- ity of the user. The users that access the system will have greatly varying degrees of education, experience, and posi- tion. Regardless of a user’s background, all users must recog- nize the value of a local, experienced engineer’s judgment. The website is not intended to be a “black box” for users. Rather, the website is intended to assist the user in reaching a decision regarding the use of a geoconstruction technology. Marr (2006) developed five “take-home messages” concern- ing geotechnical engineering and judgment in the informa- tion age that should be considered by the users using the information and guidance system. • Engineering judgment without relevant experience is weak. • Engineering judgment without relevant data is foolish. • Good judgment needs good data and evaluated experience. • Good judgment is essential for the effective use of infor- mation technology tools. • Good judgment is central to geotechnical engineering, even in the information age. Limitation recapitulation: The information and guidance sys- tem does not replace engineering judgment. Selection System Leads to Single technologies The selection system leads the user to a list of unranked, tech- nically feasible geoconstruction technologies. In practice, a combination of geoconstruction technologies may be used. To assist the user in evaluating possible combinations of technologies, a White Paper on Integrated Technologies for Embankments on Unstable Ground was prepared and made available on the website. Limitation recapitulation: The selection system leads the user to individual geoconstruction technologies, where combina- tions of technologies may be used on some projects. Selection System Uncertainty Although several cycles of review and revision have evaluated the selection system, a certain project may use a geoconstruc- tion technology that the system has eliminated. Consider- ing the wide-ranging geologic conditions across the United States, combined with the wide-ranging project types, there exist solutions to projects outside of the solutions proposed by the selection system. The intent of the system is for the user to use engineering judgment to evaluate the set of can- didate technologies. Additionally, the field of geo construction technologies is continually evolving with the application of new and existing technologies to a wider range of project conditions. Limitation recapitulation: Other technically viable solutions may likely exist for a project beyond the list of geoconstruc- tion technologies output by the selection system.