Balancing Classical Solutions With Computer Technology In The Undergraduate Geotechnical Curriculum

One of the desired outcomes of civil engineering technology education is to prepare students for the practice of civil engineering after they graduate. This requires developing student knowledge and competence in the use of standard design practices, tools, techniques, and computer hardware and software appropriate to their technical discipline. 1 To accomplish this, technical courses must balance the coverage of engineering theory with engineering applications typically encountered in practice. Computer technology commonly used in civil engineering practice must be included to achieve this. To meet the needs of employers, students need familiarity with current computer software, as well as an understanding of theories and analysis methods used by the software. Educators must carefully balance the coverage of theory and classical solutions with computer applications to provide students the background they need for their profession. Introduction Many educators rely on their own experiences as students and the material presented in textbooks to select topics covered in their courses. However, computer technology has resulted in many changes to civil engineering practice since many educators were students themselves. Many current textbooks still present classical solutions for many engineering problems. While some classical methods are historically important, their practical use in current engineering practice is limited and their value in the undergraduate curriculum is less important today than in the past. Some methods, however, are still appropriately taught in the undergraduate curriculum. Methods that reinforce basic concepts, solution procedures and behavior still provide students valuable learning experiences. To prepare graduates for industry, educators must balance teaching classical methods that emphasize the solution process and behavior with computer methods graduates will use in industry. Due to changes in the professional practice of civil engineering, updates to what is taught within the civil engineering curriculum are needed. 2,3 This is in part due to the abilities of computers to conduct computations much more efficiently than in the past. 3 Graduates from structural engineering programs with considerable computer usage 4 have an employment advantage over their peers since they tend to be more productive in industrial positions immediately after graduation. In most civil engineering programs, computer software use is introduced into the curriculum directly through discipline specific courses. The literature presents numerous examples of computer usage and software implementation in discipline specific courses. 5,6,7 This can be difficult when hardware or software problems arise or when student questions on software usage result in loss of valuable class and instructor time thereby limiting coverage of technical content. 8 Civil engineering programs using an integrated course format 9,10 show how separate P ge 950.1 Proceedings of the 2004 American Society for Engineering Education Annual Conference & Exposition Copyright ©2004, American Society for Engineering Education computer programming courses can be coordinated with technical courses to develop computer student competencies. Another approach is to use separate software specific “short courses”, in conjunction with required technical courses. 9 In this specific case, 9 students signed up for a oneor two-credit special topics course on using a specific software package while enrolled in a technical course in which the software was used. Although students received credit for the software course, it was not counted toward meeting their degree requirements. It was a formal course, however, so it appeared on their transcripts and was seen as an advantage when looking for employment. Students liked the self-paced format, bi-weekly meetings with the instructor and assignments and exercises using the software. 9 Although other options are available, 8,9,10 most civil engineering educators will need to incorporate computer usage into their discipline specific courses. To successfully accomplish this, faculty must consider which classical solutions most benefit student learning and how they should be utilized. This paper considers some classical methods geotechnical educators should consider as benefiting student learning when combined with computer methods commonly used in industry. Geotechnical cross-sections sketched by hand, elastic stress distribution using charts and equations, elastic settlement calculations, seepage analysis using flow nets, and slope stability charts and hand solutions all emphasize the engineering solution process and encourage student understanding of soil behavior. Yet the approach to such problems in practice commonly involves computer software usage at some level. Practicing engineers must understand the assumptions and limitations of the computer software and must properly interpret the results of these programs. In many cases the classical approach is still worth presenting, but the solution process and behavior should be emphasized rather than calculation details. Computer usage allows assignments involving parametric studies where students can further explore the behavior and limitations of the various analyses. Even with learning computer technology commonly used in practice, today’s engineering students still need to understand the solution process, as well as engineering behavior. Classical analysis methods combined with computer technology provide a way to develop this knowledge. Geotechnical Analysis and Design in Practice Good old fashioned hand calculations and chart solutions are still used on many projects as a quick way to get a feel for engineering performance and behavior, or to check the results of more detailed computer solutions. On small projects with low budgets, hand calculations and chart solutions may actually be the standard of practice. In most cases, however, geotechnical engineers typically use a combination of computer software and spreadsheets, along with more classical approaches to accomplish their work. The engineering challenges, however, are in understanding the important design considerations on a project, relative to the geotechnical site conditions, and the determination, selection or estimation of appropriate properties for use in the analyses. Without a good understanding of the behavior of the ground, and selection of values appropriate for the soil conditions present, the results of even the most sophisticated computer analysis will be suspect. Where computers provide precision in their calculations, geotechnical engineering is a field often based on approximations and estimations. Students of this subject must learn to appreciate the uncertainty involved in the calculations and the assumptions and limitations of the various analysis and design procedures. Where uncertainty in technical values is present, computer analyses provide an easy way to consider the effect of this uncertainty and bracket the range of results expected. P ge 950.2 Proceedings of the 2004 American Society for Engineering Education Annual Conference & Exposition Copyright ©2004, American Society for Engineering Education Classical Approach and Solutions vs. Computer Applications Consideration will now be given to several topics within the geotechnical field where civil engineering educators can supplement classical approaches or solutions with the use of computer technology and software commonly used in industry. In each case, the role of the classical approach or solution is to develop and improve student understanding of concepts and behavior. Computer technology and software is used to supplement the classical approach and is not meant to be a substitute for the classical solution methods. Geotechnical Cross Sections. A decline in the quantity and quality of geotechnical crosssections has been noted 11 and is attributed to the lack of experience recent graduates have in graphical communication and an increased reliance on computers for drafting, analysis and design. Hand-drawn geotechnical cross-sections may seem “old-fashioned,” but their value in site characterization remains. 11 Hammel 11 states that sketching to scale the geotechnical site conditions with pencil and eraser allows time for critical thinking about the geotechnical conditions relative to proposed site development. To develop skills in cross-section development and understanding of site geology, a laboratory class period in introductory geotechnical engineering courses can be devoted to researching site geology, site exploration methods, and cross-section development. Students often want to develop their cross-sections on the computer, especially those with considerable CAD experience. When this is allowed, students often interpret the assignment as an exercise to practice their CAD skills and focus too much on developing a perfect drawing, rather than an exercise to learn to appreciate the variability, uncertainty, and significance of the geologic conditions at the site. Requiring cross-sections to be sketched by hand requires students to think about the variability of the geologic deposits at a site, as well as the characteristics of the soils present, relative to the proposed development. The sketching assignment should require students to reflect on the geotechnical conditions at the site and write detailed engineering report quality paragraphs describing the conditions. If desired, a computer generated cross-section can be prepared once a hand-sketched cross-section is developed. Elastic Stress Distribution. Text books all present elastic stress distribution theories and a variety of tools using those theories to estimate changes in stress beneath different load configurations. Equations and charts are available to predict these changes in stress. While historically these equations and charts were the standards used in engineerin