Using Computer Modeling To Increase Student Comprehension Of Foundation Behavior And Capacity

Computer modeling in engineering and technology is not only a powerful analytical tool for design, it also has significant potential as an educational tool to help students better visualize and understand the behavior of different elements in engineering systems. Some prior studies have been performed by others where computer simulations were used in an attempt to increase student comprehension of certain concepts in engineering courses. Improvements in learning were observed in some of these investigations, but overall the reported impact and effectiveness of this approach appears to be mixed. Few prior studies have investigated the effect of computer modeling on student comprehension of the behavior and static load capacity of spread footing and pile foundations, which are commonly used in civil engineering to support structures on soil. The purpose of the study presented in this paper is to evaluate the impact of computer simulations on reinforcing and improving undergraduate students’ computational abilities and understanding for spread footing and pile design. The investigation is motivated by the observation that although undergraduate students in civil engineering learn the theories and computational approaches for evaluating the load capacity of these foundation types, they often do not fully appreciate how the foundation interacts with the soil and how load-carrying capacity is developed from that interaction. As a result, they often struggle with calculating the loads that can be supported by spread footings and piles, particularly for non-uniform soil conditions existing in layered soil profiles. In the current study, undergraduate Civil Engineering Technology students in a foundation design course at Rochester Institute of Technology performed analyses of spread footing and pile load capacity using the computer modeling software FLAC, in addition to performing traditional manual calculations based on theory, as part of their homework. FLAC uses a finite difference approach to solve modeling problems. The effectiveness of the FLAC simulations for enhancing and strengthening the students’ computational skills and understanding for the load capacity and behavior of these foundations was evaluated by comparing the examination performance of students who used the software with the performance of those from the prior academic year who did not use it. Statistical analysis of the data indicate some improvement in the ability of undergraduate students to manually compute the load-carrying capacity of spread footings and piles in a layered soil profile when they used FLAC modeling in addition to traditional manual computations. The group who used FLAC also gained an appreciation of the importance of the depth factor in the load capacity calculations for footings. In general, students indicated the software helped reinforce their understanding of spread footing and pile foundations. Student feedback also confirmed the importance of providing adequate background on how the software operates. The results of this study show that computer simulations using advanced modeling techniques can be successfully implemented in undergraduate engineering or engineering technology courses to reinforce and improve student comprehension and their manual computational abilities for design of engineering system components, such as foundations supporting structures. P ge 14316.2 Background and Hypothesis In civil engineering, students can struggle with clearly understanding the physical behavior of elements in a civil engineering system and relating it to the theory and equations used to design the system. The author has found this to be true in the design of spread footing and pile foundations, particularly in layered soil deposits with more than one soil type. As a result, when students are faced with designing a spread footing or pile in a layered soil deposit, they often have difficulty with correctly applying the appropriate theory and associated design equations. Previous studies performed by others over the last ten years have shown the potential of using computer simulations to increase student comprehension of engineering systems and designs, particularly in the areas of mechanical and civil engineering. Most of these studies investigated the use of finite element analyses in engineering classes to improve student learning. Cole 1 and Waldorf 2 both indicated that using finite elements in classes to improve student learning can be helpful, but teaching students the basics of how to perform these analyses in a limited amount of time is difficult. Baker et al. 3 used an approach where students were given macros to run finite element analyses, rather than trying to teach them how to set up an analysis. Students in this study indicated that performing the analyses helped them to visualize the problems they solved, but there was no quantitative data collected on changes in student performance. Three different studies were done at the U.S. Air Force Academy by Borchert et al. 4 , Bowe et al. 5 , and Rhymer et al. 6 where multicolor stress contour diagrams, obtained from finite element analyses of materials under loading, were used in some lecture sections to improve learning. In the first two studies (Borchert et al. 4 and Bowe et al. 5 ) no consistent improvement in learning was observed between students who were taught with the finite element results versus those who were not. However, in the last study, where less time was spent explaining the basics of finite element analyses and it was emphasized that there would be finite element related questions on quizzes and exams, there was a noticeable improvement in the quiz and exam performance of students who were taught using the finite element results in comparison to those who were not. Steif and Gallagher 7 , who had their undergraduate engineering students use finite element analyses to solve seven mechanics of materials type problems, reported that the students found the finite element analyses slightly to somewhat valuable and doing the analyses improved their understanding little to somewhat. More recent studies performed by Brown et al. 8 and Brooks et al. 9 showed statistically significant increases in student learning as a result of using finite element analyses. Brown et al. 8 reported mean quiz scores for two groups of students before and after they used a finite element module dealing with stresses in a curved beam. In 2006 the mean quiz scores before and after use of the module were 71.1 and 82.2 percent, respectively; in 2007 the mean quiz scores before and after use of the module were 52.8 and 65.3 percent. Both of the increases in mean quiz scores were statistically significant. Brooks et al. 9 looked at the effect of using a finite element program for pavement analysis on student knowledge about the impacts of geometric conditions, material conditions, and environmental conditions on pavement design. Student knowledge (evaluated on a scale of 0 to 100 percent) about geometric condition impacts on pavement design was 64 percent before and 77 percent after use of the finite element analysis, knowledge about material condition impacts was 61 percent before and 72 percent after, and knowledge about environmental condition impacts was 60 percent before and 67 percent after. All of these P ge 14316.3 changes in student knowledge were reported as being statistically significant and were based on student ratings of their own knowledge. In the area of foundation design in civil engineering, very few studies have been done using advanced computer modeling to improve student understanding. Lobo-Guerrero and Vallejo 10 discuss examples of how advanced computer modeling based on the discrete element method can be used to illustrate certain behaviors in geotechnical engineering, including spread footings and pile foundations under applied loads. However, they do not report any data showing the effectiveness of this approach for improving student learning. The study presented in this paper looks at the following hypothesis: Advanced computer modeling software can be an effective tool for civil engineering students to check their hand calculations of footing and pile load capacities and its use can reinforce and improve their understanding and manual computational abilities for design of these foundations. It is based on the observations listed below. ≠ Spread footing and pile foundation design is an important topic in civil engineering. ≠ Civil engineering students sometimes struggle with understanding spread footing and pile behavior leading to difficulties in calculating the load capacity of these foundations, particularly in layered soil deposits. ≠ Advanced computer modeling software has been shown to improve student comprehension and performance in other engineering areas, but there is no specific data demonstrating such an improvement for spread footing and pile foundation design. Details of the study conducted, as well as the results and conclusions, are presented below.