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Solving ill-structured problems is a complex task that is required of engineers who work in industry. To better prepare undergraduate engineering students for this complex task and their future professional careers, this paper provides an analysis of the results of research focusing on the study of problem-solving processes adopted by civil engineering students, faculty members, and practicing engineers. This exploratory work presents findings concerning the way in which 16 participants solved an ill-structured engineering problem and examines similarities and differences between the participants in terms of their problem-solving processes. This study was guided by the following research question: What specifically are the problem-solving processes of (1) students, (2) faculty, and (3) practicing engineers, and what are the similarities and differences between them when solving an ill-structured problem? In order to answer this research question, verbal protocol analysis was used. Participants were asked to think aloud as they formulated potential solutions to the proposed problem. Our findings indicate some distinct differences between students, professors, and practicing engineers in their problem-solving processes. Faculty were found to double-check their solutions and make assumptions more than students and practicing engineers, while students were found to express their feelings more and use analogies and outside knowledge less than faculty and practicing engineers. These differences between students, faculty, and practicing engineers suggest that engineering curriculum and instruction should supplement well-structured problems with ill-structured problems in engineering classrooms in order to help students become familiar with multiple problem-solving approaches available to them and better understand the connection between the workplace and the classroom.

This paper examines the bio-derived stabilization of sand-only or sand-plus-silt soils using an extracted bacterial enzyme application to achieve induced calcite precipitation (ICP). As compared to conventional microbial induced calcite precipitation (MICP) methods, which use intact bacterial cells, this strategy that uses free urease catalysts to secure bacterial enzyme-induced calcite precipitation (BEICP) appears to offer an improved means of bio-stabilizing silty-sand soils as compared to that of MICP processing. Several benefits may possibly be achieved with this BEICP approach, including bio-safety, environmental, and geotechnical improvements. Notably, the BEICP bio-stabilization results presented in this paper demonstrate (i) higher rates of catalytic urease activity, (ii) a wider range of application with sand-plus-silt soil applications bearing low-plasticity properties, and (iii) the ability to retain higher levels of soil permeability after BEICP processing. Comparative BEICP versus MICP results for sand-only systems are presented, along with BEICP-based results for stabilized soil mixtures at 90:10 and 80:20 percentile sand:silt ratios. This BEICP method's ability to obtain unconfined compressive strength results in excess of 1000 kPa with sand-plus-silt soil mixtures is particularly noteworthy. Key words: shear strength, bio-stabilization, enzyme, bacteria. Cet article examine la stabilisation bioderivee des sols de sable uniquement ou de sable-plus-limon en utilisant une application enzymatique bacterienne extraite pour obtenir une precipitation induite par la calcite (PIC). Comparee aux methodes classiques de precipitation de la calcite induite par des microbes (MICP), qui utilisent des cellules bacteriennes intactes, cette strategie qui utilise des catalyseurs a l'urease libre pour obtenir une precipitation calcique bacterienne induite par des enzymes (BEICP) semble offrir un moyen ameliore de biostabiliser les sols de sable limoneux par rapport a celle du traitement MICP. Plusieurs avantages pourraient etre obtenus grace a cette approche BEICP, notamment les ameliorations en matiere de biosecurite, d'environnement et de geotechnique. Notamment, les resultats de bio stabilisation de l'IPCEB presentes dans le present document le demontrent: (i) des taux plus eleves d'activite d'urease catalytique, (ii) une plus large gamme d'applications avec des applications de sol sablo-limoneux ayant de faibles proprietes de plasticite et (iii) la capacite de conserver des niveaux plus eleves de permeabilite du sol apres le traitement par BEICP. Les resultats comparatifs du BEICP et du MICP pour les systemes utilisant uniquement du sable sont presentes, ainsi que les resultats bases sur BEICP pour les melanges de sols stabilises a des rapports sable-limon de 90 : 10 et 80 : 20 pour cent. La capacite de cette methode BEICP a obtenir des resultats de resistance a la compression non confinee superieurs a 1000 kPa avec des melanges de sol sable-plus-limon est particulierement remarquable. [Traduit par la Redaction] Mots-cles: resistance au cisaillement, biostabilisation, enzyme, bacteries., Introduction This paper's presentation of a bacterial enzyme-induced calcite precipitation (BEICP) procedure represents yet another iterative refinement of the overall concept of bio-inspired soil stabilization, which has evolved over the [...]