Kike Garzon-Sabogal, a PhD candidate in the Lyles School of Civil and Construction Engineering.

Grain is typically associated with agriculture, an offshoot of its long-standing roots in antiquity as a unit of measurement based on seeds like wheat and barley. In general terms, grain is a measurement of a unit of mass, and things can be thought of as an agglomeration of those individual grains, or granules. Kike Garzon-Sabogal is a PhD candidate in the Lyles School of Civil and Construction Engineering, which trains the next generation of engineers in the best processes and materials for sustainable structures. His research aims to gain an understanding of material behavior at a grain scale in order to “tune” material properties for different performance outcomes and behaviors in dynamic events like vibrations and earthworks.

What investigative avenues are you pursuing?

As part of the Geotechnical Engineering research group, I have focused on investigating granular materials. Specifically, I have been studying their dynamic properties: their deformability and their ability to dissipate energy.

Granular materials are important to many fields, particularly in civil engineering, where they make up a large portion of the materials used in the construction of infrastructure. Their deformability is quite complex, and characterizing this feature can improve infrastructure serviceability.

Their ability to dissipate energy is relevant to address dynamic events of many types, from sounds and vibrations of human origin to those of natural origin like earthquakes. These dynamic properties are affected by many factors, like fluids and past and current loading conditions, but also by the characteristics of the individual grains, like shape and composition.

I am trying to exploit the impact of individual grain characteristics to tune dynamic properties. In fact, I have developed a new granular material where the individual particles are made of two distinct solid phases. Most of my work takes place in the laboratory, where I subject specimens comprised of many particles to many types of vibrations. I am also exploring the behavior of these materials at a smaller scale, by testing the contacts between pairs of particles.

What spurred your interest in this line of research?

There were three aspects that drove me to this investigation:

1) During my undergraduate education, the study of ground materials was always portrayed as challenging due to the diversity of phenomena and non-intuitive material responses; for instance, materials like sand are able to behave both like solids or fluids. To understand these complex responses, a researcher would require knowledge of different fields, like solid and fluid mechanics, chemistry, programming and mathematics. The multidisciplinary nature and the challenge itself were what initially drove me to this line of research.

2) As I moved forward in my academic career, I perceived that load-bearing applications for infrastructure took the spotlight in geotechnical engineering. While these are of great importance to the safety, survival and progress of our civilizations, to me they did not seem visible enough (to the naked eye). For example, when load-bearing structures perform successfully, it can be imperceptible. Since visibility was important to me, I decided to focus my research on shorter-term events with more visible impacts, such as vibrations, commonly referred to as dynamic events.

3) Finally, I wanted to include in my professional endeavors my intense interest in graphic and architectural design. As I became aware of the impact of the characteristics of individual grains on the behavior of their ensembles, I started to consider grains as a perfect canvas to bring design into my geotechnical engineering experience.

Why did you choose Purdue to continue your studies as a graduate student?

I had the opportunity to experience Purdue as an Undergraduate Visiting Scholar, allowing me to see many attractive aspects that drove my school choice. I was part of a supportive research group, where quality and collaboration were very important. The group consisted of several faculty members, including emeritus professors that paved the way in the field and were open to mentoring me and addressing my questions. I was also trained in performing cutting-edge experimental methodologies and given autonomy to use them in the laboratory.

Another resource that attracted me was the Colombian Student Association at Purdue (CSAP), which is one of the largest Colombian graduate communities in the United States. This resource not only helped in facing the difficulties of international mobility, but also provided a space to share research from a plethora of fields that drove scientific collaboration and support. Also, the research partnership that Purdue has with agencies like the Indiana Department of Transportation offered the possibility to conduct research with immediate impact next to active professionals, live construction projects and extensive resources.

When did you first get interested in engineering and science?

The origins are quite humble, mostly rooted in performing well in high school level math and science courses, as well as having a passion for creation. I attended a technical high school where, along with an academic curriculum, students were trained in a trade. Many trades were offered: technical drawing, electronics, machining, woodwork, graphic design, etc. I always seemed to lean towards the trades that would help me create, but also link the production process to fundamentals. The trades that I practiced the most were technical drawing and machining. I thought at the time that pursuing engineering would give me more fundamentals to continue pursuing creative endeavors, either in a digital context or a tangible one.

What’s it like studying at Purdue?

Studying at Purdue has always been stimulating, since there are great research quests to take part in as well as tools to support you while you engage in those endeavors. I have been mentored and taught by professionals that believe in my potential and care about my growth. In most of my research projects I have been guided by at least two faculty members. This enabled an open dialogue where my suggestions are valued, and where tools were offered to help me realize my ideas. In my experience at Purdue, the boundaries between scientific fields do not seem strict and overbearing. Numerous times, I have been helped by students and faculty members from other departments to address the needs of our projects. This has included access to their facilities, along with mentoring and advice.

My advisors have also given me curricular freedom to pursue courses that are not traditional to the graduate program. For instance, I was able to take several classes in computer vision, computer graphics and visual intelligence, which I had been interested in for a while. Becoming trained in these subjects was extremely beneficial to my research, as it introduced me to some fundamentals of imaging that I used to develop my own tools, which were later published.

Throughout my time at Purdue, I have also been supported by many undergraduate students whose efforts have made progress in the research team possible. These students bring motivation and a fresh view on our ideas that lead to more motivation in the work, and on many occasions alternative perspectives to the way we work. Several of those students, for instance, have suggested how to make my research equipment work more effectively.

The graduate student environment is very open; students are constantly talking about their work. A doctoral program is rewarding but also challenging and sharing my shortcomings in the lab with other students has, many times, been the first step to getting solutions.

What else have you learned at Purdue, beyond subject matter?

I very much enjoy designing granular materials; however, this venture appears to be unconventional when compared to other practices in the field. A person runs into many risks while exploring unconventional territories: dead ends, inefficient use of resources and difficulties in introducing the unconventional into the mainstream. While these risks were taken, it was not done blindly. My advisors at Purdue taught me how to better distribute my efforts to make this investigation happen, from extensively discussing the goals of the research and properly testing its feasibility, to conducting carefully designed experimental programs. These tasks were performed both to achieve technical goals and to gather data to support future efforts in this direction. I have learned that commitment to any endeavor is apparent when risks are taken responsibly. This often requires coming back to the drawing board to reaffirm or rediscuss the objectives of the investigation.

What is the Purdue research environment like? Have you had chances to teach, and publish?

As perhaps I have hinted in my previous answers, Purdue’s research environment is very nurturing and thrives in being collaborative. I would add that I have been fortunate enough to have worked with undergraduate students, and I am glad Purdue promotes their participation in research early on in their education. The experience has been very rewarding. It has helped me improve my communication skills, and design laboratory work to fulfill both research objectives as well as educational goals. For example, a laboratory experiment can be selected and designed with the goal of driving the investigation forward, but also to teach students about fundamentals and motivate them to pursue work in the field. Involving undergraduate students in research also allows a new generation to be exposed to the open-ended questions and problems of the field.

I have also been fortunate enough to have published papers in dynamic testing of geomaterials and field assessment of pavement structures. I presented my research in various conferences, specifically one focused on imaging of coarse granular materials (GeoCongress 2024, Vancouver, Canada), and more recently preliminary results of the dynamic properties of my novel multiphase particles. In the latter conference (International Symposium on Geomechanics from Micro to Macro, Grenoble, France) our poster tied for first place in the competition.

I have also been awarded several travel grants by the Purdue Graduate Student Government (PGSG), the Colombian Student Association, the Lyles School of Civil and Construction Engineering, and the Purdue Geotechnical Society. Last year I received a travel grant by the United States Universities Council on Geotechnical Education and Research (USUCGER).

What advice might you give to other students deciding where to attend graduate school?

I strongly believe that a good graduate school experience is linked to good professional relationships. A good working environment should be a decisive factor in selecting a school for graduate studies. During their interviews, I encourage applying students to ask about the type of mentorship that they will receive. I also encourage them to reach out to current students to create a picture of the working environment in the schools they are considering.

I recommend reviewing the resources that universities provide for their graduate students beyond the regular curriculum that can be beneficial during their program. For instance, one of Purdue’s most useful organizations is the writing lab. Written communication is a critical skill for graduate students, and this organization advises and supports students at different levels, providing individual counseling and coaching. Graduate school is a rewarding experience but can also be demanding for an individual. Therefore, other resources like personal counseling and mental health support can be key to a successful graduate student career.

What about the future? What are your goals; what are you looking to accomplish?

I want to continue my career as a researcher and am looking to do it at a university because I find them to be very stimulating environments, where unusual collaborations can arise. I see myself in the future as a faculty member in an engineering school exploring the overlap between arts, science, and engineering. I would like to continue to advocate for undergraduate research programs with students from South America, providing them with research tools and strategies so they can experiment with the engineering problems that they face.

Might you share with us a little window into your personality: some distinctive trait, habit of mind, hobby/pursuit outside work…?

I have a passion for all things graphic: graphic design, graphic novels, and arts and film production. I frequently sketch and dabble with illustration. I try to do it as often as possible, and every so often try to bring inspiration from research to my illustrations, and vice versa.