Dr. N. Ravichandran delivered a talk on “Sustainable Practices in Geotechnical Engineering” at the Faculty

“Nature is NOT an infinite supplier of resources with an indefinite capacity to absorb all waste” 

Dr. N. Ravichandran, Associate Professor in Civil Engineering at Clemson University in the USA, delivered a talk on “Sustainable Practices in Geotechnical Engineering” at the Faculty on 23rd December 2015. This talk was participated by students, researchers, academic staff, Engineers and Directors of organizations and Industries. It was organized by the Institution of Engineers Sri Lanka Northern Provincial Chapter together with the Faculty of Engineering. This dissemination of knowledge events on updating the engineers working in Northern Province is one of the required services. This has been provided by the Faculty from its initiation together with the professional chapters. IESL (NPC) and Faculty of Engineering sincerely thank Professor Ravichandran for sharing state of art in his specialized area through this event.

Abstract of the talk: Delivering a sustainable built environment begins with incorporation of sustainability concepts at the planning and design stages of any project. Geotechnical engineering is one of the most resource intensive disciplines and can significantly influence the sustainability of infrastructure development. There are many ways sustainability can be incorporated in geotechnical engineering projects. They include: (1) use of alternate, environment friendly materials in geotechnical constructions, and reuse of waste materials, (2) robust design and construction that involves minimal resources, financial burden and inconvenience to the society, (3) sustainable foundation engineering that includes retrofitting and reuse of foundations, and foundations for energy extraction, (4) mining of shallow and deep geothermal energy, (5) efficient use of geosynthetics, and (6) reuse of existing geotechnical facilities as possible to minimize waste. This talk will briefly discuss application of waste material (shredded tire) in geotechnical engineering projects, foundation design for tall wind turbines for harvesting clean energy, robust design of geotechnical systems based on reliability concepts and better prediction of surface acceleration during earthquakes. A short summary of recycling waste tires, primary topic of this talk, in geotechnical engineering project is given below.

The applicability of shredded tire as an economical alternative for conventional granular soil backfill for retaining walls was investigated by conducting geotechnical and structural designs as well as finite element simulations. A literature survey was conducted to compile and document the engineering properties of shredded tire. Then, a gravity-cantilever retaining wall was designed for static and dynamic loading conditions considering seismic design parameters corresponding to the Charleston, SC, USA area. Geotechnical design revealed a longer toe compared to heel for shredded tire backfill to maintain stability; however, a shorter footing was needed to maintain overall stability compared to that of granular backfill. Conventional designs and finite element simulations showed significant reductions in computed horizontal deflection at the tip of the wall, structural demand in terms of maximum shear force and bending moment, and construction cost in terms of excavation and material when shredded tire was used as the backfill.

Biography of the resource person: Dr. Ravichandran is an Associate Professor in Civil Engineering at Clemson University in the USA. He received his B.Sc. from the University of Peradeniya, Sri Lanka, M.Eng. from the University of Tokyo, Japan and Ph.D. from the University of Oklahoma, USA. His research interest includes computational soil dynamics, centrifuge testing of geotechnical and structural systems subjected to earthquake loads, finite element modeling of geotechnical and structural systems, reliability based robust design of geotechnical systems. He is the author of two computer programs: 3D-Liq using discrete element method (DEM) for understanding the mechanics of liquefaction at microscale and TeraDysac using finite element method (FEM) for simulating dynamic behavior of unsaturated and saturated soils with structural inclusions. He has published more than 50 journal and conference articles on various topics.