Monday, October 21, 2013

Addressing Safety & Sustainability of Infrastructures in Hazard-Prone Countries

Keynote Paper delivered at Nagoya University's
International Forum on CE Infrastructure Technology Transfer, 31 August 2013
“Civil Engineers shall hold paramount the safety, health and welfare of the public and shall strive to comply with the principles of sustainable development in the performance of their duties.” This is one of the fundamental canons of the Code of Ethics of Civil Engineers. The task of a civil engineer includes provision of safe, reliable and comfortable infrastructures for housing, transport, communication, water supply and sanitation, energy, commercial and industrial activities to meet the needs of a growing population. Today, there is an increasing demand for civil engineers to focus their efforts on the protection and preservation of the environment. With the increase in severity and frequency of natural disasters that devastated both developing and advanced countries,  planning, design and construction of infrastructures that are safe for people and at the same time reduce their impact on further deterioration of the environment becomes a major challenge. Civil engineers who are experts in the various fields of specialization in structural engineering, transportation engineering, water resources engineering, geotechnical engineering and construction engineering must embed in their tasks disaster risk reduction especially in hazard-prone regions – for when they do this, they not only address safety but also sustainability – two important issues for maintaining the balance and harmony between the built and natural environment.
Living in hazard-prone regions. Achieving safety and sustainability is a major challenge in regions or countries that are vulnerable to adverse natural hazards like earthquakes, typhoons, floods, volcanic eruptions, drought and tsunamis. The vulnerabilities of the built environment to a hazard depend on the safety provided and sustainability features. The disaster will have impacts on both the built and natural environment.


Sunday, June 9, 2013

Greener Designs of Buildings using the Structural Sustainability Index

Sustainability is a concern that must also be addressed by structural engineers. Structural engineers must be able to discriminate as to which materials and processes would have a lesser impact to the environment, and to coordinate with the other stakeholders of the structure. The concept of the study is to enable the structural engineer to analyse the sustainability of structural systems in a quantifiable manner. 

In designing a house, or any structure, there are three things commonly considered by the structural engineer. Namely: safety, serviceability and cost. Safety and serviceability ensure that the structure can fulfill its intended purpose by satisfying code requirements on strength, ductility and deflections. Addressing economy, on the other hand, requires value engineering to produce an optimum design with reasonable cost. There is now an increasing concern about the environmental impact of structures. Sustainable design of houses must be pursued to address this concern. But what parameter may be used to guide structural designers to make their structures “greener”?

In an undergraduate thesis, the environmental impact of the structural systems and envelope of selected housing units for a middle class family in the Philippines using Life Cycle Analysis (LCA) was conducted.  The five environmental impact parameters: (a) Global Warming Potential, (b) Ocean Acidification, (c) Abiotic Material Depletion, (d) Energy Use, (e) Human Toxicity were assessed considering the manufacturing and disposal stage as the system boundary in the LCA study. A  “Structural Sustainability Index” or SSI which produces a single score aggregating the five impacts was derived by assigning weights based on an expert’s survey for each environmental impact indicator. The SSI can be used for ranking houses based on environmental impact and can be used as a parameter to guide structural engineers in comparing various design alternatives and selecting  “greener designs”.

The image below is a poster submitted to the ASEP Student Research Competition during the 16th ASEP International Conference held on May 23-25, 2013.