Sunday, January 4, 2009

Designing for Safety & Stability Leads to Sustainability

Today, there is an increasing demand for engineers to focus their efforts on the protection and preservation of the environment. The civil engineering community, which includes structural engineers, plays a major role in maintaining the balance and harmony between the built and existing natural environment. The built environment, which includes infrastructures such as residential houses, high-rise buildings, long-span bridges, roads and expressways, and large civil structures like dams and reservoirs, provide for a livable atmosphere for all. However, the impact of these infrastructures on the natural environment especially in natural hazard-prone countries like the Philippines should be a concern. Richardson (2002) summarizes the realities of infrastructure impact on the environment as follows: It is said that 50% of the world population lives in cities today and this may grow to 75% by 2030. Cities are said to cause 75% of the world’s pollution and consume 75% of the world’s energy. Buildings are reported to produce 40% of the world’s CO2, consume 50% of the energy derived from fossil fuels, consume 3 billion tons of raw materials in construction each year and consume 75% of all energy used through artificial lighting, heating and cooling every day. 25% of all wood harvested is used in building construction.

The negative impact of infrastructures on the environment aggravates especially when natural disasters occur. Natural disasters like earthquakes, floods, typhoons, tsunamis and landslides spoil both the built and natural environment. Aside from causing numerous deaths and injuries to people, natural disasters had caused the destruction of important infrastructures such as buildings, bridges and roads and devastation of nature which contributed to environmental degradation. The 1999 Chi-Chi earthquake in Taiwan caused 2,415 deaths, 1,441 severely wounded, US$9.2 billion worth of damage, 44,338 houses completely destroyed and 41,336 houses severely damaged. The 2001 Gujarat earthquake in India was the most devastating earthquake in India in recent history. The quake destroyed 90 percent of the homes in Bhuj, several schools, and flattened a hospital. Gujarat's commercial capital and a city of 4.5 million, as many as 50 multistory buildings collapsed and several hundred people were killed. In the July 16, 1990 earthquake in the Philippines, damage to buildings, infrastructures, and properties amounted to at least P 10B. The Hyogo-ken Nanbu earthquake in Japan which hit the city of Kobe and surrounding areas in Hyogo prefecture on January 17, 1995 cause the collapse of nearly 55,000 houses in the city of Kobe. The cost of reconstruction of buildings alone was roughly estimated at between US $61-70 billion.

As a consequence of the destruction brought about by natural disasters, the natural resources, materials and energy that have been utilized in constructing these infrastructures have been put to waste. Moreover, the large amount of disaster-caused waste and debris poses another environmental problem. The most severe natural disasters generate debris in quantities that can overwhelm existing solid waste management facilities or force communities to use disposal options that otherwise would not be acceptable.

How may structural and civil engineers contribute towards the reduction of these negative impacts in a region where natural disasters like earthquakes, typhoons, tsunamis and landslides are prevalent? Structural and civil engineers have significantly contributed towards the protection and conservation of the natural environment especially when we consider the impact of natural disasters. on infrastructures and the environment. Civil and structural engineers, when they properly design structures and foundations for safety and stability, are actually contributing significantly to the preservation of the natural environment. Proper analysis, design and construction of structures will minimize damage or collapse. Refined modeling, testing and analysis of soil may prevent foundation failures. Strengthening and improvement of unstable slopes will control the occurrence of landslides. When structures are strengthened or retrofitted, the usable life of the structure is extended reducing end-of-life waste. These primary responsibilities of structural and civil engineers regarding safety and stability, in the end, leads to the reduction of non-renewable natural resources consumption and minimizing the accumulation of construction waste and disaster-caused debris waste. The responsibility of structural and civil engineers in designing for safety and stability and the role they play concerning the maintenance of environment especially in disaster-prone countries must be appreciated by everyone including the so-called “environmentalists.”

This article was published at the Philippine Star, Star Science Column, 6 March 2008

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