Friday, April 25, 2014 06:41 AM

Seismic safety

FEB 16 -

The Sikkim-Nepal earthquake is an awakening call.  All developers, engineers, policy makers, planners, home owners, home buyers (stakeholders) in Kathmandu and other parts of Nepal must be committed to mitigating earthquakes hazards.  Historically, Nepal suffered at large from earthquakes.  The events of 1834 and 1934 testify to the disastrous nature of an earthquake’s aftereffects. These are catalogued in history books and old photographs. The potential for future earthquakes and their devastating effects cannot, and should not, be under-estimated or ignored.

Crowded centres in the Valley will sustain catastrophic loss of life in a major earthquake event. The current uncontrolled and unmanaged growth and development, coupled with the inherent lack of proper infrastructures cannot escape from a major seismic event impacting the Valley. The results will be devastating damage and loss of countless lives. 

Common sense observation proves that access to structures in and around the Valley is very difficult even under normal circumstances.  Imagine the following:  fires and smoke, caused by exploding gasoline stations or exploding storage areas for gas cylinders in the middle of urban dwellings, blanketing the skyline, occupants above floors that store natural gas screaming for rescue,  cries of help from a 100 million people, rescue personnel and equipment desperately trying to reach damage destinations through these narrow roads and alleys, blocked by fallen building structures, fires and other obstructions, flashing sirens of fire trucks and rescue vehicles stuck in the chaos, a city without proper water supply or proper fire trucks to fight these fires.  For Kathmandu Valley, these images are a potential reality after a massive destructive earthquake.

Kathmandu Valley is endowed with some of the world’s most unique cultural heritage sites and structures. This creates another major unique issue for seismic preparedness and earthquake resistance.  Their preservation, a daunting task in itself, is of paramount importance. Should these unique, valued heritage and cultural sites be retrofitted to resist seismic forces?

Unless stakeholders in the land development process invest, develop and implement a comprehensive and sustainable plan for Land Development in Kathmandu Valley, recognising the serious impact of a catastrophic seismic event, this nation will face an unfathomable crisis.

If life is valued and protected, a critical first step must be enforced immediately. The efforts by organisations such as Nucleus for Empowerment through Skill Transfer

 (NEST) need recognition.  Various articles and concerns voiced in local publications are an encouraging sign too.

Unfortunately, slogans, prayers, articles, and publications don’t deter earthquakes. Sustained serious commitment and a conscientious cooperative effort amongst government officials, architects, engineers, planners, land developers and individual building owners and builders is necessary to ensure seismic safety.

Seismic safety includes issues related to (1) making existing buildings, including heritage sites/structures, and current and future building structures, earthquake resistant, (2) developing and providing adequate infrastructure for first responder teams and their equipment to reach disaster locations (3) having needed equipment, (4) having adequate water supply and pressure  to fight fires, etc. Much more serious work needs doing. Commitments need to be made.

The current building growth, including the mushrooming tall structures, raises several important multi-dimensional concerns.  Avoiding technicality and without focusing on the vitally important concern of the seismic resistance capabilities of currently built structures, response to some basis questions is required:

•    After a seismic event, what is the acceptable level of risk of death and destruction?  Will society accept 100,000 or a million deaths? Or will society demand minimum loss of life and extensive damage to structures?

•    After a seismic event, are infrastructures adequate to permit rescue operations? Is the current infrastructure acceptable?

•     Should governing and municipal authorities permit construction of new buildings without first ensuring the completion of adequate infrastructure?  These infrastructures, at a minimum, should ensure adequate access to structures, provide sufficient water supply for fire-fighting with appropriate fire-fighting equipment, including fire trucks and trained manpower that can meet the challenges of tall structures. 

•    Is the existing fire-fighting system capable of meeting the fire risks raised by tall structures? Most modern fire trucks have a maximum reach height of 75 feet. To be effective, the road infrastructures including bridges have to be designed to sustain dynamic and static loads resulting from their use.

•    Are enforceable control mechanisms in place to check and certify the adequacy of the design and construction of structures that will be impacted by anticipated seismic forces?   

Under current national environment and circumstances, a positive answer would be a miracle.

Are there viable, proven solutions? Recommendations based on observed practices and program in San Diego and California are presented.

•    Achieve consensus amongst the land development stakeholders. Each must be committed to their role in the land development process and to the construction of adequate infrastructure prior to new development.  This may be more easily said than done.  Perhaps, revenues obtained through the permitting process should be transparently used exclusively for land development projects.

•    Achieve consensus amongst the land development stakeholders to ensure that development along historical and cultural heritage sites are vested sites.  Their protection, preservation and retrofit against earthquakes should be a local, national concern and commitment.

•    For the moment, respect and honourably enforce existing land development laws and building codes.  Future improvements on these rules and regulations shall be an ongoing process.

•    Mandate that all design and construction meet the written review and comments of independent qualified professionals that currently practice design, construction and inspection of structures. The result: a strong impartial authority with the vested rights and duty to enforce honourably the best practices for seismic design, inspection and certification of structures.

•    Don’t deviate from approved plans, permits for all construction.

•    Consumers! Ask stakeholders how structures have been designed to resist earthquakes.

Baidya, a civil engineer, practices structural engineering and code compliance and is retired from the Development Services Department of the City of San Diego, California

Posted on: 2012-02-16 08:58


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