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Prepared by:Divine Sebastian

Lamar University

A CASE STUDY ON GUADALAJARA SEWER EXPLOSION(1992)

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INTRODUCTION

• One of the most catastrophic corrosion disaster till date.• Happened on Wednesday 22, April 1992 at 10:09 pm in Analco

district of Guadalajara city, Mexico• Led to a series of explosions for a duration of 4 hours.• Followed by two more explosions on the next day at early

morning.• The explosions were occurred due to the ignition of accumulated

gas in a 3.50 m diameter sewer drain that was buried 8m below the roadway.

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FIRST IMPRESSION

Engineering Failure

Administrative failure

GUADALAJARA SEWER EXPLOSION

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THE TIMELINE

April 19, 1992

• Residents report strong smell of gas and presence of white smokes from the sewers.

April 21, 1992

• Workers from City Council and Protection Civil made revisions in Gante street.

• They announced that it is not necessary to evacuate the area even though they found strong levels of gas among other hydrocarbons.

April 22, 1992

• GUADALAJARA GAS EXPLOSIONS

April 25, 1992

• Strong smell of gas was still present, residents of the neighborhoods were instructed not to light any flames. Evacuation was undergoing.

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HOW DID IT REALLY HAPPENED?

Galvanic corrosion between galvanized iron(water pipeline) and reinforced steel(gasoline pipeline).

Followed by localized pitting on both materials. Diffusion of gas at higher pressure towards the sewage drain due

to the pressure and concentration gradient. Blocking of leaked gas at distinct sites within the sewage drain

due to the U-shaped sections in the sewage line. Pressure and temperature raised, flash point of gasoline was

reached and thus exploded.

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THE ROOT CAUSE Galvanic corrosion between water pipeline made of galvanized iron

and gasoline pipeline made of reinforced steel. Diffusion of gasoline into the sewage line through porous soil. The gasoline was directed to the sewage lines owing to the

gradients in concentration and pressure. Explosions took place at 10 different locations due to the gas-lock

occurred inside the sewage line.(The sewage line has to take the U shaped sections in order to accommodate the newly established suburban metro).

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CORROSION ON GASOLINE PIPELINE

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GAS ACCUMULATION IN THE SEWER LINE

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DAMAGE AFTER THE DISASTER

HUMAN CONSEQUENCES: 4500 disaster victims overall.

252 deaths 500 to 600 missing 1800 injured. 15000 people were left homeless.

MATERIAL CONSEQUENCES: 13 km. of streets heavily destructed. 1500 houses destroyed. 1224 buildings damaged 637 vehicles damaged Estimated monetary damage- $ 300 million to $ 1 billion.

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HOW IT COULD HAVE BEEN PREVENTED

Necessary consideration should have provided to the concern raised by citizens.

Effort had to be made in order to determine the cause and origin of the gasoline leakage.

Proper inspection and maintenance. Avoidance of interference between different fluid transportation

systems with different materials.

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SUGGESTIONS TO AVOID SIMILAR ACCIDENTS

Proper inspection and maintenance. Having detailed information about the geological features of the

ground and other pipeline systems already existing under ground before installation of a new pipeline system.

The labors involved in the actual installation process should at least have a fundamental knowledge about materials susceptible to corrosion and possibilities for material degradation.

Proper guidelines and quality measures should be implemented. Use of safety alarms working with reference to variation in

parameters such as pressure. Insulation of individual pipelines throughout its external surface area.

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CONCLUSION

• Significance of this incident.

• Impact on the normal engineering practices.

• Inference

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REFERENCES1. http://www.aria.developpementdurable.gouv.fr/wpcontent/files_mf/

FD_3543_guadalajara_1992_ang.pdf2. https://www.youtube.com/watch?v=odefOwa8XQ83. http://ubersicht.blogspot.com/2009/01/1992-explosion-in-

guadalajara.html4. http://www.history.com/this-day-in-history/sewers-explode-in-

guadalajara5. https://en.wikipedia.org/wiki/1992_Guadalajara_explosions6. https://www.youtube.com/watch?v=imxy-j1mlKw

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THANK YOU!!!