Analysis of the pipe failures in the 2008 frozen-rain & snow, earthquake in China

Session 2A
2:40

Zhanjie Wang
Robin Bresser
Cindy Wang

The performance of utility pipelines for gas and water during natural disasters like earthquakes has always been of great concern. In 2008, two unexpected and extraordinarily serious natural disasters happened in China. The first was the unprecedented frozen-rain and snow calamity in January, covering 6 provinces of the southern China which were normally warm regions in winter; and the other was the earthquake on May 12th which measured 8.0 on the Richter scale, in Sichuan, in which over 80 000 people lost their lives.

Following these events investigations of pipe failures have been actively carried out in these areas. Results of water supply networks in some parts of Guizhou, gas distribution systems in Dujiangyan, and urban water supply in Mianzhu, Sichuan indicated that there was less damage to PE and ductile iron pipes than traditional pipes such as concrete pipes and gray cast iron pipes (CIP) which exhibited major failures. It was found that whilst the main reason for failure of the pipelines was due to the destructive power of the natural disasters other factors such as improper pipe materials, poor product quality and inappropriate installations also contributed.

Only a few failures were observed on the pipes with higher toughness which were correctly installed in good geological conditions and those recently installed. The results show that in order to improve the resistance of plastic pipes to natural disasters we should only use high quality pipe materials and improve the structural design. Therefore we need to enhance the product quality management and assist users in selecting those products and construct the installation in accordance with code requirements. Meanwhile we should continue to carry out the fundamental research of plastic pipes and propose new product testing methods to resist failures due to unexpected natural disasters.

Zhanjie Wang, Secretary-general, China Plastics Piping Association
Robin Bresser, Marketing Manager, Pipe, Borouge Pte Ltd.
Cindy Wang, Application Marketing Manager-Pipe, Borouge Hong Kong Ltd.