Geotechnical disasters and Seismic performance of lifeline systems during May 12th, 2008, Wenchuan earthquake

This paper gives a brief description of the relationship of geotechnical disasters and damage to the lifeline systems in the Wenchuan county, Sichuan province due to the strong earthquake invading (M=8.0) on May 12, 2008. Site investigation of geotechnical disaster and earthquake damage of main lifeline systems near the epicentre and main active seismic fault zone was conducted, and results were summarized as: (1) lifeline systems malfunction or completely failure is mainly attributed to geotechnical disasters. landslide, sink, debris and collapse are the important factors to damage the transportation and water-supply systems; (2) the intensive faulting movement was irresistible to the power-supply system, the pipeline system, bridge, highway, dam; (3) Seismic performance of some of lifeline systems under secondary disasters induced by geotechnical disasters, though elements of lifeline systems didn't occure any structure damage. (4) The damage of some elements of lifeline systems was affected by the site amplification of ground shaking and liquefaction due to poor local ground condition or landform. The investigation indicates that the high damage ratio of lifeline systems was found where geotechnical disasters are heavy. Some fitting designs of lifeline system have better earthquake resistance. This investigation also shows that reasonable site-selection is the most important step to mitigate the seismic risk or reduce seismic hazard in a great degree.