Living with landslide: The ancona case history
|Location||International Geological Congress,oslo 2008|
|Author||Cardellini, Stefano; Osimani, Paolo|
|Holding Date||04 October 2008|
On 13th December 1982 an intense landslide involved Ancona city (Italy), affecting 11% of the urban area. It damaged private houses and infrastructures and about 3000 people were evacuated.
The railway and the main road were blocked, and the gas and water supplies were interrupted. Following the event, a seriesof geological investigations and analysis were performed in order to understand the landslide for mitigation purposes. The Ancona landslide has become one of the most studied landslide in Europe. This landslide is a complex deap-seated Landslide with overlapped sliding zones, of which the deepest is about 75m bgl.
The landslide body involves clay and silty-clay layers (pliocene-pleistocene), which are fractured and modified in the OC parameter, alternated with thin sand levels. The investigation and research has concluded that protection is impossible, both due to large expenses and for major environmental impact, which would have changed totally the site appearance.
Therefore, in order to guarantee the population safety, the Town Administration decided to establish a a comprehensive early-warning system. It is already installed a surface monitoring system based on 7 total stations and 33 geodetic GPS (7 references and 26 monitoring points). A borehole geotechnical system based on 3 DMS columns is going to be implemented.
The monitoring data are sent in real time through a WiFi standard HyperLan to the town Monitoring Center.
In this way, the Town Administration has chosen to "live with landslide": a new philosophy that implies that the security for the population is achieved through a high-quality and comprehensive early-warning system. This in contrast to the the more static concepts of standard engineering remediation work which is clearly impracticable in this case.