Damages to Transport Facilities by Rainfall Induced Landslides During November 2009 in Nilgiris, India

摘要

Nilgiris district, a renowned hill station in the state of Tamilnadu, India, has a history of damaging landslides. This paper presents field observations and results of preliminary geotechnical investigations on the damages to infrastructure due to rainfall induced landslides during November 2009, which left more than fifty people dead and hundreds homeless. Laboratory tests were conducted on soil samples collected from landslide locations. The soils are of clayey sand and silty sand type with high fine content and low permeability. Case studies of damages caused to roads, railways and buildings are presented. Though the immediate triggering factor for the landslide at many locations was heavy intense rainfall, there were several causal factors like excavation of slope at toe, vertical cutting, loading at crest and defective maintenance of surface drainage systems.