Taiwan Freeway No. 3 landslide probe finds likely causes

Written by Randy Post (taken from http://geoprac.net/)

Wednesday, 13 April 2011 16:18

A panel of experts in civil engineering and geotechnical engineering has completed their investigation into the failure of the slope above Freeway No. 3 in Taiwan last April that killed 4 people. Their forensic geotechnical investigations concluded that the dip slope was already marginally stable. But they noted that they found corroded steel ground anchors that were part of the retaining system meant to restrain the slope. They conjecture that even though the contractor followed the relevant standards at the time of constructions, somehow voids formed around the cable during the grouting process and made the cable susceptible to corrosion. Also noteworthy is that as a result of this failure, Taiwan's National Freeway Bureau has changed standards for grouting ground anchors. They also conducted a comprehensive survey of all slopes along freeways and identified 32 slopes that were placed on a priority list for monitoring and inspection and 17 were found to need some form of mitigation. [Source: Taipei Times. Image: Sulekha.com]

Rock Slope Stability _ unstable rock treatment

from GeoPrac.net Monthly Newsletter #24 - 2011 April/May

http://geoprac.net/geonews-mainmenu-63/65-geologic-hazards/581-video-helicopter-based-rock-scaling-qsledgehammerq

There is a relatively new version of a video that came out in 2009 where the Norwegian Public Road Administration hired a helicopter to try to scale loose rock with a wrecking ball. This version has english subtitles explaining a few things, and also shows another technique they tried for scaling rock, water bombing!