The National Freeway Bureau under the Ministry of Transportation and Communications has conducted an emergency inspection of National Highway No. 3 and a special taskforce will probe the cause of the April 25 landslide, officials announced April 27.
The NFB has listed 32 dip slopes as high alert zones. The Ministry of Transportation and Communications emphasized that preliminary visual inspections revealed no danger. The taskforce will be charged with determining the cause of the disaster and reviewing the maintenance of dip slopes. Its first progress report will be made April 30.
President Ma Ying-jeou directed the immediate formation of the taskforce April 27 by the Taiwan Professional Civil Engineers Association and the Ministry of Economic Affairs’ Central Geological Survey, to inspect and reinforce potentially dangerous sections of national highways to prevent any further hill collapses.
Among the 32 dip slopes along National Highway No. 3, there are nine each in the Keelung-Xizhi and Hsinchu stretches in the north, with others in the central Miaoli and Nantou sections and southern Chiayi, Tainan and Kaohsiung sections. Some dip slopes occur in the high traffic volume stretches near the Xihu and Nantou service areas.
The geology of most of the dip slopes consists of interbedded sandstone and shale, with some slopes at a width of around 100 meters, and others encompassing several kilometers.
Lien Shyi-ching, NFB chief engineer, said current maintenance procedures include daily inspections to check expansion joints, road surfaces and ground subsidence on slopes; focal inspections carried out every month or two in which engineers climb the slopes to check for movement in slope protection embankments and water diversion ditches; and special inspections in the wake of earthquakes or typhoons.
Yeh Kuang-shih, deputy MOTC minister, said the NFB has not detected any signs of slope slippage or damage to ground anchors in other areas in the course of its emergency inspections over the last two days. After the taskforce completes its work, any dangerous slopes will be further stabilized.
In related news, a “geology law” proposed by the CGS in 1996 has become a focus of attention following the highway landslide. CGS Director Lin Chao-chung called for the speedy adoption of the bill and the disclosure of geologically sensitive areas to prevent the reoccurrence of such tragedies.
The bill has been shuttled back and forth between the Legislature and Executive Yuan for over 10 years. Heavily promoted by the CGS after the major earthquake of Sept. 21, 1999, it passed its third reading in 2004, but more than 60 lawmakers called for reconsideration, preventing the completion of the legislative process.
The proposed bill conflicts with nearly 10 existing laws, including the Building Act, Highway Act, and Soil and Water Conservation Act, and would require geological safety assessment reports even for a farmhouse built on the farmer’s own land, making it virtually unenforceable, according to a former lawmaker who cosponsored the reconsideration.
Under the proposed law, the government would have to conduct a comprehensive geological survey and publicize the results, as well as specify “geologically sensitive areas” where construction would be restricted, in hopes of establishing a transparent, open mechanism making geological information available to the public and preventing related catastrophes.
An unnamed civil engineer said since freeways are government projects, those in charge can be identified and responsibility can be assigned. A geology law, however, would be a threat to the business of private construction firms. The saddest thing is that members of the public have no way of knowing whether their homes sit on dangerous land, the engineer noted. (THN)