Hsuehshan Tunnel

Hsuehshan Tunnel

Hsuehshan Tunnel East Entrance
Overview
Location	Taiwan
Coordinates	West Entrance: 24°56′18.96″N 121°42′54″E / 24.9386000°N 121.71500°E / 24.9386000; 121.71500 East Entrance: 24°50′52.08″N 121°47′27.6″E / 24.8478000°N 121.791000°E / 24.8478000; 121.791000
Status	Active
Start	Pinglin District, New Taipei City
End	Toucheng Township, Yilan County
Operation
Work begun	July 1991
Opened	June 16, 2006
Traffic	Road tunnel
Technical
Length	12.941 km (8.041 mi)
No. of lanes	4
Operating speed	60 to 90 km/h

The Hsuehshan Tunnel (Chinese: 雪山隧道; pinyin: Xuěshān Suìdào) or "Snow Mountain" tunnel, is the longest tunnel in Taiwan, located on the Taipei-Yilan Freeway (Taiwan National Highway No. 5). It opened on June 16, 2006.

The tunnel is bored through the Hsuehshan Range. The road connects Taipei through New Taipei to Yilan County, cutting down the journey time from two hours to just half an hour. It bypasses the rural district of Pinglin, which used to receive high traffic prior to the completion of the tunnel. One of the key aims of constructing the tunnel was to connect the western coast of Taiwan, where 95% of the population lives, to the eastern coast of the island and in doing so tackle the unbalanced development on the island. It is constructed with one pilot tunnel and two main tunnels for eastbound and westbound traffic. The total length is 12.942 km (8.042 mi), making the Hsuehshan Tunnel the ninth longest road tunnel in the world (fifth at the time of opening) and sixth longest in East Asia. The tunnel opened in June 2006 to severe traffic jams.

Tunnel construction began in July 1991 and took 15 years to complete and cost a total of NT$90.6 billion (US$2.83 billion) to complete. Tunnel construction used 370,000 m³ (13,000,000 cu ft) of concrete, 2,000 kilometres (1,200 mi) of cables, and 2,000 lighting units.

While excavating the tunnel, engineers encountered difficult geological problems like fractured rock and massive inflows of water, which caused severe delays. One of the three TBMs on the westbound tunnel was buried by a ground collapse. In order to speed up the tunnel boring, an additional working interface in Interchange Station No. 2 (under Ventilation Shaft No. 2) was built. Along the tunnel alignment, there are six major faults, ninety-eight fracture zones, and thirty six high-pressure groundwater sources. Hence, serious tunnel collapses with groundwater flooding took place periodically during tunnel construction. Altogether, 25 lives were lost during 15 years of construction.