Beijing-Lhasa railway sinking

In spite of the benefit of being ruled by a "living Buddha," decades of planning and a cost of billions of dollars, parts of the Beijing-Lhasa railway, China's "engineering miracle," are sinking. Specifically, those sections where the project attempts to maintain stability atop the seasonal thawing and refreezing of the permafrost, according to Answers.com, engineers built "elevated tracks with foundations sunk deep into the ground, inserting vertical pipes that circulate liquid nitrogen and cold nitrogen gas into the ground, building hollow concrete pipes beneath the tracks to keep the rail bed frozen, and using metal sun shades."

On the failing cooling system, Gas World writes:

However, innovative as the idea is there are some signs that its application may be misplaced. The national news agency has reported that in some sections, the concrete in the rail bed has developed surface cracks, and foundations are sinking into the permafrost.

The Chinese Government have played down the potential problems and the Ministry of Railways Vice Minister, Song Yongfu has simply said that the ministry would take measures to deal with such difficulties.

So it would seem that with world temperatures on the rise, we can expect many years of expensive maintenance and instability for the world's most elevated, environmentally and otherwise sensitive railway.