The Los Angeles Times today covers the construction of the 141-mile stretch of the California high-speed rail from Bakersfield to LA's Union Station, and it can best be described with the following line: it's gonna be hard. The engineering required to get over the Tehachapi and San Gabriel Mountains is intense, with UC Berkeley professor Bill Ibbs calling the challenge "the project of the century." Here're a few things the 200-person team designing the bullet train's southern route is confronting: out of Bakersfield, one of the steepest sustained high-speed rail inclines in the world, above-ground viaducts will have to be as tall as 33-story skyscrapers, there will be tunnels 500 feet below the surface, plus there are a mishmash of fault lines. There are also the homes and businesses that will need to be purchased and demolished in the Mojave and in other areas like the San Fernando Valley (the train will cross the Valley before going underground near Glendale and reemerging in Chinatown on its way to Union Station).
Because of all the obstacles in the way of the train's route, nearly 59 percent of the 141 miles will require grade-separation through tunnels or viaducts--the energy required to run the train every day will be equivalent to a quarter of the Hoover Dam's average daily output. But the topography will be just as taxing, with an eight-mile long tunnel required under the Santa Clarita canyons. When it comes to earthquakes, a shut-down system would slow the trains during tremors and activate an emergency stop when a big shaker comes. For viaducts near fault lines, "engineers are considering reinforced concrete structures that would resist ground motion and have containment features to prevent a derailed bullet train from plunging to the ground."
The SoCal portion is expected to cost a bit over $20 billion and hopefully start work after the initial segment is built out in the Central Valley.
· Bullet train planners face huge engineering challenge [LA Times]