His philosophical reasons? T ey’re certainly lofty. Lin literally wanted to help bridge a global society, envisioning social and political peace. To promote a speaking engagement at the University of Buff alo in 1997, Lin spoke of combining philosophy with science. “My one unique capacity is I embody Chinese philosophical approach and deal with problems in a global manner. Basic science and technology I learned, especially from the West. I sort of put the two together.” But just how would he do it? Let’s take a look at Lin’s plans for both the Bering and Gibraltar Strait bridges.
Bering Strait: The Intercontinental Peace Bridge Peace was certainly a decisive motivator when Lin designed his Bering Strait Bridge that would link six continents. In 1968, the “cold war” arms race was a reality and Lin compared the cost of building a bridge (which he estimated at an incredibly frugal $4 billion at the time) to the $600 billion annual defense budgets of the U.S. and Russia. “T e mutual understanding generated by this cooperative undertaking would contribute to a decline in the arms race, so that the bridge cost could be justifi ed many times over. T e potentially positive impact on world peace makes its planning and construction a top priority worthy of further consideration.” By the 1990’s, Lin had changed his tactical tune. Even if peace was still his personal goal, he realized there was a stronger argument to make. Money. “I’ve switched to an economic front. You see, the bridge will cost
a few billion dollars. T e road on both sides will cost $50 billion. T e petroleum resources are worth trillions of dollars. But to get to the oil and gas you need roads. And you need the pipeline.”
CHALLENGES T e Bering Strait is a gap across time and space – specifi cally the International dateline and about 55 miles at its shortest distance – between Russia’s Siberia and the USA’s Alaska, just south of the Arctic Circle. Although the depth of the water is no more than 180 ft., and the currents aren’t described as severe – its arctic proximity brings other issues. Namely average daily lows of -4 degrees F that can plunge to -58 degrees F and long, very dark winters that would not be conducive to any kind of construction. As well, ice that can be 6 ft thick constantly fl oes for up to eight months of the year, creating a potential force of 5,000 short tons. Although the Alaska Earthquake Information Centre describes
the area as “aseismic” (surface displacement along a fault in absence of earthquakes), the area on the northern boundary of the Bering microplate is prone to seismic shifts.
“Often called the greatest structural engineer in the world, Lin pioneered the use of prestressed concrete, combining the tensile strength of steel with concrete’s resistance
to compression.” - Berkeley University’s Engineering Department
As well, the area is remote in the extreme – it’s 1,200 road-less, train-less miles on the Russian side, and not much better on the American, with 500 miles to the closest highway. Estimates to build any such highway have come in at about $5 million per mile.
In 1958, T.Y. Lin introduces the concept of constructing a bridge across the Bering Strait, known as the Intercontinental Peace Bridge.
30 MARCH-APRIL 2012 WIRE ROPE EXCHANGE
DESIGN According to a July/August, 1987 edition of PCI Journal, Lin designed his bridge to have three decks; the top deck for vehicles (weather permitting), a second level box for trains and the third lower box for the all important oil and gas pipes. T e bridge is comprised of two parts – the substructure and the superstructure. 220 precast, prestressed gravity piers would be constructed in one or two pieces - a double-curved cylindrical tower that could go a maximum of 180 feet under water and 80 to 200 feet above water that would be connected to a low base raft bottom slab. Each pier would be sized according to their position and depth of water in the Strait, curved in just the right spot to defl ect those nasty ice fl oes. Constructed in a dry basin before moving to a protected water site (off shore oil rig construction protocols), each pier would consist of about 25,000 cubic yards of concrete. A ballast is placed inside each pier for additional stability. By prefabricating the piers, both the raft and towers can be built at the same time, therefore shortening the construction time. Joined by post-tensioning, the raft and tower would be towed to their prepared foundations and sunk into position. T e total amount of concrete used in the substructure? 5,500,000
cubic yards. Mind you, that includes 20 pounds of pre-stressing tendons and 50 pounds of reinforcing steel in each yard.
T.Y. LiN INTERNATIONAl
T.Y. LiN INTERNATIONAl
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84