Saturday, December 22, 2007

Megastructures - The Akashi - Kaikyo Suspension Bridge

The Akashi Kaikyo Suspension Bridge is the longest suspension bridge in the world and it is probably Japan’s greatest engineering feat.

It took two million workers ten years to construct the bridge, 181 000 tonnes of steel and 1.4million cubic metres of concrete. The steel cable used would circle the world seven times.

It has six lanes and links the island of Awaji and the mainland city of Kobe, a distance of four miles. The concept of building a bridge across the Akashi Straits became urgent after a disaster in 1955. A ferry carrying over one hundred children sank after colliding with another ferry, in the busy shipping lane. One hundred and sixty eight children and adults died in the disaster. Political pressure for a bridge increased and in 1988 construction began.

The Akashi Straits is four miles wide at the bridge site with sea depths of one hundred metres and currents averaging fourteen kmph. The Akashi Straits is one of the busiest sea lanes in the world with over a thousand ships per day travelling through it. Furthermore, the bridge is in a typhoon region in which winds can reach speeds of 290 kmph.

The construction of a suspension bridge involves the use of two main cables stretching between two towers. The roadway beneath these is suspended by more cables. To stop the towers, roadway and cables collapsing, they are held at either end by large anchor blocks (the Akashi anchor blocks weigh 350 000 tonnes). In the case of the Akashi-Kaikyo Bridge, suspension bridge technology was pushed to the limit.

The Japanese designers and engineers tested their designs by building complex models. These were tested in wind tunnels which helped them refine the design so that the bridge could cope with severe weather and typhoon conditions. The photograph opposite shows 40 metre long model, set up for a variety of scientific tests.

After vigorous testing had taken place, construction of the real bridge could begin.


The two towers stand on two large circular foundations. The moulds for the two foundations were built in dry dock weighing 15 000 tonnes and 60 metres in height. In March 1989 a major stage of construction was reached with the moulds for the foundations to the towers being towed out to their positions in the sea by numerous tugs. When in position the moulds were flooded with two hundred and fifty million litres of water, taking eight hours to complete. By the time the moulds were full, they were resting on the sea bed.


Each of the two foundations were filled with 265 000 cubic metres of concrete. However, ordinary concrete does not mix with water and so the Japanese had to develop special concrete which was capable of mixing with sea water.

In 1989 work on the two towers began. Each is nearly as high as the Eiffel Tower and is designed to have a two hundred year lifespan. The towers are 283 metres in height and if the foundations are included, this adds a further 60 metres.
Each tower is made up of 90 sections and they were built with absolute precision as the design allowed only a 25mm offset at the top. In order to achieve this level of accuracy each of the blocks were ‘surface ground’ to a precise finish. 700 000 bolts were used to fix each of the towers together.
Each tower is designed to flex / move in storm force conditions. They and even have a special mechanism that counteracts and dampens movement.

When the towers were completed a temporary cable was stretched between both and a wire mesh gangway built so that workers could start construction of the main cables. This temporary gangway can be seen in the photograph to the right. Workers and machinery pulled the main cables from one tower to the other.

Once the main cables and the vertical cables were in position the deck / roadway was fixed hanging below them. This work took place in 1994. Large purpose built cranes were used to lift the sections, 4000 tonnes each, were bolted into position, one after another. 290 sections make up the entire bridge.
The photographs to the right show the cranes in operation and the deck as it was fixed in position, section by section.
Each section has a triangulated form. This means that weight is kept to a minimum and yet each section has maximum strength.

The final section of the deck was bolted in position in September 1998 and the bridge was opened to the public on the 5th of April of the same year.

51 comments:

Anonymous said...

"bolted in position in September 1998 and the bridge was opened to the public on the 5th of April of the same year."

So you're saying that the bridge was open to traffic before the deck was complete?

Interesting story, and fab pics, but the proofreading and formatting leave something to be desired, such as stating that the "pics to the right", when the images are actually 8-10 lines above and to the left.

slipstick said...

Seems very similar to the Mackinac Bridge, which was built when they were considering this one, if you ask me.

Anonymous said...

Thank you for the good writeup. It in fact was a amusement account it.
Look advanced to far added agreeable from you!
By the way, how can we communicate?
Feel free to visit my page - nudeteens

Anonymous said...

Excellent article. I absolutely appreciate
this website. Thanks!
Also see my web page :: free porn subscription

Anonymous said...

If some one wants to be updated with hottest technologies
after that he must be go to see this web page and be up to
date every day.
Feel free to surf my website : military porn

Anonymous said...

Thanks for sharing such a pleasant idea, article is nice, thats why i have read it fully
Also see my page - Orlando hookah

Anonymous said...

Great work! That is the kind of information that should be shared
around the internet. Disgrace on Google for now not positioning this put
up upper! Come on over and discuss with my web
site . Thank you =)
Feel free to surf my blog post - investors buying homes PA

Anonymous said...

Thank you for the good writeup. It if truth be told was a leisure account it.

Look complex to more brought agreeable from you!
However, how could we keep up a correspondence?
Also visit my website :: where can I find a total gym coupon

Anonymous said...

Malaysia & Singapore & brunei finest online blogshop for wholesale & quantity korean accessories,
earrings, earstuds, necklace, rings, bracelet, hair & trinket add-ons.

Deal 35 % wholesale discount. Ship Worldwide
my website: www.unemployment.ohio.gov

Anonymous said...

Malaysia & Singapore & brunei best on the internet blogshop
for wholesale & quantity korean add-ons, accessories,
earstuds, pendant, rings, hair, trinket & bangle add-ons.
Promotion 35 % wholesale price cut. Ship Worldwide
Also visit my blog ; brain fitness iPhone

Anonymous said...

Malaysia & Singapore & brunei finest internet blogshop for wholesale & supply korean add-ons, earrings,
earstuds, pendant, rings, bracelet, hair & bracelet accessories.
Offer 35 % wholesale rebate. Ship Worldwide
Also visit my homepage ; Baby Onesies

Anonymous said...

Fabulous, what a weblog it is! This website presents useful data to us, keep it up.
Here is my website : Oregon mortgage help

Anonymous said...

If you want to take a good deal from this post then you have to apply such methods to your won website.
Feel free to surf my web blog http://sedyk.blogspot.com/

Anonymous said...

Today, I went to the beach front with my kids. I found a sea shell and gave
it to my 4 year old daughter and said "You can hear the ocean if you put this to your ear." She placed the shell to her ear and screamed.
There was a hermit crab inside and it pinched her ear.
She never wants to go back! LoL I know this is completely off
topic but I had to tell someone!
Review my web page adrianne curry playboy

Anonymous said...

I'll right away grasp your rss as I can not to find your e-mail subscription link or newsletter service. Do you've any?
Please allow me know in order that I may just
subscribe. Thanks.
Here is my website ; accredited high school diploma

Anonymous said...

Hello! I know this is kind of off topic but I was
wondering which blog platform are you using for this website?
I'm getting sick and tired of Wordpress because I've had
issues with hackers and I'm looking at options for another platform. I would be fantastic if you could point me in the direction of a good platform.
Here is my weblog - http://prensadisidentepr.blogspot.co.uk/2007/03/top-50-soccer-goals.html

Anonymous said...

What's up, I want to subscribe for this web site to get latest updates, thus where can i do it please help.
Feel free to visit my homepage abused children caught on video

Anonymous said...

Someone essentially lend a hand to make critically articles I might
state. This is the first time I frequented your website page and so far?
I amazed with the research you made to make this particular put up
extraordinary. Great task!
Here is my website - hotmail .com or .net

Anonymous said...

I was suggested this blog by means of my cousin. I'm no longer sure whether this post is written through him as nobody else know such distinctive about my problem. You are wonderful! Thank you!
Also visit my web blog ; addictinggames.com solitaire

Anonymous said...

My family members all the time say that I am wasting my time here at net, however I know I
am getting know-how daily by reading thes nice articles or reviews.
My web site : best remodeling company orlando fl

Anonymous said...

Have you ever thought about including a little bit more than just your articles?

I mean, what you say is valuable and all. But think of if you added some great photos or videos to give your posts more, "pop"!
Your content is excellent but with images and clips, this website could certainly be one of the most beneficial in its niche.
Fantastic blog!
Here is my website : santa monica apartment

Anonymous said...

This paragraph offers clear idea in support of the new users of blogging, that
in fact how to do blogging.
Look at my site Discover More Here

Anonymous said...

Hi there would you mind letting me know which hosting company you're working with? I've
loaded your blog in 3 completely different browsers
and I must say this blog loads a lot faster then
most. Can you suggest a good web hosting provider
at a fair price? Kudos, I appreciate it!
My blog ... Hotmail.Es Ver Correo

Anonymous said...

Hi there to every one, it's in fact a fastidious for me to pay a quick visit this web page, it consists of precious Information.
My webpage : hotmail outlook express

Anonymous said...

I don't know whether it's just me or if perhaps everybody else
encountering problems with your blog. It appears as if some of the
text within your content are running off the screen.
Can somebody else please provide feedback and let me know if this is happening to them as well?
This could be a issue with my internet browser because I've had this happen previously. Kudos
Feel free to surf my webpage : search hotmail accounts

Anonymous said...

I'll right away grab your rss feed as I can not in finding your e-mail subscription hyperlink or e-newsletter service. Do you've any?
Kindly let me realize so that I could subscribe.
Thanks.
Also visit my web page : adding fractions and whole numbers

Anonymous said...

I was wondering if you ever thought of changing the structure of your website?

Its very well written; I love what youve got to say.
But maybe you could a little more in the way of content so people could connect with it
better. Youve got an awful lot of text for only having one or two pictures.
Maybe you could space it out better?
Look into my blog post - www.ohoy.com

Anonymous said...

Pretty element of content. I just stumbled upon your
web site and in accession capital to assert that I acquire in fact
enjoyed account your weblog posts. Any way I'll be subscribing on your feeds or even I fulfillment you get entry to persistently rapidly.
Feel free to visit my web page : abcdistributing shopping buynowpaylater

Anonymous said...

I quite like reading through a post that can make men and women think.
Also, many thanks for allowing for me to comment!
My weblog Adoption information

Anonymous said...

Hey, I think your website might be having browser
compatibility issues. When I look at your website in Ie, it looks fine but when
opening in Internet Explorer, it has some overlapping. I just
wanted to give you a quick heads up! Other then that, awesome blog!


Look at my website; aarp free games to play

Anonymous said...

WOW just ωhat Ι ωas looking for.
Camе heгe by seaгching foг buying a car ωith baԁ credit

Μy webpage - buying A car with poor credit

Anonymous said...

Similаr to the Ford Fiesta and thе Hοnda Fit,
thе new Focus іѕ ԁefinitely far more
ѕporty than the older mοdels. BMW's new i8 is a true sports car that just happens to also be a plug-in hybrid with great efficiency and a short electric-only range. Me, I wish I could take one of each, but what can I say.

Also visit my web site :: How to buy a car with bad credit

Anonymous said...



Here is my web page; cordyceps

Anonymous said...

If so, what are the top five slot machines for
sale questions you should ask to ensure that the homeowner makes all of the appliances and upgrades included.


Visit my web-site: slot machine distributor

Anonymous said...

If it is not a simple installing

my homepage professional roofing services

Anonymous said...

I гead this pοst fully about the dіfference of nеwest and prеviοus tеchnologіes, it's awesome article.

Here is my weblog ... hotmail.com

Anonymous said...

I do not even know the way I finished up right here, however I thought this post was once great.

I don't recognise who you might be but definitely you are going to a well-known blogger when you aren't already.
Cheers!

Feel free to surf to my page ... landing page design

Anonymous said...

Warts and skin tags grow on the pores and skin of your physique.
Skin moles are oval-formed, dim-colored spots that are generally little in dimension.


My webpage :: 2Dmm.Com

Anonymous said...

The belt could be worn wherever so you can get a fantastic function out taking
a cat nap or washing property.

Also visit my site Flex Belt Coupons

Anonymous said...

Howdy, There's no doubt that your web site may be having web browser compatibility issues. Whenever I take a look at your website in Safari, it looks fine but when opening in IE, it's got
some overlapping issues. I simply wanted to give you
a quick heads up! Apart from that, fantastic site!


my web-site; xxx movies

Anonymous said...

After checking out a handful of the blog articles on
your site, I really appreciate your way of writing a blog.

I saved as a favorite it to my bookmark website list and will be
checking back in the near future. Please check out my web site too and let me know how you feel.


My web site - http://www.xxxvideofix.com/video/145920/italian-porn-la-moglie-2.html

Anonymous said...

Hi! This is my first comment here so I just wanted to give a quick shout out and tell you I genuinely enjoy reading
your articles. Can you recommend any other blogs/websites/forums that
deal with the same subjects? Thanks a ton!

Here is my weblog - Deep anal in a threesome porn movie

Anonymous said...

Useful information. Lucky me I discovered your web site by chance, and I am shocked why this coincidence did not happened in
advance! I bookmarked it.

Also visit my homepage http://www.sexyhotgirlz.com/gorgeous-how-babe-cam-show-hd/

Anonymous said...

This is the perfect website for anybody who really wants
to understand this topic. You realize a whole lot its almost
tough to argue with you (not that I personally will need to…HaHa).

You certainly put a new spin on a topic that has been discussed for many years.
Excellent stuff, just excellent!

Here is my blog; reverse hotmail search

Anonymous said...

Hello, Neat post. There's an issue together with your web site in internet explorer, might check this? IE nonetheless is the marketplace chief and a large component to people will miss your magnificent writing because of this problem.

Check out my weblog - Teen Porn

Anonymous said...

It's not my first time to pay a quick visit this site, i am visiting this web page dailly and get good data from here everyday.

Feel free to visit my web site :: http://sexygirlchat.net

Anonymous said...

Chrysler and Jeep problem codes are two digit numbers.

Getting an OBD II scan device on the web shouldn't be a frightening working experience.

Check out my website - obd 2

Anonymous said...

I visited many sites however the audio quality for audio songs current
at this web site is really superb.

Have a look at my web blog ... nude party girls

Anonymous said...

I quite like looking through a post that will make people
think. Also, thanks for allowing me to comment!

Feel free to visit my page ... www.babesflick.com

Anonymous said...



Look at my web site - eben pagan accelerate Training

Anonymous said...

Hi Dear, are you really visiting this website on a regular
basis, if so then you will definitely take good
knowledge.

my web blog; oafishdock3409.newsvine.com