Has it been over three years? My last post is dated January 2009. I guess I have been busy, very busy, I moved, and I moved again but I seem to be in a position now where I can retake this blog.
My passion for bridges has not changed or diminished, I simply run out of time and energy and I have to prioritize.
Wednesday, April 25, 2012
Monday, January 26, 2009
Bridge collapse near Anegundi, India
There has been another tragic incident during the construction of a bridge. This time in India. Apparently a cable stayed bride over the Tungabhadra river failed during construction. There are several reports from different media organizations but at this stage the number of dead and injured workers and the cause of the incident have not been established.
From the photographs it looks as if it was a single tower asymetric, concrete deck cable stayed bridge and they were progressing on the erection of the main span
Photos were retrived from this website
Other report
There is never an acceptable excuse for something like this to happen!
From the photographs it looks as if it was a single tower asymetric, concrete deck cable stayed bridge and they were progressing on the erection of the main span
Photos were retrived from this website
Other report
There is never an acceptable excuse for something like this to happen!
Tuesday, January 20, 2009
Forth crossing preliminary design
It is a nice slender design. I am not very convinced about the single line of stays (torsional resistance of the deck and tower stability are issues) or the stays from two towers crossing in the middle (difficult to detail and construct) but it is good to see the project moving on.
From the BBC:
The design for the Forth replacement crossing is being worked on by the same firm responsible for the 'Bird's Nest' stadium at the Beijing Olympics 2008.
Engineering firm Arup was also responsible for the world's second longest spanning cable-stayed bridge, Stonecutter's Bridge in Hong Kong. Jacob the other half of the joint venture, was responsible for the design of the Clackmannanshire Bridge. Public exhibitions for the Forth crossing are being held on Tuesday.
The new bridge design is expected to have the longest central spans in the world for a multi-span cable-stayed bridge. It will also be the only long span cable-stay bridge in the world to have central crossed cables. These provide enhanced stiffness to the bridge structure, minimising the size of the central tower and creating a slim, elegant appearance.
The cables will run along the centre of the bridge. Transport Scotland is taking the Forth crossing exhibition to 12 different venues over two weeks to allow members of the public to view the plans for the crossing. Engineers and specialists from Transport Scotland and its consultants Jacobs Arup will be on hand to explain the work undertaken during 2008 to develop the strategy for the new crossing over the Forth and answer questions. It follows the ministerial announcement in December which confirmed that the Forth Replacement Crossing strategy will make use of the existing Forth Road Bridge as a public transport corridor.
The project is to be progressed via a Parliamentary Bill to be introduced towards the end of 2009. John Howison, Forth crossing interim project director, said: "This is an exciting project and we and our world class consultants are delighted to be working on it to produce a lasting visual landmark for the Forth."
Sebastian Tombs, Architecture and Design Scotland chief executive said: "We are encouraged by the strong vision so far demonstrated by the project team and their aspiration for high design quality. "We have warmly welcomed the proposed 'mono-tower' design for the new bridge."
From the BBC:
The design for the Forth replacement crossing is being worked on by the same firm responsible for the 'Bird's Nest' stadium at the Beijing Olympics 2008.
Engineering firm Arup was also responsible for the world's second longest spanning cable-stayed bridge, Stonecutter's Bridge in Hong Kong. Jacob the other half of the joint venture, was responsible for the design of the Clackmannanshire Bridge. Public exhibitions for the Forth crossing are being held on Tuesday.
The new bridge design is expected to have the longest central spans in the world for a multi-span cable-stayed bridge. It will also be the only long span cable-stay bridge in the world to have central crossed cables. These provide enhanced stiffness to the bridge structure, minimising the size of the central tower and creating a slim, elegant appearance.
The cables will run along the centre of the bridge. Transport Scotland is taking the Forth crossing exhibition to 12 different venues over two weeks to allow members of the public to view the plans for the crossing. Engineers and specialists from Transport Scotland and its consultants Jacobs Arup will be on hand to explain the work undertaken during 2008 to develop the strategy for the new crossing over the Forth and answer questions. It follows the ministerial announcement in December which confirmed that the Forth Replacement Crossing strategy will make use of the existing Forth Road Bridge as a public transport corridor.
The project is to be progressed via a Parliamentary Bill to be introduced towards the end of 2009. John Howison, Forth crossing interim project director, said: "This is an exciting project and we and our world class consultants are delighted to be working on it to produce a lasting visual landmark for the Forth."
Sebastian Tombs, Architecture and Design Scotland chief executive said: "We are encouraged by the strong vision so far demonstrated by the project team and their aspiration for high design quality. "We have warmly welcomed the proposed 'mono-tower' design for the new bridge."
Wednesday, December 10, 2008
Two killed in Kunming bridge collapse
Two people were killed and four others injured when a 200-meter section of a bridge that was undergoing demolition collapsed in Kunming, Yunnan province Tuesday evening.
An excavator and several workers were on the Xiaozhuang Bridge when the accident occurred at about 7:30 p.m., destroying a car parked under the bridge, Xinhua News Agency reported.
The injured victims are receiving treatment at a nearby hospital.
The bridge was located on an artery road linking the provincial capital and its northwestern parts.
From the China Daily webpage.
Obvioulsy the most critical moments for bridges are during construction, re-habilitation and demolition, when the structural system is either not complete or compromised.
Friday, November 21, 2008
Dubai smile bridge
A new bridge has been announced in Dubai. The seventh Dubai Creek crossing will be a signature bridge featuring an inverted arch. Preliminary name is the Dubai smile crossing.
I like bridges (obviously I love them enough to start a blog about them) but I have a problem with some signature bridges. I am an engineer and I tend to object to bridges that do not make sense structurally or in which form and shape supersede structural sense. Usually these bridges end up costing several times what a conventional bridge does, and they are a nightmare to design, construct and maintain.
This bridge seems to fall in that category. It looks 'spectacular', 'pretty', 'intriguing',... but it has little structural and engineering sense. I support beautiful bridge, I defend spending a bit more money and doing a good job rather than the run of the mill column/beam bridge, but there is a point now in which clients seem to want something 'different' every time and engineers/architects have to rake their brains to come up with structures that are less than optimal for the intended use.
For more details about the bridge see here and here.
I like bridges (obviously I love them enough to start a blog about them) but I have a problem with some signature bridges. I am an engineer and I tend to object to bridges that do not make sense structurally or in which form and shape supersede structural sense. Usually these bridges end up costing several times what a conventional bridge does, and they are a nightmare to design, construct and maintain.
This bridge seems to fall in that category. It looks 'spectacular', 'pretty', 'intriguing',... but it has little structural and engineering sense. I support beautiful bridge, I defend spending a bit more money and doing a good job rather than the run of the mill column/beam bridge, but there is a point now in which clients seem to want something 'different' every time and engineers/architects have to rake their brains to come up with structures that are less than optimal for the intended use.For more details about the bridge see here and here.
Thursday, November 20, 2008
Bridge collapse in Kashmir
Another tragic accident during bridge construction. It is feared that 23 workers died and many others were injured when a bridge collapsed in the Indian controlled Kashmir. The bridge is located near the border town of Uri, 92 km from Srinagar and the accident took place last Sunday November 16
There is very little information available and photos of the site have become public only a week after the accident was first reported.
This is probably another of those accidents that will never be fully understood. It is unforgivable and unjustifiable whenever something like this happens. There is no excuse or reason for people to die during the construction of a bridge.
No doubt people will question work practices and engineering on developing countries. Irrelevant if you ask me. There are more than enough accidents in developed countries, and nobody sets to build a bridge with the intention of killing anybody.
Whoever works on bridge construction knows that the possibility of a tragedy is always there. This is a dangerous industry and usually bridge stability is at its worse during construction. Half a bridge is usually less stable and more prone to failure than a complete bridge.
So, and considering that in the last few years more and more accidents and more tragic accidents seem to have occurred during bridge construction (or at least they have been more publicized), what can we do?
Maybe is time for somebody to come up with hard recommendations and standards to be followed during construction. There are guidelines and national practices, and obviously a responsibility from the construction company, but maybe what we need is a coordinated effort to put in place some short of guidelines to what we can refer. A kind of checklist to ensure that all issues have been considered and tragedies like this do not happen again
There is very little information available and photos of the site have become public only a week after the accident was first reported.
This is probably another of those accidents that will never be fully understood. It is unforgivable and unjustifiable whenever something like this happens. There is no excuse or reason for people to die during the construction of a bridge.
No doubt people will question work practices and engineering on developing countries. Irrelevant if you ask me. There are more than enough accidents in developed countries, and nobody sets to build a bridge with the intention of killing anybody.
Whoever works on bridge construction knows that the possibility of a tragedy is always there. This is a dangerous industry and usually bridge stability is at its worse during construction. Half a bridge is usually less stable and more prone to failure than a complete bridge.
So, and considering that in the last few years more and more accidents and more tragic accidents seem to have occurred during bridge construction (or at least they have been more publicized), what can we do?
Maybe is time for somebody to come up with hard recommendations and standards to be followed during construction. There are guidelines and national practices, and obviously a responsibility from the construction company, but maybe what we need is a coordinated effort to put in place some short of guidelines to what we can refer. A kind of checklist to ensure that all issues have been considered and tragedies like this do not happen again
NTSB preliminary report on the I-35W bridge collapse
The NTSB has released the preliminary report on the I-35 bridge collapse. The report is available on line at the NTSB website.
The report point out to a design or drafting error on the gusset plate design. The gusset was only half an inch thick instead of the one inch required. I think everybody should read it and reflect on the lessons we can learn.
The report point out to a design or drafting error on the gusset plate design. The gusset was only half an inch thick instead of the one inch required. I think everybody should read it and reflect on the lessons we can learn.
Thursday, November 6, 2008
Anothe bump on the road for the Thames Gateway Bridge project in London, UK. The story, taken from the Guardian Newspaper (incidentally one of my favourite British newspapers) indicates that the new London Mayor has scrapped the plans.
I see this more like a delay and not the final word because the bridge in question is actually required. Large infrastructures these days take a lot longer to achieve. Consultation processes and concerns about the environment, traffic increases, urban planning,... All these items, which, of course ought to be considered, tend to extend the planning process for years. While maintaining their function and validity, we should find a way to speed them up, so that projects are approbed, scrapped or modified accordingly to the public consultation process in a question of months or 1 to 2 years, rather than the 1 or 2 decades that some projects have been discussed so far.
Transport for London scraps plans for six-lane road bridge London Mayor Boris Johnson scraps scheme amid strong opposition from environmental campaigners
Boris Johnson, the London mayor, has shelved £3.5bn of transport schemes in the capital, including the Thames Gateway bridge, as part of multibillion-pound cost cuts. Johnson said today the move ended the "deception" of his predecessor, Ken Livingstone, who had ordered officials to draw up plans for the Thames Gateway project amid strong opposition from environmental campaigners.
"I am stopping the deception of keeping hopes alive when there is no funding for these schemes," said Johnson.
Other proposals taken off the drawing board today include the £1.3bn cross river tram; a £500m tram scheme for Oxford Street in the centre of the capital; and a £70m extension of the Docklands Light Railway to Dagenham.
The mayor also revealed plans to save £2.4bn in costs at Transport for London, including the loss of hundreds of jobs among TfL's 22,000-strong workforce.
The cost drive and sidelining of unfunded schemes were announced alongside an £80bn investment programme over the next decade. The programme includes bringing back the routemaster bus, upgrading the tube network and building the £16bn Crossrail underground link between Heathrow airport and east London.
"These cuts need to be seen in the context of the biggest investment in London transport for a generation," said Johnson.
Green campaigners welcomed the scrapping of the motorway-scale Thames Gateway road bridge as one of the most significant rejections of car traffic ever made.
The decision by TfL follows a year-long public inquiry which rejected the £450m bridge for environmental, social and economic reasons. The inquiry was to reopen next year after further pressure businesses.
"I have always been in favour of another crossing. But I don't think that this idea was the right one," said Johnson.
He said Transport for London would "look again" at proposals for a crossing at Silvertown, near London City Airport in Docklands. He argued the Thames Gateway area had sufficient transport links for the nearly 100,000 new homes that will be built there over the next decade.
Supporters of the bridge between Beckton and Thamesmead in east London argued it would reduce journey times and make east London a more attractive place for business. But evidence at the inquiry showed it would encourage car use, bringing more air and noise pollution and increasing carbon emissions.
The bridge was to pass through some of Britain's most deprived communities in east London, but leading transport analysts showed it would not bring regeneration to these areas.
Local resident groups joined national environment groups in welcoming the decision.
"This was not a local bridge for local people as it was billed. It was never designed to regenerate the area. It was just going to cause worse air and noise pollution," said Jacqui Wise, coordinator of the Action Group Against the Bridge.
Jenny Bates, London campaigns coordinator for Friends of the Earth, said: "This was an ill-conceived and outdated attempt to regenerate an area with road-building and would have blighted the area and led to more traffic, congestion and climate change.
"It would have brought terrible problems for some of the most deprived communities in Britain. We must find better ways of helping east London.
" It was the second time in 12 years that business interests had tried but failed to get a major Thames crossing built. In 1993, the proposed east London river crossing, which would have would destroyed Oxleas wood, one of London's last remaining areas of ancient woodland, was dropped after similar local opposition.
Darren Johnson, a Green member of the London assembly, said: "Scrapping this six-lane new road across the Thames is good news for the environment and for the local people who have spent years fighting this proposal. It was the single biggest mistake of the previous mayor, who spent £30m of taxpayers' money preparing a traffic-generating monster."
The Thames gateway bridge was first proposed in 1996 by Stephen Norris when he was transport minister in the last Conservative government. In a remarkable reversal, Norris was instrumental in having the bridge scrapped — he now sits on the TfL board that ruled against it.
Johnson pledged to scrap the bridge in his election manifesto this year but supports the need for an extra river crossing in the east of London.
Jannette Graham, a resident of the Windsor Park estate in Beckton which would have been within 50 metres of the bridge, said: "We are ecstatic. People here, who are largely ethnic communities and do not have a political voice, have had far too much noise and pollution already. This is a victory for the people. It makes a whole heap of difference around here."
Taken from the Guardian newspaper on line
I see this more like a delay and not the final word because the bridge in question is actually required. Large infrastructures these days take a lot longer to achieve. Consultation processes and concerns about the environment, traffic increases, urban planning,... All these items, which, of course ought to be considered, tend to extend the planning process for years. While maintaining their function and validity, we should find a way to speed them up, so that projects are approbed, scrapped or modified accordingly to the public consultation process in a question of months or 1 to 2 years, rather than the 1 or 2 decades that some projects have been discussed so far.
Transport for London scraps plans for six-lane road bridge London Mayor Boris Johnson scraps scheme amid strong opposition from environmental campaigners
Boris Johnson, the London mayor, has shelved £3.5bn of transport schemes in the capital, including the Thames Gateway bridge, as part of multibillion-pound cost cuts. Johnson said today the move ended the "deception" of his predecessor, Ken Livingstone, who had ordered officials to draw up plans for the Thames Gateway project amid strong opposition from environmental campaigners.
"I am stopping the deception of keeping hopes alive when there is no funding for these schemes," said Johnson.
Other proposals taken off the drawing board today include the £1.3bn cross river tram; a £500m tram scheme for Oxford Street in the centre of the capital; and a £70m extension of the Docklands Light Railway to Dagenham.
The mayor also revealed plans to save £2.4bn in costs at Transport for London, including the loss of hundreds of jobs among TfL's 22,000-strong workforce.
The cost drive and sidelining of unfunded schemes were announced alongside an £80bn investment programme over the next decade. The programme includes bringing back the routemaster bus, upgrading the tube network and building the £16bn Crossrail underground link between Heathrow airport and east London.
"These cuts need to be seen in the context of the biggest investment in London transport for a generation," said Johnson.
Green campaigners welcomed the scrapping of the motorway-scale Thames Gateway road bridge as one of the most significant rejections of car traffic ever made.
The decision by TfL follows a year-long public inquiry which rejected the £450m bridge for environmental, social and economic reasons. The inquiry was to reopen next year after further pressure businesses.
"I have always been in favour of another crossing. But I don't think that this idea was the right one," said Johnson.
He said Transport for London would "look again" at proposals for a crossing at Silvertown, near London City Airport in Docklands. He argued the Thames Gateway area had sufficient transport links for the nearly 100,000 new homes that will be built there over the next decade.
Supporters of the bridge between Beckton and Thamesmead in east London argued it would reduce journey times and make east London a more attractive place for business. But evidence at the inquiry showed it would encourage car use, bringing more air and noise pollution and increasing carbon emissions.
The bridge was to pass through some of Britain's most deprived communities in east London, but leading transport analysts showed it would not bring regeneration to these areas.
Local resident groups joined national environment groups in welcoming the decision.
"This was not a local bridge for local people as it was billed. It was never designed to regenerate the area. It was just going to cause worse air and noise pollution," said Jacqui Wise, coordinator of the Action Group Against the Bridge.
Jenny Bates, London campaigns coordinator for Friends of the Earth, said: "This was an ill-conceived and outdated attempt to regenerate an area with road-building and would have blighted the area and led to more traffic, congestion and climate change.
"It would have brought terrible problems for some of the most deprived communities in Britain. We must find better ways of helping east London.
" It was the second time in 12 years that business interests had tried but failed to get a major Thames crossing built. In 1993, the proposed east London river crossing, which would have would destroyed Oxleas wood, one of London's last remaining areas of ancient woodland, was dropped after similar local opposition.
Darren Johnson, a Green member of the London assembly, said: "Scrapping this six-lane new road across the Thames is good news for the environment and for the local people who have spent years fighting this proposal. It was the single biggest mistake of the previous mayor, who spent £30m of taxpayers' money preparing a traffic-generating monster."
The Thames gateway bridge was first proposed in 1996 by Stephen Norris when he was transport minister in the last Conservative government. In a remarkable reversal, Norris was instrumental in having the bridge scrapped — he now sits on the TfL board that ruled against it.
Johnson pledged to scrap the bridge in his election manifesto this year but supports the need for an extra river crossing in the east of London.
Jannette Graham, a resident of the Windsor Park estate in Beckton which would have been within 50 metres of the bridge, said: "We are ecstatic. People here, who are largely ethnic communities and do not have a political voice, have had far too much noise and pollution already. This is a victory for the people. It makes a whole heap of difference around here."
Taken from the Guardian newspaper on line
Wednesday, November 5, 2008
Bridges to prosperity
Sometimes we get marvel at the ingenuity and drive that allows us to make wonderful, new bridges. The longest, the highest, the widest, the most sophisticated bridges. We plan them, we design, build and maintain them. It is a sign of pride, and so it should.
However, bridges are born from one of the most basic human needs for communication. And there are places in the World in which that need is not covered.
Enter Bridges to Prosperity. This is a charity that tries to 'change lives one bridge at a time'. I encorage anybody and everybody to get involved with them and help.
However, bridges are born from one of the most basic human needs for communication. And there are places in the World in which that need is not covered.
Enter Bridges to Prosperity. This is a charity that tries to 'change lives one bridge at a time'. I encorage anybody and everybody to get involved with them and help.
Tuesday, November 4, 2008
Mostly Bridges
Well
It has been 10 days and 12 posts since I started the Mostly Bridges blog and, although I am still learning the ropes and trying to decide what I want to make of the blog, I am generally satisfied with the results. I have asked a couple of friends and colleagues to check the blog and the feedback has been generally positive, although the word 'enginerd' has been mentioned.
Why the blog? Not sure yet, really, but I keep bumping into information and news and bits and pieces about bridges, and I keep wanting to share them with other people and give my opinion. I thought that this would be a good medium.
Hopefully Mostly Bridges will be around for a while, hopefully I will have the time to keep posting at regular intervals and hopefully, somebody will find the content at least slightly amusing.
It has been 10 days and 12 posts since I started the Mostly Bridges blog and, although I am still learning the ropes and trying to decide what I want to make of the blog, I am generally satisfied with the results. I have asked a couple of friends and colleagues to check the blog and the feedback has been generally positive, although the word 'enginerd' has been mentioned.
Why the blog? Not sure yet, really, but I keep bumping into information and news and bits and pieces about bridges, and I keep wanting to share them with other people and give my opinion. I thought that this would be a good medium.
Hopefully Mostly Bridges will be around for a while, hopefully I will have the time to keep posting at regular intervals and hopefully, somebody will find the content at least slightly amusing.
Tercer Milenio Bride in Zaragoza, Spain
Zaragoza just hosted the 2008 International Exposition, with Water and sustainable water use as the main theme. Since the city is on the south shore of the Ebro River, and the main Expo grounds were on the north shore, a couple of bridges were built before the event in order to improve communications. The Bridge Pavilion designed by Zaha Hadid was one of them, and I will reserve my opinion for a future post, the other one was the "Puente del Tercer Milenio" or Third Millennium Bridge (celebrating the city's ancient history).
This bridge is spectacular. It is a white concrete arch bridge with a 216 m main span. It has a beautiful shape and clean lines. The bridge was designed by Juan Jose Arenas, Spanish bridge designer (who incidentally was my Bridge I and Bridge II professor at university, but that is material for another blog). Mr. Arenas has designed several bridges, and I recommend a quick visit to the website of his company (do not worry, there is an English version).
I think that Mr. Arenas truly understands the arch shape and how to create some iconic bridges. One criticism is that this bridge is a scaled copy of one of his previous works, La Barqueta Bridge, for the 1992 World Exposition in Sevilla, Spain. I think that is a very valid comment. I would like to hear his opinion on it.
Apart of some photographs, I have included a couple of schematic drawings for the bridge, so that you can appreciate the scale and some of the details.
This bridge is spectacular. It is a white concrete arch bridge with a 216 m main span. It has a beautiful shape and clean lines. The bridge was designed by Juan Jose Arenas, Spanish bridge designer (who incidentally was my Bridge I and Bridge II professor at university, but that is material for another blog). Mr. Arenas has designed several bridges, and I recommend a quick visit to the website of his company (do not worry, there is an English version).
I think that Mr. Arenas truly understands the arch shape and how to create some iconic bridges. One criticism is that this bridge is a scaled copy of one of his previous works, La Barqueta Bridge, for the 1992 World Exposition in Sevilla, Spain. I think that is a very valid comment. I would like to hear his opinion on it.
Apart of some photographs, I have included a couple of schematic drawings for the bridge, so that you can appreciate the scale and some of the details.
Sunday, November 2, 2008
Strait of Gibraltar - Bridge or tunnel
The Gibraltar Strait is one of those remaining crossings anchored in legend for which a link has been discussed for centuries. For me, it is not a question of 'if' but of 'when' and 'how'.
A bridge crossing has been discussed several times. There is a particular article, by T.Y. Lin ("Gibraltar Straight Crossing - A challenge to bridge and structural engineers") that proposes a modified suspension bridge arrangement. This is probably the most famous scheme.
Although the article by T.Y. Lin says that the bridge is feasible with current bridge engineering knowledge and techniques, the truth is that it would be quite the undertaking, and probably not the best engineering solution.
The Spanish and Moroccan governments seem to agree with this. Following an agreement in 1979, in 1980 both governments established an agreement that saw the creation of twin organizations in Spain and Morocco to investigate the feasibility and progress in the construction of a permanent link between the two countries.
Although a bridge alternative was investigated, it was abandoned for a immersed tunnel alternative due to the following factors:
Obviously I would prefer a bridge over a tunnel, but given the current technologies in both bridge and tunnel construction, and given the characteristics of the project, I have to agree that, at least by now, a tunnel solution seems to be the best.
A bridge crossing has been discussed several times. There is a particular article, by T.Y. Lin ("Gibraltar Straight Crossing - A challenge to bridge and structural engineers") that proposes a modified suspension bridge arrangement. This is probably the most famous scheme.
Although the article by T.Y. Lin says that the bridge is feasible with current bridge engineering knowledge and techniques, the truth is that it would be quite the undertaking, and probably not the best engineering solution.
The Spanish and Moroccan governments seem to agree with this. Following an agreement in 1979, in 1980 both governments established an agreement that saw the creation of twin organizations in Spain and Morocco to investigate the feasibility and progress in the construction of a permanent link between the two countries.
Although a bridge alternative was investigated, it was abandoned for a immersed tunnel alternative due to the following factors:
- Higher projected costs
- Technological uncertainty
- Interference with ship traffic and risk of impact
- Higher ecological impact
- Inability to phase the project in function of expected traffic increases
Obviously I would prefer a bridge over a tunnel, but given the current technologies in both bridge and tunnel construction, and given the characteristics of the project, I have to agree that, at least by now, a tunnel solution seems to be the best.
Wednesday, October 29, 2008
Bridge Articles in the Civil Engineering Magazine
The ASCE (American Association of Civil Engineers) has a magazine, the Civil Engineering Magazine. It is published monthly, and although not fully available on line, they allow access to past issues' feature articles. The 2008 February issue contained a good article on the New Tacoma Narrows bridge. I quite enjoyed reading it.
The other article that interested me on the magazine, is on the March 2007 issue, about the Penobscot Narrows Bridge, Maine. The article focuses on a new technology for cable stayed bridges in which the strands are not anchored on the tower or pylon. Instead they are continuous through the tower.
Obviously this system has the advantage to allow for much more slender towers, and from the article you would imagine that it is the best thing since sliced bread. I am not fully convinced. First of all, I think that construction has to be more complicated although the article indicates otherwise. The same for as cable adjustment. and replacement. I do not fully visualise the advantages over the traditional system. Also, cable configurations have to be balanced on both sides of the tower, third, the strand loading and fatigue behaviour have to 'suffer'. Strands do not like being bent, and fatigue issues always appear on those areas.
I do not know if this system is so new neither. Years ago, while visiting Alga, I saw them testing precisely a saddle design for cable stays. They were trying to determine their fatigue behaviour. I never found out the results of those tests.
Although the first modern suspension bridges were built in the United States, they had not built any suspension bridge of significance for quite a while until the beginning of this decade, with the Carquinez Suspension Bridge first and now with the New Tacoma Narrows Bridge.
The other article that interested me on the magazine, is on the March 2007 issue, about the Penobscot Narrows Bridge, Maine. The article focuses on a new technology for cable stayed bridges in which the strands are not anchored on the tower or pylon. Instead they are continuous through the tower.
Obviously this system has the advantage to allow for much more slender towers, and from the article you would imagine that it is the best thing since sliced bread. I am not fully convinced. First of all, I think that construction has to be more complicated although the article indicates otherwise. The same for as cable adjustment. and replacement. I do not fully visualise the advantages over the traditional system. Also, cable configurations have to be balanced on both sides of the tower, third, the strand loading and fatigue behaviour have to 'suffer'. Strands do not like being bent, and fatigue issues always appear on those areas.I do not know if this system is so new neither. Years ago, while visiting Alga, I saw them testing precisely a saddle design for cable stays. They were trying to determine their fatigue behaviour. I never found out the results of those tests.
Eleven dead in SW China crane accident
There has been a serious accident in a bridge in China. The Furongjiang Bridge near Chongquing, in southwest China, is under construction and there was an accident in which 11 workers were killed and 12 injured. There is very little information available, but it seems that a container carrying the workers was moved by a 'crane" when one of the lines broke and the container fell.
From the available photos it would appear that the bridge had a high line system to crane materials and workers on the site. High line systems are used wherever conventional crane access is not practicable. So most likely it was not a crane but the system what failed and caused the accident. The container (second photograph) does not look much more than an old skip.
Whenever I find about any such accident, my mind starts racing, thinking about what the possible causes were and how I am going to prevent anything similar from happening on any job I am involved with. Unfortunately accidents do happen however, bridge construction is a dangerous business!
There are several news reports on this accicent. This one is the best.
Whenever I find about any such accident, my mind starts racing, thinking about what the possible causes were and how I am going to prevent anything similar from happening on any job I am involved with. Unfortunately accidents do happen however, bridge construction is a dangerous business!
There are several news reports on this accicent. This one is the best.
Memorial Bridge Demolition
The old Memorial Bridge in North Dakota is currently been demolished after a new bridge replaced it. The three spans were blown with explosives in two separate operations, on October 6 and October 29. The website has very interesting information and videos of the explosive demolition.
It certainly looks like a lot of fun and very spectacular. I was surprised about how close the new bridge is (apparently closed to traffic during the procedure) and how well the operation went. I can only guess at the amount of engineering involved, certainly not trivial.
It certainly looks like a lot of fun and very spectacular. I was surprised about how close the new bridge is (apparently closed to traffic during the procedure) and how well the operation went. I can only guess at the amount of engineering involved, certainly not trivial.Tuesday, October 28, 2008
Structural Database
When I am looking for more information about a specific bridge, there is a database of structures that I use as a first point of contact, it is called Structurae, and it is amazingly complete. It not only includes bridges, but also buildings, dams, towers, tunnels, ... It is available in English, French and German, searchable, and it includes a wealth of information, from who the designer or contractors are, to photographs and articles related to each structure.
I highly recommend a visit and its use to find out more details about a specific structure. If there are any drawbacks to the site, it can be a bit slow at times. Otherwise, 10 out of 1o
I highly recommend a visit and its use to find out more details about a specific structure. If there are any drawbacks to the site, it can be a bit slow at times. Otherwise, 10 out of 1o
Monday, October 27, 2008
Load tests
In Spain load tests on bridges are mandatory after construction and prior to opening to traffic. The tests are designed to, obviously, ensure that abridge is capable of supporting the required live load, but also to ensure it is behaving as planned. This is achieved by measuring deflections during the test and comparing them to expected values.
This first photograph shows the load test carried out on the Serreria Bridge in Valencia. While the second photograph corresponds to the Viaduct over the Turia river for a high speed railway line. My understanding is that the test will be repeated with trains once the rails and electrical supply are installed.
Obviously load tests imply extra costs, but I think that they are a very prudent measure on bridges of new construction and there is merit to the idea of implementing them on other countries. I have no experience, and I would love to hear from somebody who has been involved on them.
Winning design unveiled for new Tarleton bridge
A WINNING design has been selected for a new bridge to cross the River Douglas through a local beauty spot.
The bridge will cross the river at the old railway bridge point between Hesketh Bank in West Lancashire and Much Hoole in South Ribble.
It will be a landmark feature of the Ribble Coast and Wetlands Regional Park the bridge will provide an alternative crossing point to the A59 at Tarleton.
The successful entry from London-based JDA Architects with Arup was chosen from 110 entries in an international competition organised by the Royal Institute of British Architects.
West Lancashire people had their say on which bridge was selected when the seven short-listed designs were displayed at public consultation meetings in September.
Lancashire County Council will now work with other organisations involved in the scheme to get funding for the bridge.
In total 271 consultation feedback forms were received, with considerable support for the winning design.
People’s views were taken into consideration by the jury panel, which included representatives from Lancashire County Council, West Lancashire District Council, South Ribble Borough Council and the North West Regional Development Agency.
Matthew Tomlinson, Cabinet Member for Sustainable Development said: "Although the proposal is still at a very early stage this crossing represents a great opportunity to develop sustainable transport links in the area by allowing people to visit this unique part of the region without using the car."
Once built the bridge will provide a link for people wishing to travel and explore West Lancashire and South Ribble on foot, by bicycle and on horseback.
Bob Allen from the Ribble Coast and Wetlands Regional Park said: "The River Douglas bridge will be a crucial gateway opening up sustainable access to the internationally recognised wildlife habitats within the Regional Park."
From the Southport Visitor
Pitt River Bridge project marks milestone
PITT MEADOWS, BRITISH COLUMBIA — The Pitt River Bridge and Mary Hill Interchange Project marked a milestone today as it reached the two-thirds completion mark, announced British Columbia Premier Gordon Campbell, the Honourable James Moore, federal Secretary of State (Asia-Pacific Gateway) (2010 Olympics) (Official Languages), and British Columbia's Transportation and Infrastructure Minister Kevin Falcon.
"The Pitt River Bridge Crossing is a significant gateway for British Columbia and it's particularly important to the people of Maple Ridge, Pitt Meadows and surrounding communities," said Premier Campbell. "Traffic over the Pitt River Bridge has almost tripled since 1985 and, with the new Golden Ears Bridge opening, more growth will follow. This new bridge and interchange will significantly improve safety and reliability along this rapidly growing transportation corridor by allowing traffic to flow more smoothly."
"The Pitt River crossing connects key economic and transportation facilities with the Greater Vancouver Area," said Secretary of State Moore. "This investment demonstrates the federal government's commitment to facilitating Canada's trade with the Asia-Pacific region while minimizing its impact on the communities through which it must move."
The Pitt River Bridge and Mary Hill Interchange Project includes a new seven-lane bridge that will replace the existing swing bridges, as well as an interchange to replace the current Lougheed Highway and Mary Hill Bypass intersection. The design incorporates more than $8.5 million in pedestrian and cycling features, including bicycle lanes across the new bridge. The design also allows for one lane to be added in the future. The additional lane could meet future demand for vehicle use or light rail rapid transit and could be used for high-occupancy vehicles and RapidBus in the interim.
The existing intersection at Lougheed Highway and Mary Hill Bypass will be replaced with a grade-separated interchange with on- and off-ramps that would allow for the free flow of traffic. In combination with the new bridge, these improvements will allow for the elimination of the current counterflow system.
"Hitting this milestone shows us just how far we've come on this important project," said Minister Falcon. "Construction is on schedule and within budget, and we can see the excellent results, including pile driving, deck panel placement and cable installation. When the new bridge opens in 2009, it will not only boost safety and ease traffic congestion, it will also have positive economic and environmental benefits for the entire region."
On February 9, 2007, the provincial and federal governments announced a cost-sharing agreement for the $198-million project. The Province of British Columbia is providing $108 million, and the Government of Canada is providing up to $90 million through the Asia-Pacific Gateway and Corridor Initiative.
The Pitt River Bridge and Mary Hill Interchange Project received environmental certification in July 2006. The new bridge is slated to open in late 2009. A comprehensive traffic management plan is in place to ensure construction proceeds with minimal traffic disruptions.
On October 11, 2006, Prime Minister Stephen Harper announced the Asia-Pacific Gateway and Corridor Initiative, a $1-billion federal initiative. In two years, the Government of Canada has partnered with British Columbia and other western provinces, municipalities and the private sector to announce strategic infrastructure projects worth nearly $2.5 billion, including federal contributions of over $900 million.
The Asia-Pacific Gateway and Corridor Initiative brings together infrastructure, policy, governance and operational issues in an integrated, multimodal, public-private strategy to strengthen Canada's competitive performance in international commerce with the Asia-Pacific region.
Given its strategic location linking the CP Intermodal Terminal and Lower Mainland ports, the Pitt River Bridge and Mary Hill Interchange Project is a critical component of the Gateway Program. The province's $3-billion Gateway Program will improve roads and bridges for people, goods and transit throughout Metro Vancouver. The Gateway Program is divided into three projects: Port Mann/Highway 1; South Fraser Perimeter Road; and the Pitt River Bridge and Mary Hill Interchange project.
From Canada News Centre
Robinson Bridge - Collapse during construction
More than a dozen people have been injured after a bridge under construction collapsed Monday afternoon.
Officials say 14 construction workers received minor injuries, including broken bones as they were pouring concrete. Authorities say the bridge's support structure, which may have been up to 30 feet high, collapsed. Some of the workers rode the debris down to the ground, officials say. All workers have been accounted for. None of the injuries are life threatening.
Authorities are worried that there could be additional collapses due to the impact from the first collapse. The Occupational Safety and Health Administration is investigating as well as the Idaho Transportation Department. "We are relieved that no one was seriously hurt by this accident," said Pamela Lowe, Idaho Transportation Department director. "We will begin immediately to work with the contractor to learn what happened."
Work started in late September to replace the I-84 overpasses at Robinson Boulevard and Black Cat Road as part of the I-84 widening project from Meridian to Nampa. Work on both bridges has been suspended pending an investigation. Graham Construction and Management of Spokane is the contractor on this $8.5 million project to rebuild the bridges.
From www.2news.tv
Officials say 14 construction workers received minor injuries, including broken bones as they were pouring concrete. Authorities say the bridge's support structure, which may have been up to 30 feet high, collapsed. Some of the workers rode the debris down to the ground, officials say. All workers have been accounted for. None of the injuries are life threatening.
Authorities are worried that there could be additional collapses due to the impact from the first collapse. The Occupational Safety and Health Administration is investigating as well as the Idaho Transportation Department. "We are relieved that no one was seriously hurt by this accident," said Pamela Lowe, Idaho Transportation Department director. "We will begin immediately to work with the contractor to learn what happened."
Work started in late September to replace the I-84 overpasses at Robinson Boulevard and Black Cat Road as part of the I-84 widening project from Meridian to Nampa. Work on both bridges has been suspended pending an investigation. Graham Construction and Management of Spokane is the contractor on this $8.5 million project to rebuild the bridges.
From www.2news.tv
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