Force of a moving mass sridharan says ; then space structures moving mass at that speed; there is a designer to control Aazhither is that ; moving like force waves, swaying yet well balanced; and when the balance is shifted narrowly, force hammers. Baltimore bridge car travellers who went down are not spoken about. KR IRS 28324
---------- Forwarded message --------- From: Srinivasan Sridharan <[email protected]> Date: Thu, 28 Mar 2024 at 15:09 Subject: Re: Baltimore bridge wreck To: Rajaram Krishnamurthy <[email protected]> As a practicing structural designer for more than half a century , I can vouch say that the force from a moving mass of several thousand tons can even crush a cliff as large as a football field , not to mention a tiny pier supporting one side of a bridge! Sridharan. On Mar 28, 2024, at 11:14 AM, Rajaram Krishnamurthy <[email protected]> wrote: Will Baltimore bridge collapse force U.S. to pay more attention to its infrastructure? The Francis Scott Key Bridge will get rebuilt with federal funds, but many other structures across the nation aren’t getting the same support. An aerial view show large broken pieces of a bridges structure poking out of the water with a contianer ship of colorful cargo. Though thousands of active bridges in the U.S. are "structurally deficient" according to a report from the American Society of Civil Engineers, there's no evidence that the Francis Scott Key Bridge that collapsed Tuesday was one of them. Experts say that the cargo ship collision would've caused a collapse on even an ideally maintained bridge. March 26, 2024 The collapse of the Francis Scott Key Bridge in Baltimore is the latest example of a challenge to U.S. infrastructure amid a lack of funds and motivation to maintain aging bridges, experts say. The Baltimore bridge "is an old and reliable piece of infrastructure, that under almost any reasonable circumstances would be standing in another 20 or 30 years,” says Joseph L. Schofer, professor emeritus of civil and environmental engineering at Northwestern University's McCormick School of Engineering. “If you come along and pull out the primary support, there's no way to save the bridge.” Though he has no reason to believe negligence was involved in the Baltimore collapse, Schofer says some infrastructure catastrophes are. He points to the Fern Hollow Bridge failure in Pittsburgh as an example: The National Transportation Safety Board concluded reports and recommendations to fix corroded steel supports went ignored, ultimately leading to the collapse of the 447-foot-long bridge, which dropped a bus and four cars to the park below. It’s a disturbing trend as train derailments, highway and bridge collapses, and dam failures are being seen across the U.S, experts say. But which areas are civil engineers most concerned could cause imminent catastrophe, and what can we do about it? Physical collapse is happening now Federal funding will rebuild the Francis Scott Key Bridge, which more than 30,000 cars use daily. “In terms of where you go from here, you've got a bridge that's failed, and probably more likely, you want to rebuild it. So what are your options?" Schofer says. "Going forward, you’ve got some really interesting design options that could either make the likelihood of this kind of event very small or eliminated entirely, and I think probably that's what they'll do with a new design.” But many other key structures across the country aren’t getting the same attention. “There are cautionary tales all over,” says Maria Lehman, president of the American Society of Civil Engineers (ASCE) and vice chair of the Biden administration’s National Infrastructure Advisory Council. “Every county in the country has a list of bridges that, if they had money, they would replace tomorrow.” The 617,000 bridges in the U.S. include not just those spanning mighty rivers but also every highway overpass and minor link across a stream—and close to one tenth of them are significantly compromised. “If you have to think in terms of catastrophe, we’re already there,” says Amlan Mukherjee, the director of sustainability focusing on infrastructure at WAP Sustainability Consulting. In 2007, the collapse of an I-35W bridge in Minnesota killed 13 people and injured 145. More recently, a six-lane bridge over the Mississippi was closed for three months in 2021, disrupting interstate travel and shipping because an inspector missed a significant crack. Americans drive 178 million trips on structurally deficient bridges each day, according to the 2021 report from the ASCE. Yet the U.S. spends only 1.5 to 2.5 percent of its GDP on infrastructure, proportionately less than half of what the European Union spends, Lehman says. This long-term lack of funding has run out the clock on many solutions. Many U.S. bridges were built to last 30 to 50 years, but nearly half are at least half a century old. The average age of U.S. levees is also 50; dams average 57. The future of U.S. infrastructure Mukherjee is optimistic about the use of new technology to solve some of the country's infrastructure issues, though adoption has been slow. Drones can provide human inspectors with up-close views of areas they can’t reach themselves and reduce chance of human error; a drone on an unrelated project captured footage of the Mississippi bridge crack two years before its discovery. Bilal Ayyub, a professor of civil and environmental engineering at the University of Maryland, College Park, has also worked with North American freight railroads to find weak links using computer modelling. This can comb through thousands of stations to “identify exactly which point if it fails will have the biggest impact,” he says. K RAJARAM IRS 28324 -- You received this message because you are subscribed to the Google Groups "Thatha_Patty" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/thatha_patty/CAL5XZoroPcnrdmdbhjLmOe5uAho-Uxz7nh2uP_SgWSHcsXmn2A%40mail.gmail.com.
