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แวะมาทักทายค่ะน้องกบ

ขอให้ปฎิบัติและเจริญในธรรมยิ่งๆ ขึ้นไปค่ะ

แวะมากราบนมัสการและแสดงความยินดีครบรอบ 1 ปีค่ะ

สวัสดีค่ะ อ.รุจิเรศ

คิดว่าการเอาคานไปวางบนต้นไม้คงไม่ทำร้ายต้นไม้หรอกค่ะ ภาพที่เห็นน่าจะเป็นส่วนหนึ่งของบ้านต้นไม้ (ภาพด้านล่าง) ใช้ิวิธีทาบกิ่งรอบต้นไม้อีกที คิดว่าไม่ได้เจาะค่ะ เขามีต้นไม้หลายต้นช่วยรับน้ำหนักจากคานเหล็กเหล่านี้อีกทีหนึ่ง ไม้ยืนต้นส่วนใหญ่แข็งแรงทีเดียวค่ะ รับน้ำหนักต่างๆ ได้ดี

ขอบคุณอาจารย์ที่แวะเข้ามาให้ข้อคิดเห็นและเยี่ยมชมนะคะ

กราบนมัสการท่านพระปลัด

งานยุ่งอยู่พอสมควรค่ะ จังหวะเขียนไม่ค่อยมี พอกลับบ้านก็ไม่ค่อยได้เข้าเน็ต ก็เลยไม่ได้เขียนเสียนาน เรื่องธรรมะก็ไม่ค่อยได้เขียนในช่วงนี้ กำลังคิดๆ อยู่แต่ยังไม่มีโอกาสลงมือเีขียนค่ะ

ขอบคุณที่พระคุณเ้จ้าเข้ามาเยี่ยมเยียนนะคะ

สวัสดีค่ะอ.ขจิต

แหะๆ สงสารเหรอคะ พี่ว่าดีกว่าตัดต้นไม้มาทำบ้านนะ ^ ^

คิดว่าเขาคงไม่ได้เจาะมันหรอกค่ะ แต่ให้มันโตรอบๆ คานนะค่ะ

ขอบคุณสำหรับข้อมูลและภาพนะคะ สวยดี แต่อยู่สูงมากทีเดียวนะคะ

ทำได้สวยงามและแข็งแรงดีทีเดียวค่ะ ^ ^

สวัสดีค่ะคุณแสงแห่งความดี

ถ้ามีผู้เริ่มทำให้เกิดความยั่งยืน (sustainability) ไม่ว่าจะเป็นในด้านใดที่จะทำให้เราอยู่ร่วมกับธรรมชาติที่เป็นผู้ให้ได้ดีกว่านี้ ก็ยินดีทั้งนั้นเลยค่ะ ตัวเองก็พยายามเริ่มทำบ้างนิดๆ หน่อยๆ เริ่มจากตัวเราก่อน แต่เรื่องบ้านต้นไม้แบบนี้ยังไม่ได้ทำค่ะ ยังไม่มีโอกาส แต่ก็คิดๆ ไว้ค่ะ

ขอบคุณสำหรับข้อคิดเห็นนะคะ

สวัสดีค่ะคุณครูอ้อย

สบายดีค่ะ ดูท่าทางครูอ้อยกับหลานก็สบายดีมากๆ เลยนะคะ น่ารักจังค่ะ

ขอบคุณที่แวะมาทักทายนะคะ ^ ^

สวัสดีค่ะคุณตุ๊กตา

ความคิดเห็นส่วนตัวคิดว่าคงไม่เป็นการทำร้ายต้นไม้หรอกค่ะ เขาคงเลือกใช้ไม้ยืนต้นที่มีความแข็งแรงพอสมควร เดาว่าในภาพแรกคงเป็นการทาบกิ่งต้นไม้รอบคานไม่ได้ใช้วิธีเจาะรูต้นไม้ค่ะ

ขอบคุณที่แวะมาเยี่ยมชมและสำหรับข้อคิดเห็นนะคะ

ขอบคุณคุณธีรเดชที่แวะเข้ามาเยี่ยมชมและให้ข้อคิดเห็นนะคะ

สวัสดีค่ะอ.wwibul

น่าเสียดายนะคะที่สิ่งเหล่านี้หายไปเรื่อยๆ นึกบรรยากาศที่อาจารย์เล่าไว้ออกเลยค่ะ คงจะเป็นบรรยากาศที่น่าอยู่มากๆ

คนในอดีตมีจังหวะชีิวิตที่ช้ากว่าในยุคปัจจุบัน เวลาทำอะไรๆ ก็มักจะละเมียดละไมและคิดหน้าคิดหลังก่อนเสมอ (แหะๆ ตอนนี้เริ่มจะเป็นคนแก่ คิดช้าลงและละเอียดขึ้นเหมือนกันค่ะ ^ ^)

ยุคนี้มันยุคจานด่วน ทุกอย่างต้องรอพร้อมเสริฟกับความต้องการที่ไม่มีสิ้นสุดของคน ของทุกวันนี้มันเลยขาดรายละเอียด ทำให้เร็ว ทำให้มาก เน้น optimization เพื่อคนหมู่มากไว้ก่อน มันก็เลยเป็นแบบนี้แหละค่ะ ได้แต่วางชีวิตตัวเองให้มีจังหวะชีิวิตที่ช้าลงไว้บ้าง จะได้ไม่เหนื่อยไปโดยเปล่าประโยชน์อะไร ^ ^

ขอบคุณอาจารย์ที่แวะเข้ามาให้ข้อคิดเห็นค่ะ

สวัสดีค่ะอ.วสวัตฯ

ดีใจเหมือนกันค่ะ (ฮา)

จังหวะเหมาะ มีโอกาสและอ่านเจอเรื่องน่าสนใจพอดี ^ ^

ขอบคุณสำหรับกำลังใจนะคะ

และขอบคุณที่มาเยี่ยมชมอย่างรวดเร็วค่ะ ^ ^

Productivity Report Calls For Integrated, Efficient Approach

07/29/2009

A widespread adoption of lean techniques, integrated teaming and virtual design and construction could be the keys to improving productivity in the construction industry, according to a new report released by the National Research Council. The report, “Advancing the Competitiveness and Efficiency of the U.S. Construction Industry,” focuses on reducing waste in time, cost, materials, energy, skills and labor and offers recommendations on how to promote industry-wide adoption over the next 20 years.

Source: U.S. Dept. of Commerce, Bureau of labor statistics
Construction and non-farm labor productivity index

“This is the most important topic in the industry right now, but it’s one that has continued to falter, and ultimately no one does anything substantive about it,” says Pat Galloway, CEO of Pegasus-Global Holdings in Cle Elum, Wash., and a member of the committee that oversaw the study.

Productivity has been a hot-button issue in recent years, particularly following a 2004 analysis by Dr. Paul Teicholz of Stanford University. It suggested that construction labor productivity declined by nearly 20% between 1964 and 2003, while other non-farm industries improved by more than 200%.

Drawing from three white papers and a two-day workshop with industry experts, the committee homed in on five connected approaches that represent “opportunities for breakthrough improvements” in efficiency over the next two to 10 years. Among the techniques promoted in the report are greater use of prefabrication, preassembly, modularization and offsite fabrication, as well as widespread use of interoperable technology, such as building information modeling.

Greater integration between team members is also listed as an opportunity to improve jobsite efficiency through effective interfacing of people, process, materials, equipment and information.

Although many such approaches have gained momentum in recent years, they’ve yet to reach critical mass, some experts say. Kevin Bredeson, director of virtual construction at Providence, R.I.-based Gilbane Building, says his company has seen high return on investment in projects that use building information modeling.

“New England is our largest region by revenue, and yet it is farther behind than most areas in adoption [of BIM],” he says. “That keeps us from being fully integrated on every project and realizing even better results… It’s a major cultural shift getting so many of these industry veterans to not fight change.”

David Morris, director of virtual construction at Norwalk, Conn.-based­ EMCOR Group and chair of the BIM Forum’s Subcontractors Subforum, says BIM’s cost of entry remains a barrier.

“A smaller guy that pays list price could rack up $40,000 in hardware and software costs,” he says. “Add in [other factors and] you’re in over $100,000 quickly. For a five- to six-man shop that does $5 million to $10 million in revenue per year, it’s tough to bite that off.”

The report also called on the National Institute of Standards and Technology, which commissioned the NRC study, to gather industry stakeholders to develop a collaborative strategy for implementing the highlighted approaches.

“As long as we’re all pulling in the same direction, the more people, the better,” says Deke Smith, executive director of the buildingSMART alliance that was formed to address these issues.

The report also suggests that NIST work with federal bureaus to develop a “technology readiness index” for innovations with high risk, cost and impact.

Huw Roberts, global marketing director at Exton, Pa.-based technology provider Bentley Systems, believes that NIST is well positioned to create such standards, but he warns that a rating index could be difficult to develop.

The “definition of readiness,” Roberts says, could be very fluid depending on the objectives that are being sought.

Study Finds Branding Top Use Of Social Networking Tools

07/29/2009

Construction industry firms and individuals who use social networking face confusion both about how to use the tools and how to measure success, according to research rolled out last month at the Society for Marketing Professional Services’ Build Business conference.

How Firms Use Social Networking
Source: Society for Marketing Professional Services Foundation; based on Zoomerang® social networking survey of 576 members, conducted January 2009

Funded by SMPS Foundation, the open Internet-based survey was conducted between Jan. 30 and Feb. 15, netting 371 complete and 205 partial responses from SMPS members. Some respondents clearly confused electronic social networking with going to conferences or other offline networking events, says Barbara Shuck, vice president of marketing for Emc2 Group Architects Planners, Mesa, Ariz., one of the co-authors of the white paper “Social Networking for Competitive Advantage.”

Firms that use blogs, LinkedIn (linkedin.com), Facebook (facebook.com) and Twitter (twitter.com) use them primarily for marketing individual professionals (62%), firms (50%) and, to a lesser degree, for employee recruitment (20%) and retention (7%), the study found.

The largest factor preventing AEC firms from using social media is lack of understanding of what it is and how it works, the study says. Still, understanding and use are soaring as current users spread the word and sites get more coverage by media. LinkedIn reportedly has more than 40 million users and Facebook more than 250 million. Twitter doesn’t release statistics but clearly is growing exponentially. Shuck sees social media growing among members as well. “Our study is already out of date,” she says.

One firm that embraces social networking is HOK . Despite presence on LinkedIn, Facebook, Twitter, YouTube, Flickr, Delicious and VisualCV, “I think we haven’t even scratched the surface of its potential,” says Mike Plotnick, media relations manager in St. Louis. Four corporate communications staffers manage the social media sites and engage about 30 staffers worldwide as HOK bloggers on hoklife.com. Plotnick and his colleagues are aware they may be ahead of their time, but he says social media already has helped HOK win some business.

The tone of the conference, which drew 600 people July 16-18 in Las Vegas, was cautious but not grim. “We do hear of firms that are hiring, especially in business development,” says SMPS President-elect Thomas E. Smith Jr., president of BonTerra Consulting, Pasadena, Calif.

SMPS now has 58 chapters, including three new ones in the U.S. and its first international chapter in Ontario, Canada. It conducts seven regional conferences, as well as the annual national conference, with an eighth planned in 2010, says SMPS President Dana Birkes, vice president at The Flintco Cos., Tulsa, Okla. And, SMPS has a presence on LinkedIn, Facebook and Twitter.

สวัสดีจ้าน้องสาว

แวะเข้ามาทักทายแต่ไม่ได้รู้เรื่องเพลงนี้เท่าไหร่เลย เปิดฟังแบบสะดุดๆ เพราะเป็นพวกความเร็วต่ำมาแป๊บนึงแล้วก็เลิก ได้ฟังนิดๆ ว่าเพราะดีอยู่ : )

อนุโมทนา

ขอให้กุศลผลบุญและการปฏิบัิติของน้องหมอส่งผลให้เกิดความสำเร็จตามใจหวังด้วยค่ะ

เห็นด้วยมากๆ

"อยากพ้นทุกข์ ไม่อยากต้องมาเวียนว่ายตายเกิดอีก......."

กราบนมัสการหลวงพี่มหาชัยวุธ

เพิ่งได้เข้ามาเห็นบันทึกและไปสอบถาม อ.ศิริศักดิ์ มาอีกทีค่ะ

อ.ศิริศักดิ์บอกว่าถ้าบ่อลึก 10 เมตรนั้นใช้ปั้มหอยโข่่งทั่วไปไม่ได้ เพราะลึก 10 เมตรนั้นมีความแตกต่างของแรงดันอากาศ (pressure) มากไป  อาจารย์แนะนำว่าต้องใช้ปั้มจุ่ม หรือปั้มแช่ (submersible pump) ซึ่งมีหลายขนาดด้วยกัน ถ้ากำลังน้อยก็อาจจะส่งน้ำได้อ่อนหรือไม่ถึง ลองถาม spec จากร้านค้าค่ะ spec เครื่องจะระบุว่าส่งน้ำขึ้นได้สูงกี่เมตร เมื่อส่งน้ำขึ้นมาแล้วสามารถใช้ปั้มหอยโข่งส่งน้ำไปยังจุดอื่นๆ หลังจากได้น้ำมาจากปั้มจุ่มแล้วค่ะ

เมื่อครู่ลองค้นๆ ปั้มแช่กับปั้มดูดน้ำลึกในเน็ตดู พบว่ามีหลายแบบหลายอย่างให้เลือกค่ะ เห็นว่ามีปั้มดูดน้ำลึกได้ถึง 25-30 ม.ด้วยค่ะ ลองดูนะคะ

กราบนมัสการค่ะ

 

 

เพิ่มเติม link ข้อมูล เรื่องกรอบมาตรฐานคุณธรรมจริยธรรมที่ Siamturakij.com

ตนได้ลงนามในประกาศกระทรวงศึกษา ธิการว่าด้วยกรอบมาตรฐานคุณวุฒิระดับอุดมศึกษาแห่งชาติ ที่ให้การจัดการศึกษาระดับอุดมศึกษาตั้งแต่ปริญญาตรีถึงปริญญาเอกต้องมี มาตรฐานตามที่กระทรวงศึกษาธิการจะจัดทำรายละเอียดตามออกมาภายหลัง เพื่อเป็นหลักประกันและนำไปสู่การผลิตบัณฑิตที่มีคุณภาพ โดยมอบหมายให้สำนักงานคณะกรรมการการอุดมศึกษา (สกอ.) จัด ประชุมกับผู้ทรงคุณวุฒิในทุกสาขาวิชา เพื่อร่วมกันจัดทำมาตรฐานคุณวุฒิในแต่ละสาขาวิชา ซึ่งหลังจากจัดทำเสร็จและประกาศใช้แล้ว ทุกมหาวิทยาลัยจะต้องปรับปรุงการจัดการศึกษาในแต่ละสาขาวิชาของตัวเองให้ เป็นไปตามมาตรฐานคุณวุฒินั้นภายในปี 2557

“กรอบมาตรฐานคุณุวฒิดังกล่าว จะเดินหน้าไปสู่การสร้างบัณฑิตที่มีคุณภาพ โดยมีคุณลักษณะ 5 ด้าน คือ มีคุณธรรม ซึ่งเป็นเรื่องสำคัญสุด เพราะผลสำรวจของสถาบันต่างๆ สะท้อนให้เห็นชัดว่า คุณธรรมของคนไทยลดลง ล่าสุดผลวิจัยของม.มหิดล ระบุว่า คุณธรรมคนไทยทุกกลุ่มลดลงโดยเฉพาะด้านความซื่อสัตย์ลดจาก 2.76 ในปี 2550 เหลือ 2.34 ในปี 2552 เพราะฉะนั้น มหาวิทยาลัย จะต้องเดินหน้าไปสู่การผลิตบัณฑิตที่มีความรู้คู่คุณธรรมให้ได้ นอกจากบัณฑิตต้องมีคุณธรรมแล้ว อีก 4 ด้านที่เหลือ จะต้องมีความรู้ ทักษะทางปัญญา ทักษะทางสังคม และทักษะการใช้เทคโนโลยีต่างๆ โดยเฉพาะเทคโนโลยีสารสนเทศ ซึ่งมีบทบาทมากในโลกยุคโลกาภิวัตน์”

2 to plead guilty in Big Dig concrete case

- AP Legal Affairs Writer

Published: Wed, Jul. 08, 2009 03:53PM

Modified Wed, Jul. 08, 2009 03:53PM

BOSTON -- Two former managers of a Big Dig contractor pleaded guilty Wednesday to being part of a conspiracy to deliver substandard concrete to the massive highway project.

Six former managers of Aggregate Industries NE Inc. were indicted in 2006 on charges they falsified records to hide the inferior quality of more than 5,000 truckloads of concrete.

They were accused of recycling concrete that was too old or already rejected by inspectors and in some cases double-billing for the loads.

Gerard McNally, a former quality control manager, and Keith Thomas, a former dispatch manager, pleaded guilty to 12 charges, including 2 conspiracy counts, five mail fraud counts and five counts of filing false reports in connection with a federal highway project.

A prosecutor said in court Wednesday that as part of their plea agreements, both McNally and Thomas have agreed to cooperate against the other four men and will testify against them during their trial, which is scheduled to begin Monday in U.S. District Court.

The men who are going on trial are: John Farrar, of Canterbury, Conn., a former dispatch manager; Robert Prosperi, of Lynnfield, a former general manager; Marc Blais, of Lynn, a former dispatch manager; and Gregory Stevenson, of Furlong, Pa., former district operations manager.

Laywers for McNally and Thomas would not comment on their plea agreements. Sentencing was scheduled for Oct. 1.

In 2007, Aggregate pleaded guilty to fraud and agreed to pay a $50 million settlement to end civil and criminal investigations into substandard concrete it delivered to the project. Under the settlement, Aggregate was allowed to avoid debarment, a sanction that would have barred the company from bidding on state and federal contracts.

Formally called the Central Artery and Third Harbor Tunnel project, the Big Dig buried Interstate 93 in tunnels beneath downtown and connected the Massachusetts Turnpike to Logan Airport with a third tunnel beneath Boston Harbor.

The $15 billion Big Dig - considered the costliest highway project in U.S. history - was plagued by construction problems, leaks, falling debris and huge cost overruns.

On July 2006, Milena Del Valle and her husband were driving through an Interstate 90 connector tunnel when 26 tons of concrete ceiling panels crashed onto their 1991 Buick, crushing to death the 39-year-old mother of three.

But the case against Aggregate was never connected to this crash.

The NTSB's July 2007 accident report said the wrong type of adhesive was used to secure the concrete slabs in the tunnel ceiling, and the Massachusetts Turnpike Authority contributed to the accident by failing to implement a timely tunnel inspection program.

As Unbreakable as ... Glass?

Sally Ryan for The New York Times

A CLEAR VIEW A project lets visitors see all angles from the 103rd floor of the Sears Tower in Chicago. Builders are experimenting with new materials and methods to expand the use of glass in construction. More Photos >

Published: July 6, 2009

CHICAGO — To truly appreciate how glass can be used structurally, make your way to 233 South Wacker Drive in downtown Chicago. More precisely, make your way 1,353 feet above South Wacker, to the 103rd floor of the Sears Tower.

Once there, take a few steps over to the west wall, where the facade has been cut away. Then take one more step, over the edge.

You’ll find yourself on a floor of glass, suspended over the sidewalk a quarter-mile below. If you can’t bear looking straight down past your feet, shift your gaze out or up — the walls are glass, too, as is the ceiling. You’ve stepped into a transparent box, one of four that jut four and a half feet from the tower, hanging from cantilevered steel beams above your head. The glass walls are connected to the beams, and to the glass floor, with stainless-steel bolts. But what’s really saving you from oblivion is the glass itself.

The boxes, which opened last week as part of an extensive renovation of the tower’s observation deck, are among the most recent, and more outlandish, projects that use glass as load-bearing elements. But all glass structures have at least a bit of daring about them, as if they are giving a defiant answer to the question: You can’t do that with glass, can you?

You can. Engineers, architects and fabricators, aided by materials scientists and software designers, are building soaring facades, arching canopies and delicate cubes, footbridges and staircases, almost entirely of glass. They’re laminating glass with polymers to make beams and other components stronger and safer — each of the Sears Tower sheets is a five-layer sandwich — and analyzing every square inch of a design to make sure the stresses are within precise limits. And they are experimenting with new materials and methods that could someday lead to glass structures that are unmarked by metal or other materials.

“Ultimately what we’re all striving for is an all-glass structure,” said James O’Callaghan of Eckersley O’Callaghan Structural Design, who has designed what are perhaps the world’s best-known glass projects, the staircases that are a prominent feature of some Apple Stores.

Through it all, they’ve realized one thing. “Glass is just another material,” said John Kooymans of the engineering firm Halcrow Yolles, which designed the Sears Tower boxes.

It’s a material that has been around for millennia. Although glass can be made in countless ways to have any number of specific uses — to conduct light as fibers, say, or serve as a backing for electronic circuitry, as in a laptop screen — structural projects almost exclusively use soda-lime glass, made, as it has always been, largely from sodium carbonate, limestone and silica.

“For years, the basic composition of soda-lime glass has not changed much,” said Harrie J. Stevens, director of the Center for Glass Research at Alfred University. It’s the same glass, more or less, that is used for the windows in your home and the jar of jam in your fridge — and that old elixir bottle you bought at an antique store.

It’s basic stuff, but far from simple. “Of course, glass is an unusual material,” said James Carpenter of James Carpenter Design Associates, who has designed glass facades and other structures and was a consultant for the glassmaker Corning in the 1970s. “Since we don’t really know what it is.”

Although there has long been debate as to whether glass is a solid or liquid, it is now usually described as an amorphous solid (there is no evidence that it flows, extremely slowly, over time as a liquid). The noncrystalline structure is achieved by relatively rapid cooling below what is referred to as the glass transition temperature, around 1,000 degrees Fahrenheit for the soda-lime variety.

Cooled further and cut, pristine glass is very strong. But like a new car that plummets in value the moment it is driven off the lot, glass starts to lose its strength the instant it’s made. Tiny cracks begin to form through contact with other surfaces, or even with water vapor and carbon dioxide.

“If you take the freshly made surface and blow on it with your breath, you’ve reduced the strength of glass by a factor of two,” said Suresh Gulati, a mechanical engineer and self-described “strength man” who retired in 2000 after 33 years at Corning but still works for the company as a consultant.

Even one gas molecule can break a silicon-oxygen bond in glass, generating a defect, said Carlo G. Pantano, a professor of materials science at Pennsylvania State University. While glass is very strong in compression, tensile stresses will make these tiny fissures start to grow, bond by bond. “That’s what makes glass break,” Dr. Pantano said. “And if it doesn’t break, it weakens it.”

Protective coatings are one way to avoid new cracks, although they can affect transparency, which is the main reason for using glass in the first place. Changing the glass recipe can also make it harder for cracks to form and propagate. “There is some evidence that you can modify the composition to make it innately stronger,” Dr. Stevens said, although that risks altering other properties or making the glass too costly. (And glass projects are not cheap to start with; the glass in the Sears Tower project cost more than $40,000 per box.)

The manufacturing process can be modified, too, to keep the surfaces of the glass as pristine as possible. In one technique, used for laptop glass, molten glass is pumped into a V-shaped trough, spills over on both sides and flows down the outside of the V, joining together at the bottom into a sheet that continues to move downward as it cools. This way, each side of the sheet is a “melt surface,” exposed only to the air and not touched by any part of the equipment.

For structural purposes, glass is often strengthened the old-fashioned way — by tempering. This puts the surface under compression, so that even more tensile force is needed for cracks to grow.

For flat glass, heat tempering is most often used. William LaCourse, a professor at Alfred, said the process took advantage of one property of glass — that when it cools slowly it becomes denser. By rapidly cooling the exterior of a sheet (usually with air), the surface stays less dense. “Inside it’s still hot, and tries to cool to a more dense structure,” Dr. LaCourse said. “This pulls the surface into compression.”

In chemical tempering, sodium ions in the surface are replaced with potassium ions, which are about 30 percent larger. It’s like taking a suitcase full of summer-weight clothes and replacing the top layer with winter-weight items; the suitcase will bulge at the seams when you try to close it. Glass cannot bulge at the seams, so the surface becomes compressed.

Tempered glass may take longer to crack, but it can still break. Because surface compression must be balanced by interior tension, when tempered glass does break it forms many more smaller pieces than untempered glass, as more fracture lines release more energy. “The more it is strengthened the more pieces it will fly into,” Dr. Gulati said. An extreme example of this is a Prince Rupert’s drop, a small glass ball with a long tail formed by dropping molten glass into water. You can pound on the ball end with a hammer and it will not break, but snip off the tail and the ball will explode into tiny pieces as the tensile forces are released.

In structural applications, breaking into smaller pieces is often preferred, because these have less chance of causing injury. But tempering alone is usually not enough.

A primary concern when building with glass is what happens if and when a component breaks — what engineers call “post-failure behavior.” Unlike steel or other materials, glass does not deform or otherwise give advance warning of failure. If breakage occurs, maintaining the integrity of the structure is paramount so that people on or below it are safe.

That’s where lamination comes in. In a typical project, glass sheets (one-half-inch thick in the Sears Tower project) are bonded with thin polymer interlayers. The interlayers add strength and, should one of the glass layers break, keep the structure together, and the pieces from falling.

But lamination makes fabricating glass for structural uses very difficult. Since cutting into tempered glass causes it to break, each sheet must be polished and drilled for the connecting fittings before it is tempered. Tolerances are extremely small, to avoid potentially destructive stresses in the assembled structure.

“It’s doable,” said Lou Cerny of MTH Industries, who managed the installation at the Sears Tower, where the tolerances were one-sixteenth of an inch. “There’s just not a lot of people who want to get involved in it.”

No wonder, then, that those who build with glass look forward to a day when their structures will be unencumbered by metal or other materials.

“My goal has always been to reduce the amount of fittings in glass,” said Mr. O’Callaghan, whose Apple staircases use stainless steel and, occasionally, titanium to join the glass components.

Already, some engineers are using different glass shapes to reduce the dependence on metal. Rob Nijsse, a professor at the Delft University of Technology in the Netherlands and a structural engineer with the firm ABT Belgium, has used large sheets of corrugated glass, mounted vertically, for window walls in a concert hall in Porto, Portugal, and a museum being built in Antwerp, Belgium. The shape helps stiffen the glass against wind loads.

Other designers think about using different kinds of glass. “There are so many amazing types of glass available,” Mr. Carpenter said. “There’s an enormous potential to transfer some of their characteristics into architectural uses.”

Using a glass that does not expand much when heated, for example, would enable components to be welded together, forming, in effect, a continuous piece of glass. Conventional soda-lime glass expands too much, so welding introduces stresses that can lead to failure.

Researchers at Delft have experimented with welding glass components. But low-expansion glass is much costlier than soda-lime glass.

Other engineers are starting to use adhesives to join glass directly to glass. Lucio Blandini, an engineer with Werner Sobek Engineering and Design in Stuttgart, Germany, used adhesives to create a thin glass dome, 28 feet across, for his doctoral thesis in a clearing in Stuttgart. “I think adhesives are the most promising connection device,” Dr. Blandini said. “It allows glass to keep its aesthetic qualities.” His firm is using adhesives in parts of structures being built at the University of Chicago and in Dubai.

But the long-term strength and reliability of adhesives has not been proved, so most people who work in glass think an all-glued structure is a long way off.

“We have way too many lawyers in this country,” said Mr. Cerny, the installer at the Sears Tower. “It’ll be awhile before we see that.”

July 7, 2009

Soil conditions investigated as cause of Shanghai apartment building collapse

SHANGHAI

A nearly finished 13-story apartment building in Shanghai toppled over because of piles of dirt that were excavated to build an underground parking garage, according to initial investigation results, experts say.

City officials vowed to pursue responsibility for the June 27 disaster, which killed one person and cast doubt on the safety of the scores of other projects under way in this city of 20 million. But they admit they were perplexed over how the building could have toppled over almost intact.

“When we arrived on the scene, we were very shook up. In my 46 years of work, I’ve never seen or heard of such a thing,” said Jiang Huancheng, a prominent local engineer and professor at Shanghai’s Tongji University.

The accident was an embarrassment for Shanghai, a showcase city of 20 million in the midst of a construction boom as it prepares to host the 2010 World Expo.

Jiang and other officials told reporters their study showed the suburban building’s design and construction conformed with safety regulations and that more analysis is needed to pinpoint the reason why it fell over almost intact.

There are differing opinions among the experts, but the main conclusion is that the cause is a tall pile of dirt next to the building, they said.

“It’s clear that if there had been no pile of dirt, there would have been no problem,” said Fan Qingguo, an engineer with state-run Shanghai Construction Group.

Other experts explained that dirt excavated for the garage may have compacted the soil, causing it to shift and damage the building’s foundations so that it fell over. Heavy rains and cracks in a flood wall for a nearby river also suggest problems with the soil on the site, they said.

Unusually aggressive reports by the state-controlled media have centred on possible collusion between the property developer, the contractor and others supervising the work. Earlier this week, the government said nine people were “under supervision” in connection with the investigation.

Officials in Shanghai’s Minhang district, the location of the “Lotus Riverside” apartment compound where the building fell, will release results of their investigation into responsibility for the disaster later, said city government spokesman Chen Qiwei.

“We absolutely must give society and the people a clear answer,” said Xie Liming, head of Shanghai’s Work Safety Administration.

DCN News Services

Bridges built from recycled plastic

Published: July 2, 2009 at 5:00 PM
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FORT BRAGG, N.C., July 2 (UPI) -- A New Jersey company has developed a system to make bridges from recycled materials that are strong enough to support a U.S. Army tank.

Axion International Holdings, of Basking Ridge, N.J., said the engineers constructed a pair of bridges made entirely from recycled plastic products at Fort Bragg, N.C., and had M1 Abrams tanks driven across the spans.

The M1 Abrams, manufactured by General Dynamics (NYSE:GD), weighs nearly 70 tons, making it too heavy for the vehicle to use most standard bridges and roads.

Axion, in a release, said its composite technology withstood several tank crossings during the tests June 11 at Fort Bragg.

An article on the U.S. Army Corps of Engineers Web site said its Construction Engineering Research Laboratory was involved in the design and building of the test structures. Other U.S. Department of Defense officials were on hand for the testing.

"The first crossing was greeted with a big sigh of relief from some of us and a hardy round of applause from about 30 people in attendance," Richard Lampo, a CERL materials engineer and leader of the project, said in the article.

The company said its new bridges are made entirely from recycled consumer and industrial plastics. The two test thermoplastic spans were made from more than 170,000 pounds -- said to be the equivalent of more than 1.1 million 1-gallon milk jugs -- of recycled plastic. The structures are less expensive to build than traditional wood timber bridges often used on U.S. military bases.

"This represents a truly historic event for both structural engineers and environmentally conscious individuals across the nation," Axion Chief Executive Officer James Kerstein said in a company release.

"Not only are these bridges able to support the weight of a M1 Abrams tank, they are less expensive to build than wooden, concrete or steel bridges and are designed using higher-quality 100 percent recycled structural solutions in a manner that is nearly maintenance-free and eco-friendly."

Axion said its bridges incorporated the company's patented structural materials made from recycled plastic and a patent-pending I-beam design. It also claimed speed of installation and reduced costs for construction and maintenance as benefits.

The tests indicated the structures held up well under both moving and static weight loads and withstood stresses caused when the M1 operator applied the vehicle brakes while on the bridge.

Darryl Butler, a civil engineer with Fort Bragg's Directorate of Public Works, said: "We expect the advantages of the plastic lumber bridge will be lower maintenance costs and the ability to meet long-term training needs. The potential for this innovative material is only limited by the commander's requirements and the mission."

Axion said it developed its patented process in conjunction with researchers at Rutgers University. It says the resulting products are "ideal replacements" for construction materials such as wood, steel or concrete.


© 2009 United Press International, Inc. All Rights Reserved.

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