Project Management in Construction, 5th Edition

For more than thirty years, Construction Project Management by Clough and Sears has been considered the preeminent guide to the Critical Path Method (CPM) of project scheduling. It combines a solid foundation in the principles and fundamentals of CPM with particular emphasis on project planning, demonstrated through an example project.

This Fifth Edition features a range of improvements. New pedagogical devices improve absorption of the material. Updated labor, material, and equipment pricing is incorporated into the text. Coverage is enhanced by discussions of contemporary planning and management methods such as Work Breakdown Structures (WBS) and the Earned Value Management System (EVMS).

A highway bridge with a complete cost estimate, including SI units, illustrates each of the principles of project management. Using this basic information and the case studies in the appendix, readers are given project management problems and hands-on project management experience.

The Fifth Edition features include:

• Complete coverage of planning and scheduling principles that apply to every type of construction project
  Expanded coverage of production planning. Large foldout illustrations conveniently integrated throughout the book
• Thorough and up to date, Construction Project Management, Fifth Edition is a superb text for students and an indispensable on-the-job reference for builders, architects, civil engineers, and other construction professionals.

Title : Construction Project Management

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408 pages, hardcover Wiley (April 25, 2008) - Author: Richard H. Clough , Glenn A. Sears , S. Keoki Sears
- Publisher: John Wiley & Sons
- Categories: Project Management, Scheduling
- Price: $115.00

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• July 31, 2009 -- What is a Suspension Bridge?
• July 24, 2009 -- Bearing
• July 23, 2009 -- History & Introduction
• July 23, 2009 -- Water/ Cemetitous Materials Ratio
• August 9, 2009 -- Supervision of Concrete Construction
• July 25, 2009 -- The Art of Project Scheduling
• July 23, 2009 -- Structural Numbers
• July 23, 2009 -- Water Pressure
• August 17, 2009 -- National Standard Plumbing Code 2003

Oldcastle Materials Inc. considers rebuilding larger wheel loaders when they reach the end of their first life.

Extreme maintenance practices can help you extend equipment life spans — but be aware you are managing risk.

In today’s economy, we’re all trying to stretch things as far possible. Whether it’s stretching time between oil changes in your car or holding off on buying that new pair of work boots you know you need, we’re pushing the limits.

The construction industry is no exception. Its economic downturn has prompted many contractors to run equipment for more hours than normal. Capital for new machines is scarce so equipment is being kept longer and worked harder. Knowing that the equipment has to last, managers carefully watch oil samples for wear particle signals that mean component failure is approaching. And some equipment managers are even replacing small components, such as water pumps and alternators, before they fail.

“We’re probably adding 20 percent more to the life of our equipment than we would in normal economic times,” says Rex Davis, a vice president at RMCI Inc., Albuquerque, N.M. “Sooner or later we have to make some decisions (about trading in equipment). It doesn’t do any good to have new equipment if you don’t have work for it. Hopefully the economic tide will turn soon.”

Davis replaces small components such as turbochargers and water pumps before failure. “A turbocharger normally runs 5,000 to 7,000 hours, and once you get past that you start looking at it,” Davis says. “We do go by historical failure records on small components. A contractor’s history is a better representation of what the equipment will do than someone else’s suggested failure times.”

Equipment managers need to make a plan for running equipment longer than usual. You watch wear indicators such as oil sample analysis. Outside companies will do vibration analyses that can pinpoint problems or incipient failures. “The plan will call for additional observations of known maintenance items — and some tests for wear indicators you normally would not suspect,” Davis says.

Finding the ‘sweet spot’

Dan Connelly, vice president of equipment services for Oldcastle Materials Inc. in Atlanta, notes that demand for his company’s construction services is down, so equipment is being kept longer. However, he points out, the equipment is not working its usual number of hours. “Operating hours, not calendar days, is the important factor in determining our replacement cycles,” Connelly says. With about 40,000 pieces of rolling stock and eight divisions, Oldcastle is one of the nation’s largest construction contractors.

Connelly says Oldcastle strives to replace most equipment at the “sweet spot” — the optimum point in a machine’s financial life just before its repair costs balloon and major components need replacements. Oldcastle determines its own sweet spot for each category of equipment, based upon historical records and analysis of owning and operating costs.

However, in some categories of equipment, such as 7-cubic-yard wheel loaders, Oldcastle considers going for a second life by replacing major components. Forty-ton and larger rigid-frame haul trucks would also be considered for major component replacements. The company owns about 500 dozers and 800 excavators, but “typically we don’t rebuild them,” Connelly says.

How about replacing small components before failure? Yes, says Connelly. “We certainly attempt to replace components such as starters, alternators, and water pumps before failure,” he says. “We advocate condition-based maintenance.”

The level of service that Oldcastle procures from equipment dealers depends on the relationship of each division with its local equipment dealers, Connelly says. Each division has multiple shops that do preventive maintenance and some repairs.

Oldcastle uses Viewpoint management software, which has an equipment module. That module identifies each piece of equipment by a unique number. Revenues, as well as operating hours and all costs, including oil changes, parts and repairs, are tracked for each piece of equipment. “We take data that is housed in Viewpoint to determine the optimum equipment life cycles,” Connelly says. “We look at each piece of equipment multiple times each year.”

With 40,000 plus pieces of equipment, Oldcastle Materials is one of the nation’s largest contractors. But it, too, is keeping equipment longer than usual.
The Washington Division of URS Corp. keeps equipment based on site-specific applications, says Bob Merritt, director of maintenance at the Boise, Idaho-based firm. The Washington Division owns 2,000 plus pieces of equipment that work at construction sites, quarries and mines around the world.

“We keep equipment on long-term projects based on application and production,” Merritt says. “Whereas most contractors try to get rid of machines before the first major rebuild, we may hold it longer and go through one or two rebuilds on many pieces. The number of hours is driven by the class of equipment.”

Take 50- to 70-ton excavators, for example. Washington has some that range from 14,000 hours up to around 25,000 hours on longer-term projects. Front shovels and mining excavators run longer — up to 60,000 hours.

How about dozers? “Typically we try to get rid of the less-than-300 horsepower class at about 10,000 to 12,000 hours; the 300- to 500-hp class in 20,000 hours and the above-500-hp class in 50,000 hours,” Merritt says. “Even at those hours, that’s longer than most people run them.”

With 40,000 plus pieces of equipment, Oldcastle Materials is one of the nation’s largest contractors. But it, too, is keeping equipment longer than usual.

Washington Division will do a major rebuild at 12,000 to 14,000 hours on a construction dozer. That means the complete power train gets rebuilt components — engine, transmission, torque converter and final drives.

Why keep equipment longer? “If it adds value we do it,” Merritt says. “In the last few years, until the downturn, it’s been difficult to get the equipment we needed. The low availability of new and used equipment made the price go up. Now with the change of the economy, lots of equipment in the smaller to medium-sized classes is currently available.”

Scarce capital

Capital for new equipment is very limited and profit margins are tighter than ever at American Infrastructure, says Mike Monnot, vice president of equipment for the Worcester, Pa.,-based construction company. The firm owns about 700 pieces of rolling stock and 350 on-road trucks. “So unfortunately, yes, we’re keeping equipment longer than we would like to,” Monnot says.

To run typical construction equipment beyond 10,000 hours is to gamble that you won’t have a catastrophic component failure, Monnot says. If you do get the major component failure, you have to repair it, because you can’t sell it in a failed condition. Then the other components still have the potential for failure. And the equipment’s technology becomes obsolete.

“So if a company makes a decision to keep the equipment longer, the only option that you really have is to do planned, predictive maintenance and schedule components to be changed out at intervals,” Monnot says.

“Through scheduled maintenance we’ve gotten as many as four life cycles, or 24,000-plus hours, out of large wheel loaders,” Monnot says. The wheel loaders work for a subsidiary called Independent Construction Materials, which runs asphalt plants. Monnot recommends getting expected component lives from the manufacturers, then watching all indicators of wear — oil samples, vibration analysis, wear measurements and the like. “You come as close to that end of life as you can,” he says.

In better economic times, Monnot likes to keep a newer fleet. “Typically I prefer to cycle equipment out at the end of its first life in construction, and in mining, maybe the second life,” Monnot says. “Beyond that, I would rotate it out and exchange it for new machines.”

Oldcastle Materials uses the equipment module in Viewpoint software to help manage the maintenance schedules on its equipment.

Oldcastle Materials uses the equipment module in Viewpoint software to help manage the maintenance schedules on its equipment.

K-Five Construction Corp. is not keeping equipment any longer than usual because of the economic downturn, says Dave Gorski, shop administrator for the Lemont, Ill.-based paving contractor. He says last year wasn’t a bad year, but there doesn’t look to be much work for the current year.

“We have a 20 to 25-year replacement plan that calls for replacing everything sooner or later, and it’s tied to an annual capital budget,” Gorski says. “We own more than 600 pieces of on- and off-road equipment. Our replacement plan is done by years, so our replacements are pretty predictable and we aim to keep our capital spending on an even keel. But we do tweak the plan here and there based on factors like the volume of work we have or what the EPA is doing to us in terms of emission requirements.”

Fuel-based PM

Dale Warner, fleet director for Fort Myer Construction in Washington, D.C., has been using fuel-based preventive maintenance intervals since 1980. Recently hired at Fort Myer to reduce equipment owning and operating costs, Warner is implementing severity-based intervals — based on fuel usage — for the firm’s 600-plus machine fleet.

“Fuel use is the only way I know to judge the severity of an application, to tell how hard the machine is working,” Warner says. Previously, Warner used severity-based intervals at C.J. Miller LLC, a general contractor in Hampstead, Md., and at C.J. Langenfelder & Son Inc., formerly of Baltimore and now defunct.

At Fort Myer, Warner will start by changing engine oil at a fuel usage interval equal to 75 gallons times the number of quarts of oil in the crankcase. So if an engine holds 40 quarts of oil, multiply that by 75 and you get 3,000 gallons of fuel. When the engine has burned 3,000 gallons of fuel, it’s time to change oil.

“The hourly intervals will vary widely,” Warner says. “When I was at Miller, we averaged about 560 hours per oil change. Some we changed in 300 hours, some were 700 or higher. We did one at 800 hours.”

Oil analysis is a necessary part of extended oil change intervals, Warner says, warning that you have to watch wear metal particle counts versus their limits.

If you want to use fuel-based intervals, Warner recommends starting at 70 gallons times the quarts of crankcase oil. Watch the oil samples, then inch it up to 75 gallons, then 80 gallons, and 90 next. “A major manufacturer said 70, but I’ve been successful at using 90 gallons as the multiplier as new technology has developed,” he says.

Warner’s results are impressive. One year Miller did a total of 1,445 oil changes. The next year, by using fuel-based intervals, oil changes dropped by 40 percent. The savings in dollars: more than $400,000, figuring $760 per oil change. v

Author’s note: All of the equipment managers quoted in this story belong to the Association of Equipment Management Professionals. For more information about AEMP, go to www.aemp.org.

Measure, manage, monitor to maximize

Dale Warner plans to install a completely automated fuel reporting system at Fort Myer using a Fuelmaster reporting system at its pump island and its fuel trucks.

Both will have an electronic chip in the dispensing nozzle. When fueling takes place, the nozzle will receive equipment information — unit number, equipment hours and miles — through a transmitter in a ring installed at the fuel tank neck. When the fuel truck gets within 900 feet of a central data receiver, all fuel/equipment information will automatically transmit and upload into the contractor’s equipment management system.

With the help of on-board electronics, the Fuelmaster system will report time spent idling, miles, hours, fault codes, type of fuel used and time and date of fueling. Warner hopes to help reduce idling time dramatically. “If our fleet averages a half-hour of idle time for a year, that’s $300,000,” he says. “If we can cut that idle time to 15 minutes per day, that’s a savings of $150,000.

The system identifies who is idling, Warner points out, and the information is then given to senior management so appropriate action may be taken.

From betterroads.com

• August 21, 2009 -- Highway Capacity Software

Structural details in concrete

Here the reader is given examples of some reinforced, composite and prestressed concrete bridges with simplified structural details. A number of books have been published on various aspects of concrete design and detailing, but this is believed to be the first comprehensive detailing manual, and covers details in reinforced, prestressed, precast and composite concrete.

Ebook Details :

• Paperback: 234 pages
• Publisher: Mcgraw-Hill (January 1988)
• Language: English
• ISBN-10: 0070463603
• ISBN-13: 978-0070463608
• Product Dimensions: 11.2 x 9 x 0.8 inches

Title : Structural details in concrete

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Structural details in concrete

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• September 27, 2009 -- Design of Highway Bridges: An LRFD Approach
• August 16, 2009 -- Introduction to Health and Safety in Construction
• July 24, 2009 -- What is a Contractor?
• July 24, 2009 -- Steps to Successful Schedules in Project Management
• July 28, 2009 -- Golden Gate Bridge
• August 18, 2009 -- Building Science for Architects
• October 17, 2009 -- Intelligent Structural Elements
• August 3, 2009 -- Stressed ribbon bridge
• July 23, 2009 -- Job Guide to Civil Engineers

Estimating and Tendering for Construction Work

Estimators need to understand the consequences of entering into a contract, often defined by complex conditions and documents, as well as to appreciate the technical requirements of the project. Estimating and Tendering for Construction Work explains the job of the estimator through every key stage, from early cost studies to the creation of budgets for successful tenders.

 This new edition reflects recent developments in the field such as new tendering and procurement methods; the move from basic estimating to cost-planning and the greater emphasis placed on partnering and collaborative working. It also includes changes to pricing, rates, terminology and technology to bring the book completely up-to date. Clearly-written and illustrated with examples, notes and technical documentation the book is ideal for students on construction-related courses needing to understand these essential processes or professionals beginning in industry.

Audience
Students learning estimating and tendering as part of building surveying, construction management, quantity surveying and civil engineering courses. May be of interest to professional estimators beginning in industry.

Contents
Preface; Acknowledgements; List of figures; Abbreviations used in the text; Organisation of the estimating function; Procurement paths; Forms of contract; Tender documentation; Estimating methods; Contractor selection and decision to tender; Project appreciation; Enquiries to suppliers and sub-contractors; Tender planning and method statements; Resource costs – labour, materials and plant; Unit rate pricing; Sub-contractors and nominated suppliers; Fluctuations; Provisional sums and dayworks; Project overheads; Cashflow forecasts; Completing the estimate and final tender review; Tender submission and results; Action with the successful tender; Computer-aided estimating; Further reading; Index

Title : Estimating and Tendering for Construction Work

Version : Fourth Edition | Post date : 2010-01-08

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Estimating and Tendering for Construction Work

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• August 16, 2009 -- Asphalt Surfacings
• July 24, 2009 -- Recommendations
• August 9, 2009 -- Concrete Construction Engineering Handbook
• July 23, 2009 -- History & Introduction
• July 23, 2009 -- Lateral Pressrues In Cohesive Soils
• August 17, 2009 -- Building Code of Pakistan (Seismic Provisions-2007)
• July 25, 2009 -- Time Estimates and Planning in Project Management
• July 23, 2009 -- Water Pressure
• July 24, 2009 -- Plate Girder In Buildings

Twinkle Kisogawa bridge

An extradosed bridge employs a structure that is frequently described as a cross between a girder bridge and a cable-stayed bridge. The name comes from the French word extradossé, which is derived from the word extrados. Extrados is defined as the exterior curve of an arch.

This description is somewhat deceptive, since many cable-stayed bridges have some sort of box-girder deck. The difference is one of degrees.

A typical cable-stay bridge has a tower with a height above the deck at least half the span to the next support, since the cables are the vertical support and must come at a relatively high angle.

In an extradosed bridge, the deck is directly supported by resting on part of the tower, so that in close proximity to the tower the deck can act as a continuous beam. The cables from a lower tower intersect with the deck only further out, and at a lower angle, so that their tension acts more to compress the bridge deck horizontally than to support it vertically. Thus the cable stays act as prestressing cables for a concrete deck, whether made with I-beam girders or a box girder. The deck of an extradosed bridge can be thinner than that of a comparable span-beam bridge, but must be thicker than that of a conventional cable-stayed bridge of comparable span.
Given its intermediate design, it is unsurprising that extradosed bridges are relatively expensive and material inefficient. Almost any span that could be bridged by an extradosed bridge could be spanned more inexpensively with a continuous girder, or more efficiently (but at even greater cost) with a cable-stayed. In most cases the spans are short enough that the use of cables at all is an aesthetic rather than engineering-necessitated choice. This does not imply that is a “bad” choice, since in some cases the difference in cost and efficiency is small, and the extradosed type is a very elegant form.

It is debatable whether an “extradosed” type even exists; several notable designs amount to extradosed bridges, but have never been described as other than “cable-stayed”. For example, Christian Menn built two notable bridges in Switzerland that fit the extradosed description: Ganter Bridge and Sunniberg Bridge. They are consistently described as “hollow box cable-stayed” or “low-tower cable-stayed”. Only two bridges in the United States uses the extradosed moniker; the Pearl Harbor Memorial Bridge in Connecticut and the Gibbs Street Pedestrian Bridge in Oregon, both of which are currently under construction. The term appears to be more popular in East Asia and Latin America. It is still a very rare form, with Structurae listing only 36 entries, with more than half either in planning or construction rather than completed and in use.

Extradosed bridge in Latvia

The Southern Bridge over the Daugava River in Riga, Latvia is presently the biggest construction project in Latvia and its capital city, Riga. In terms of work volume it can only be compared to the Island Bridge that was built in the seventies. Work on the development of the Southern Bridge project started in 2002, when the City Development Department of the Riga City Council developed the design task for the route of the Southern Bridge, which would connect Vienības Anenue on the left bank of the Daugava River and the Slāvu Roundabout on the right bank of the Daugava River. The Southern Bridge over represents a multispan structure of 49.5 + 77 + 5 × 110 + 77 + 49.5 metres known as extradosed system with 6 traffic lanes. The total length of the bridge – 803 metres. The width of the bridge – 34.28 metres. The number of pylons – six, each at a height 13.33 metres above the roadway pavement. Each pylon has 8 pairs of cables.

India’s first extradosed bridge

India’s first extradosed bridge has been built by Gammon India Ltd. and the Delhi Metro Rail Corporation for the New Delhi Mass Rapid Transit System between Pragati Maidan and Indraprastha over Indian Railways tracks. This bridge is 196.3 metres long, with the main span over the railway lines 93 metres long. In addition, the bridge has a 302-metre radius curvature and the main span has been kept long to allow for future expansion of Indian Railways lines. This bridge is being designed and managed by French consultant, Systra. Prior to this the first such bridge was constructed in Japan.

Extradosed bridges in Canada

The North Arm Bridge, used by the Canada Line connecting Vancouver with its suburb of Richmond over the Fraser River has been billed as North America’s first extradosed bridge. The Canada Line went into service on August 17, 2009.

The Golden Ears Bridge, also crossing the Fraser but between the municipalities of Pitt Meadows / Maple Ridge and Langley, is the longest extradosed bridge in North America. The bridge opened to traffic on June 16, 2009.

From wikipedia.org

• August 3, 2009 -- Stressed ribbon bridge
• July 23, 2009 -- Types of bridges
• August 9, 2009 -- Prestressed Concrete Bridges: Design and Construction
• August 15, 2009 -- Energy and Environment in Architecture
• August 13, 2009 -- Steel Structures: Design and Behavior (4th Edition)
• August 16, 2009 -- A Source Book for Architects and Structural Engineers
• July 25, 2009 -- The Art of Project Scheduling
• August 18, 2009 -- Theory of Bridge Aerodynamics
• July 24, 2009 -- Shotcrete

For Roger Friede, saving more than $12,000 per employee in workers’ compensation premium costs over the past ten years only partially explains his strong commitment to safety.

How Your Construction Company Can Make Safety Pay

Friede, president of Friede & Associates, LLC, a thirty-employee commercial construction firm in Reedsburg, WI, says what drives him the most in emphasizing safety is that “I don’t ever want to have to explain to somebody why that person’s father or husband isn’t coming home that night.”

On May 15, 2009, Friede’s company, which has never had a job-related fatality, celebrated six and a half years with no lost-time incidents. In an industry where serious hazards are an everyday part of the job, Friede & Associates’ example shows that making safety part of your company’s corporate culture can significantly reduce costs and save lives.

“Most people look at small businesses and see safety as being challenging because of resource issues. This is understandable. They are resource limited,” said Mei-Li Lin, executive director of research and statistical services at the National Safety Council. “However, small businesses are a lot more sensitive to safety and health outcomes. If there is an injury, they do not have the luxury of having somebody to replace the injured person. Also, every loss has a huge impact on small businesses.”

Friede & Associates, which has an experience modification rate (EMR)* that fluctuates between .71 and .85, estimates that it has spent approximately $3,825 per employee for its safety program over the past ten years. Even with those expenditures, the company has realized a net savings of $8,233 or more per employee during that period (the $8,233 assumes an EMR of .85) due to its low EMR and corresponding workers’ compensation premium rate.

Tip of the Iceberg

Friede & Associates, a company with roots dating back to the late 1890s, has focused on commercial construction the past sixty-four years. But it wasn’t until 1987 when Roger Friede became president, that the firm began proactively looking at safety from the top on down. “Just before that, one of our workers fell through the roof at a commercial construction site. He was seriously injured and later came back to work, but this was a wake-up call for us,” Friede said.

Over the years, the company learned what many construction companies learn: That even a minor injury results in much more than the direct medical costs covered by workers’ compensation.

“The direct, insured costs are just the tip of the iceberg,” said Ginny Frings, Ph.D., coordinator of the Center for Entrepreneurship and Innovation at Xavier University in Cincinnati, OH. Hidden, out-of-pocket costs borne by the employer typically also include such items as time lost from work by the injured employee, co-workers and the injured person’s supervisor; reduced production; recruitment and training costs for new replacement workers; damage to tools and equipment; overhead costs while work was disrupted and the failure to meet customer deadlines. These and other hidden costs often range from four to five times the direct costs of an injury/incident.

In Friede & Associates’ case, the company decided not to wait for another serious injury to occur. Instead, it began building what is now a very strong safety program. Its many key elements include such items as pre-job safety planning, company safety goals, safety training for employees, superintendent safety performance audits and a once a year external program review.

The first step the company took was to see what resources were already available. It joined an area council comprised of representatives from both construction and general industry. It also became involved in an industry trade association which provides members with “toolbox” safety talks, sponsors safety training classes, assists in evaluating the company’s safety efforts on an annual basis, and serves as a resource for questions about the Occupational Safety and Health Administration (OSHA) regulations.

Another key step Friede & Associates took early on was to put its safety program into writing. This written program, which has undergone many revisions, additions and regular reviews, includes the safety responsibilities of everyone in the company, said Terry Greenwood, Friede’s general superintendent and safety director.

“One of the first pages of our written plan lists the responsibilities of the president of the company, our safety committee and our field force,” Greenwood said. Among his safety responsibilities are to document the types of training each employee has completed (such as fall protection or confined spaces training), then let the person know if refresher training is needed; regularly monitor jobsites for the use of required personal protective equipment (PPE); accompany employees to external safety meetings and safety presentations and work closely with all jobsite superintendents.

The latter includes planning in advance of starting a job to identify potential hazards and whether specialized equipment will be needed, then ensuring it is at the jobsite when work begins. This helps prevent delays and reduces the risk that crew members will take shortcuts. “You are going to take shortcuts when you don’t plan properly,” Greenwood said-shortcuts which could result in serious injury.

One result of all of Friede & Associates’ safety efforts over the years is that crew members look out for each other in the field, both Friede and Greenwood say. They see top management “walking the talk,” which includes many small efforts that don’t cost much money, such as bringing doughnuts to a jobsite with a note on the box that says: “Thanks for being safe.”

“It’s continuing reinforcement,” Friede explained. “Once you start getting past that one year mark, your employees are looking out for each other. Once your safety program is out there a couple of years, no one wants to be the one to undo it.”

Steps to Take For Safety Success

• Ensure that top management is truly committed to safety. It is critical that top management be involved in safety and that a program be developed that assigns responsibilities, provides access to safety training and supports your company’s safety goals. Safety can be approached from a return-on-investment (ROI) perspective. Frings suggests that you review injuries and other incidents (such as property damage incidents) in terms of numbers of insurance claims, length and size of claims, reduced productivity, lost personnel time and similar factors. Next, determine how much you will invest in your safety program and forecast the savings/benefits. If you have never done this, ask your insurance agent or workers’ compensation insurance company for assistance. Note: ROI approaches are more difficult to measure for health hazards such as hearing loss and silicosis.
• Involve your employees. “Engaging employees at all levels in the design, promotion and adoption of your program will result in greater ‘buy-in’ to the process,” Frings said. It is important for company management to “have employees identify opportunities themselves. Then everybody becomes the ‘eyes and ears’ for continuous improvement,” Lin added. Among the specific ways you can do this are to develop a safety committee that includes representation from all levels of your work force, encourage crew members to assess jobsites for hazards on a daily basis and brainstorm on ideas for improvement, and have employees lead toolbox safety talks.
• Be familiar with all of the OSHA regulations that affect your operation. To link to federal OSHA’s construction standards, visit www.osha.gov, then click on “Regulations” at the top of the home page, then on “Part 1926 Safety and Health Regulations for Construction.” Note: It’s important to know whether any of the states in which you do business fall under a State OSHA Plan. State OSHA Plans’ standards must be at least as strict as federal OSHA standards but are often stricter. Visit www.osha.gov/dcsp/osp/index.html for more information.
• Identify the other free resources available to assist you. In addition to your insurer, trade organizations and local safety organizations, don’t be afraid to talk to the general contractor down the road about what his or her company is doing to promote safety, Friede suggests. Many other free resources are also available. These include:

1. OSHA resources. The OSHA On-Site Consultation Program, www.osha.gov/dcsp/smallbusiness/consult.html. This program offers confidential advice to small and medium-sized companies with priority given to high hazard work sites. OSHA’s Small Business Web page, www.osha.gov/dcsp/smallbusiness. OSHA’s Safety and Health Topics Web page, www.osha.gov/SLTC/index.html. Then search for “Construction Industry,” where you can find additional OSHA resources such as construction eTools. OSHA’s $afety Pays Program, www.osha.gov/dcsp/smallbusiness/safetypays/index.html, is an interactive system that assists employers in estimating the costs of occupational injuries and illnesses and the impact on a company’s profitability.
2. National Institute for Occupational Safety and Health (NIOSH) resources. The NIOSH Safety and Health Topic: Small Business Web page, www.cdc.gov/niosh/topics/smbus, where you can link to numerous resources aimed at assisting small businesses, including the “Safety and Health Resource Guide for Small Businesses.” The NIOSH Safety and Health Topic: Construction Web page, www.cdc.gov/niosh/topics/construction, where you can link to many documents (some in both English and Spanish) on such specific hazards as falls, electrocution, silica dust/silicosis and ergonomic injuries.
3. Center for Construction Research and Training. Electronic Library of Construction Occupational Safety and Health, www.elcosh.org. Hazard Alerts (on a number of topics in both English and Spanish), www.cpwr.com/rp-hazardalerts.html.
4. WorkSafeBC Safety at Work Construction Information. www2.worksafebc.com/Portals/Construction/Home.asp (for toolbox safety meeting guides and other materials).

An EMR of 1.0 means a company has an average safety record compared to other companies with similar characteristics in the industry. Anything above that means a company’s injury/incident rate is above the norm for its industry. The EMR is one factor used by all insurance companies to calculate the cost of an employer’s workers’ compensation premium.

Barbara Mulhern is president of RB Editorial & Consulting, Inc., a Verona, WI-based editorial and safety consulting firm. She has specialized in occupational safety and health writing the past fifteen years and has produced more than 150 short safety training lessons that have been used to train English- and Spanish-speaking workers nationwide. Questions about this article can be addressed to Mulhern at 608.848.3758.

From Construction Business Owner, December 2009

• August 16, 2009 -- Introduction to Health and Safety in Construction

Why Did Cowboys Facility Collapse?

A fabric-covered, steel frame practice facility owned by the National Football League’s Dallas Cowboys collapsed under wind loads significantly less than those required under applicable design standards, according to a report released on October 6 for public comment by the Commerce Department’s National Institute of Standards and Technology (NIST).

Located in Irving, Texas, the facility collapsed on May 2, 2009, during a severe thunderstorm. Twelve people were injured, one seriously.

Based on the national standards for determining loads and for designing structural steel buildings, NIST researchers studying the Cowboys facility found that the May 2 wind load demands on the building’s framework—a series of identical, rib-like steel frames supporting a tensioned fabric covering—were greater than the capacity of the frame to resist those loads.

Assumptions and approaches used in the design of the Cowboys facility led to the differences between the values originally calculated for the wind load demand and structural frame capacity compared to those derived by the NIST researchers. For instance, the NIST researchers included internal wind pressure due to the presence of vents and multiple doors in their wind load calculations because they classified the building as “partially enclosed” rather than “fully enclosed” as stated in the design documents. The NIST researchers also determined that the building’s fabric could not be relied upon to provide lateral bracing (additional perpendicular support) to the frames in contrast to what was stated in the design documents and that the expected wind resistance of the structure did not account for bending effects in some members of the frame.

“Our investigation found that the facility collapsed under a wind load that a building of this type would be expected to withstand,” said study leader John Gross. “As a result of our findings, NIST is recommending that fabric-covered steel frame structures be evaluated to ensure the adequate performance of the structural framing system under design wind loads.”

The NIST report recommends that such evaluations determine whether or not: (1) the fabric covering provides lateral bracing for structural frames considering its potential for tearing; (2) the building should be considered partially enclosed or fully enclosed based on the openings that may be present around the building’s perimeter; and (3) the failure of one or a few frame members may propagate, leading to a partial or total collapse of the structure.

Shortly after the Cowboys facility’s collapse, NIST sent a reconnaissance team of three structural engineers to assess the failed structure and wind damage in the surrounding area, and collect relevant data such as plans, specifications and design calculations. Using the data acquired during the reconnaissance, the NIST study team developed a computer model of a typical structural frame used in the practice facility and then studied the frame’s ability to resist forces under two wind conditions: the wind loads based on the design standard wind speed of 90 miles per hour and the actual wind loads based on conditions at the time of the collapse.

NIST worked with the National Oceanic and Atmospheric Administration’s (NOAA) National Severe Storms Laboratory to estimate the wind conditions at the time of collapse. The researchers determined that, at the time of collapse, the wind was blowing predominantly from west to east, perpendicular to the long side of the building. Maximum wind speed gusts at the time of collapse were estimated to be in the range of 55 to 65 miles per hour—well below the design wind speed of 90 miles per hour in the national standard for wind loads. The center of a microburst (a small, intense downdraft which results in a localized area of strong winds) associated with the May 2 thunderstorm was located about one mile southwest of the structure at the time of collapse.

According to the NIST and NOAA researchers, the wind field in the vicinity of the Cowboys facility at the time of collapse was consistent with design standards and not unusual.

Based on their study of the wind conditions at the time of collapse and the structural response, the NIST researchers determined the following likely collapse sequence:

• Buckling of the inner chord (inner side of the roof truss) of a frame in a section of the roof on the east side resulted in the formation of a kink in the frame.
• Failures of the east and west “knees” (connections between the side walls and the roof) allowed the frame to sway eastward with the wind.
• Compressive failure of the east side at the roof’s highest point (ridge) led to fractures of the nearby inner and outer chords in the vicinity of the ridge.
• A progression of frame failures throughout the structure resulted in total structural collapse.

The draft report is available online at http://www.bfrl.nist.gov/investigations/investigations.htm.

From  ScienceDaily .

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