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Photo courtesy of Thinkstock. Structural Steel Design EDUCATION MODULE. Developed by T. Michael Toole, Ph.D., PE Daniel Treppel Stephen Van Nosdall Bucknell University. Structural Steel. Guide for Instructors. Learning Objectives.
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Photo courtesy ofThinkstock Structural SteelDesign EDUCATIONMODULE Developed by T. Michael Toole, Ph.D.,PE DanielTreppel StephenVanNosdall BucknellUniversity StructuralSteel
Guide forInstructors StructuralSteel
LearningObjectives • Explain the Prevention through Design (PtD)concept. • List reasons why project owners may wish to incorporate PtD in their projects. • Identify workplace hazards and risks associated with design decisions and recommend design alternatives to alleviate or lessen thoserisks. StructuralSteel
Overview • PtDConcept • Steel Design, Detailing, and FabricationProcess • Steel ErectionProcess • Specific Steel PtD Examples Photo courtesy ofThinkstock StructuralSteel
Introduction to Prevention throughDesign EDUCATIONMODULE StructuralSteel StructuralSteel
Occupational Safety andHealth • Occupational Safety and Health Administration (OSHA) www.osha.gov • Part of the Department ofLabor • Assures safe and healthfulworkplaces • Sets and enforces standards • Provides training, outreach, education, andassistance • State regulations possibly morestringent • National Institute for Occupational Safety and Health (NIOSH)www.cdc.gov/niosh • Part of the Department of Health and Human Services, Centers for Disease Control andPrevention • Conducts research and makes recommendations for the prevention of work-related injury andillness StructuralSteel
ConstructionHazards • Cuts • Electrocution • Falls • Falling objects • Heat/coldstress • Musculoskeletaldisease • Tripping • [BLS 2006; Lipscomb et al.2006] Graphic courtesy ofOSHA StructuralSteel
Construction Accidents in the UnitedStates • Construction is one of the most hazardous occupations. This industry accountsfor • 8% of the U.S. workforce, but 20% offatalities • About 1,100 deathsannually • About 170,000serious injuriesannually • [CPWR2008] Photo courtesy ofThinkstock StructuralSteel
Design as a Risk Factor: Australian Study,2000–2002 • Main finding: design contributes significantly to work-related serious injury. • 37% of workplace fatalities are due to design-relatedissues. • In another 14% of fatalities, design-related issues may have played a role. • [Driscoll et al.2008] Photo courtesy ofThinkstock StructuralSteel
Accidents Linked toDesign • 22%of226injuriesthatoccurredfrom2000to2002inOregon, Washington,andCaliforniawerelinkedpartlytodesign[Behm • 2005] • 42% of 224 fatalities in U.S. between 1990 and 2003 were linked to design [Behm2005] • In Europe, a 1991 study concluded that 60% of fatal accidents resulted in part from decisions made before site work began [European Foundation for the Improvement of Living and Working Conditions,1991] • 63% of all fatalities and injuries could be attributed to design decisions or lack of planning [NOHSC 2001] StructuralSteel
Falls • Number one cause of constructionfatalities • – in 2010, 35% of 751deaths • www.bls.gov/news.release/cfoi.t02.htm • Common situations include making connections, walking on beams or near openings such as floors or windows • Fallprotectionisrequiredatheightof6feetabove a surface[29 CFR 1926.760]. • Common causes: slippery surfaces, unexpected vibrations, misalignment, and unexpectedloads StructuralSteel
Death fromInjury Number of deaths per 100,000 full-timeworkers Ironworker61.6 Electrical power-lineinstaller Roofer Truckdriver ConstructionLaborer Welder Op.Engineer Helper ExcavatingOperator Foreman Electrician BrickMason Painter Heating Constructionmanager Plumber Carpenter Drywall Allconstruction 58.6 32.1 23.5 21.5 20.3 16.0 15.6 Rate of work-related deaths from injuries, selected construction occupations, 2003–2009average 14.3 11.5 10.4 8.8 8.1 Full-time equivalent (FTE) is defined as 2,000 hours worked peryear. [BLS 2003–2009; CPWR2008] 7.8 7.7 7.2 6.9 4.9 10.8 StructuralSteel
Fatality Assessment and ControlEvaluation NIOSH FACE Programwww.cdc.gov/niosh/face StructuralSteel
What is Prevention throughDesign? • Eliminating or reducing work-related hazards and illnesses and minimizing risks associatedwith • Construction • Manufacturing • Maintenance • Use, reuse, and disposal of facilities, materials, and equipment StructuralSteel
Hierarchy of Controls per ANSI/AIHAZ10-2005 BESTBEST ELIMINATION Design itout SUBSTITUTION Use somethingelse ENGINEERINGCONTROLS Isolation andguarding ADMINISTRATIVECONTROLS Training and workscheduling PERSONAL PROTECTIVEEQUIPMENT Lastresort Control Business value effectiveness StructuralSteel
Personal Protective Equipment(PPE) • Last line of defense againstinjury • Examples: • Hardhats • Steel-toedboots • Safetyglasses • Gloves • Harnesses Photo courtesy ofThinkstock OSHAwww.osha.gov/Publications/osha3151.html StructuralSteel
PtDProcess [Hecker et al.2005] • Establish PtDexpectations • Include construction and operationperspective • Identify PtD process andtools Design External review Internal review Design team meeting Issue for construction • Owner • Architect • ProjectManager • Health & Safety Professional • Tradecontractor • Health & Safety review • QualityAssurance/ QualityControl • Health & Safetyreview • ValueEngineering review • Focused Health& Safetyreview • Ownerreview StructuralSteel
Integrating Occupational Safety and Health with the DesignProcess StructuralSteel
Safety Payoff During Design [Adapted from Szymberski1997] High Conceptualdesign Detaileddesign Procurement Ability to influence safety Construction Start-up Low Projectschedule StructuralSteel
PtD ProcessTasks [Adapted from Toole 2005; Hinze and Wiegand1992] • Perform a hazardanalysis • Incorporate safety into the designdocuments • Make a CAD model for member labeling and erection sequencing Photo courtesy ofThinkstock StructuralSteel
DesignerTools • Checklists for construction safety [Main and Ward1992] • Design for construction safety toolbox [Gambatese et al.1997] • Construction safety tools fromAustralia • – Construction Hazard Assessment Implication Review, known as CHAIR [NOHSC2001] StructuralSteel
ExampleChecklist Checklist courtesy of JohnGambatese StructuralSteel
OSHA Steel Erection eTool OSHAwww.osha.gov/SLTC/etools/steelerection/index.html StructuralSteel
Why Prevention throughDesign? • Ethicalreasons • Constructiondangers • Design-related safety issues • Financial andnon- financialbenefits • Practicalbenefits Photo courtesy ofThinkstock StructuralSteel
Ethical Reasons forPtD • National Society of Professional Engineers’ Code of Ethics: “Engineers shall hold paramount the safety, health,and • welfare of thepublic…” • American Society of Civil Engineers’ Code of Ethics: “Engineers shall recognize that the lives, safety,health • and welfare of the general public are dependent upon engineeringdecisions…” NSPEwww.nspe.org/ethics ASCEwww.asce.org/content.aspx?id=7231 StructuralSteel
PtD Applies toConstructability • How reasonable is thedesign? • Cost • Duration • Quality • Safety Photo courtesy of the Cincinnati Museum Centerwww.cincymuseum.org StructuralSteel
Business Value of PtD • Anticipate worker exposures—beproactive • Align health and safety goals with businessgoals • Modify designs to reduce/eliminate workplace hazardsin Facilities Tools Products Equipment Processes Workflows Improve businessprofitability! AIHAwww.ihvalue.org StructuralSteel
Benefits ofPtD • Reduced site hazards and thus fewerinjuries • Reduced workers’ compensation insurancecosts • Increased productivity • Fewer delays due toaccidents • Increased designer-constructorcollaboration • Reducedabsenteeism • Improvedmorale • Reduced employeeturnover StructuralSteel
Industries Use PtDSuccessfully • Constructioncompanies • Computer and communicationscorporations • Design-buildcontractors • Electrical powerproviders • Engineering consultingfirms • Oil and gasindustries • Water utilities And manyothers StructuralSteel
STRUCTURAL STEELDESIGN Design, Detailing, and Fabrication Process StructuralSteel
Three Entities Associated withDesign • Engineer • Detailer • Fabricator Photo courtesy ofThinkstock StructuralSteel
DesignPhase • Owner establishes architectural/engineering requirements for building • Designer runs analysis on design according to buildingcodes • Building is designed for safety, serviceability, constructability, andeconomy • Client receives final design specifications anddrawings • Designer stores thecalculations StructuralSteel
Detailing Fabricator programs engineer's drawings with software to visualize connections [Daccarett and Mrozowski2002] StructuralSteel
ShopDrawings While detailing, fabricator makes drawingscontaining specifics about how to fabricate each member [Daccarett and Mrozowski2002] StructuralSteel
Fabrication • To achieve its final configuration, the steel maybe • Cut • Sheared • Punched • Drilled • Fit • Welded • Each final member is labeled with a piece mark, length, and job number foridentification. Photo courtesy ofThinkstock [Daccarett and Mrozowski2002] StructuralSteel
Transportation • Members are transportedvia • Flatbedtruck • Train • Waterways Photo courtesyThinkstock StructuralSteel
STRUCTURAL STEELDESIGN ErectionProcess StructuralSteel
Unloading andShake-out • Steel members are unloaded and placed on blocking to allow space for chokers to be easilyattached. • Shake-out: members are sorted on the ground to allow for efficienterection. • [Daccarett and Mrozowski2002] Photo courtesy ofThinkstock StructuralSteel
Picking andHoisting • Cranes lift members intoplace • Hole at end of eachcolumn • After a choker is tied around the center of gravity, multiple beams can be lifted atonce • [Daccarett and Mrozowski2002] Photo courtesy ofThinkstock StructuralSteel
Positioning and InitialBolting • Each beam is lowered into place, and a worker lines it up correctly with drift pins. At least two bolts are attached before the crane releases theload. • – OSHArequirement [Daccarett and Mrozowski2002] Photo courtesy of Daccarett andMrozowski StructuralSteel
FinalBolting • Once everything is in the correct position, the final bolting is performed with a torque wrench or similartool. [Daccarett and Mrozowski2002] Photo courtesy of Daccarett andMrozowski StructuralSteel
STRUCTURAL STEELDESIGN Examples of Prevention throughDesign StructuralSteel
Topics StructuralSteel
Prefabrication • Shop work is often faster than fieldwork. • Shop work is less expensive than fieldwork. • Shop work is more consistent because of the controlled environment. • Shop work yields better quality than fieldwork. • With prefabrication, less work is done at high elevations, which reduces the risks of falls and fallingobjects. [Toole and Gambatese2008] StructuralSteel
Example: PrefabricatedTruss • Fewer connections to make in theair • Safer andfaster Photo courtesy ofThinkstock StructuralSteel
AccessHelp • Shop-installed verticalladders • Bolts on ladders and platforms can be removed later or kept formaintenance Photo courtesy ofThinkstock StructuralSteel
ColumnSafety • Columnsplices • Tabs/Holes for safetylines • Baseplates Photo courtesy ofThinkstock StructuralSteel
ColumnSplices • Have column splice around 4 feet above the working floor • – OSHArequirement Photo courtesy of Bucknell Universityfacilities StructuralSteel
Holes for SafetyLines • Include holes at 21 inches and 42 inches forguardrails • Additional, higher holes can also be included for lifeline support [Gambatese 1996; NISD and SEAA2009] StructuralSteel
BasePlates • Column base plates should always have at least 4 anchor rods boltedin • – OSHARequirement [Gambatese 1996; NISD and SEAA2009; OSHA 29 CFR1926-755] StructuralSteel