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| Relief. Cards will replace 220-page text for simple steel frame design, say steel spec writers. |
"Youre in big trouble if you design a new building structure and dont meet the letter of the code," says Schwinger, quality assurance manager at Cagley Harman & Associates, King of Prussia, Pa. "Even if there is no real problem, there could be potential serious ramifications from a liability standpoint."
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| Schwinger |
Increasing code complexity has given Schwinger and other designers "in the trenches" a bad case of code anxiety. "The problem is reaching a critical mass," he says.
Engineers get "stomach knots" from overly complex equations; unclear language and poor explanations. They also complain about code cycles that are too short, making it virtually impossible to keep up with changes. And many object to code committees packed with engineers, including managers and academics, who dont actually use the codes on a day-to-day basis.
Time spent deciphering codes is time away from creating quality designs, say sources. Incomprehensible codes help no one "except the lawyers," says Schwinger.
When Schwinger solves a code conundrum, he e-mails a "TEK note" to 31 people in his office. Since 2001, he has written 700 notes. TEK 568 was on large uplift forces on column base plates. TEK 581 was on clear cover to reinforcing steel in shear walls. TEK 587 was on efficient structural steel connections.
Not all firms have or can afford a Schwinger. Perhaps thats why James B. DeStefano, senior partner of the Fairfield, Conn., firm bearing his name, thinks its only "a matter of time" before a major structural collapse results from a building code misinterpretation.
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| Stacking Up. Old concrete and steel standards (two on top) contrast with current codes in size and in complexity of content. |
Labyrinth of Provisions
Others agree. Maneuvering through the labyrinth of provisions can lead the engineer to lose sight of critical "big picture" issues, including overall stability and punching shear, says Aine Brazil, a managing principal of Thornton-Tomasetti Group, New York City. "Codes and commentaries do very little to give direction on priorities," she says.
An increasing reliance on computers, especially among young engineers, to solve the complex code equations also is a concern. "Complex formulas practically require the use of spreadsheets and eliminate the ability of the engineer to get a feel for the design," says Brazil.
That can lead to errors. To guard against this, some firms still insist engineers do manual calculations to verify globally the computer results.
Schwinger and others suffering from code trauma do not consider themselves Luddites against change. Research on the real behavior of structures needs to continue, many agree. "But engineers in the trenches need this research synthesized down to relatively straightforward, simplified design criteria and formulas," says Robin A. Kemper, assistant director of the structures division of French and Parrello Associates, Holmdel, N.J. That isnt happening, she says.
Frustration is not limited to engineers in the trenches. Jonathan C. Siu, principal engineer of the Dept. of Planning and Development, Seattle, says his staff and some principals of local firms tell him that increasing code complexity, especially in wind and seismic design, "is not increasing the chances of getting to a correct or consistent answer." Its the opposite, says Siu.
Code complexity has been increasing since the 1970s, and so have complaints. But sources say the code quagmire is exacerbated recently by "hyper-track" job schedules, slashed fees and a "tsunami" of work.
The transition to the model International Building Code, published by the International Code Council and adopted so far by jurisdictions in more than 40 states, isnt helping in the short run. Already there are different versions of IBC, intended as a unified model code, in New York, New Jersey, Ohio and other states. Malcolm G. McLaren, president and CEO, McLaren Engineering Group, West Nyack, N.Y., says "a truly universal building code would be helpful," but would require the cooperation of state and local regulators.
IBC references structural and materials standards. The standard that stresses engineers the most is ASCE 7-02, Minimum Design Loads for Buildings and Other Structures, published by the Structural Engineering Institute of the American Society of Civil Engineers. The three main materials standards present fewer difficulties, say engineers. They are the American Concrete Institutes Building Code Requirements for Structural Concrete and Commentary (ACI 318-05), The American Institute of Steel Construction Inc.s 2005 Specification for Structural Steel Buildings (AISC 360-05), and the Masonry Institute of Americas 2003 Masonry Codes and Specifications.
Even so, Schwinger says ACI 318, sections 10.10-10.13, which deal with slenderness and stability of compression members, has good information that is not explained well. And he has problems with confusing column buckling equations in the third edition of AISCs load and resistance factor manual.
Code-writing committees should not be adding more coefficients and parameters to formulas unless they would have a real and significant impact, many say. For a 5-10% variation in results, the refinement does not seem worth the increased chance of messing up the calculation and using very erroneous values," says Brazil.
John G. Tawresey, a vice pres- ident in the Seattle office of KPFF, thinks all proposed code additions should be trial-designed. Tawresey, long active in the code arena, has a "litmus test" for whether a proposed regulation should be adopted: Can it be enforced by the building official? Is it a result of unsubstantiated research? Has it been too compromised by the politics of the process? Has it been trial-designed? "If the answers are yes, no, no and yes, the regulation passes my test for simplifying the code," he says.
Another veteran of code wars, Lawrence G. Griffis, president of the Austin-based structures division of Walter P. Moore & Associates Inc., adds two more questions: Does the proposed change have an impact on life safety? What is the economic impact of the change?
Griffis wants a standard format developed to justify a specific change. "Code changes must only occur within the national technical bodies responsible for them," he says. "Local code bodies [should not] be allowed to make technical changes to a national standard without going through a predefined process."
Many call for more research dollars to vet proposed changes. Standardization of the commentary format is also needed, as are user guides, say sources. And, in general, engineers should spend more time on training and education.
Trial Designs
To test code provisions, Tawresey spearheaded formation of SEIs trial design program, another all-volunteer effort. Since, 1998, six have been done.
In the fourth, engineers were given a shear wall elevation with a foundation and asked to find the footing length based on allowable soil pressure and the factors of safety against sliding and overturning, both for wind and seismic forces. The 13 respondents used six different codes to come up with solutions. Nine had a 14-ft-long footing; four had 12 ft.
The effects of overturning were not included in the four solutions, which indicates 30% did not perform the engineering fundamental basics, says the report on the trial design. The use of load combinations was also not consistent.
"Weve learned that the code is interpreted differently throughout the U.S., that the language of the code is not clear and concise and that the code is taking the...
ntil recently when he started running marathons, structural engineer Clifford W. Schwingers only true obsession was cracking the mysteries of the codes. Deciphering complexities and clarifying ambiguities in building design standards is not exactly Schwingers idea of a good use of time. But he does not expect his compulsion to subside until there is code reform.
