b'YOUR TOOLKIT FOR BUILDING EXCELLENCEstructural analysis). Step 3: Select components anddesigned to handle all load combinations to which connections capable of handling the forces to whichit could be subjected. Total ignorance of applicable they will be subjected. In practice, selections madeloads and load combinations is a hallmark of non-in Step 3 will influence structural analysis (Stepengineered building design and explains why so 2) and this makes structural design an iterativemany agricultural buildings are damaged by wind process.and unbalanced snow loads that would not damage It follows that a fully engineered building is aa fully engineered agricultural building. building in which the interaction of all structuralExtremely weak connections between components components is properly accounted for duringis another hallmark of non-engineered structures. structural analyses, and forces resulting fromThe stresses that surround mechanical fasteners these analyses are used to size all components. By(bolts, screws, nails) are complex and control contrast, the design process of a non-engineeredfastener size, spacing and placement relative building does not account for component loads orto the ends and edges of the components they actual component strengths. A partially engineeredconnect. These conditions are seldom realized by building lies somewhere between these twobuilders attempting to mirror the design of another extremes.building. Improperly assembled connections trigger The collapse of the Myren freestall barn, like thatand/or contribute to many building failures. of five other collapsed buildings I inspected the same day, was triggered by unbalanced snow loads (i.e., drift and sliding snow loads) that each of the structures should have easily withstood. In all six cases, it was obvious the building was not fully engineered. This lack of engineering can be attributed to the fact many companies involved in agricultural building construction do not employ engineers, nor do they hire an engineer to perform structural engineering calculations for the agricultural buildings they construct. Each year this results in the construction of numerous agriculture buildings that contain multiple components not sized to handle the loads the building is expected to experience. Myriad problems Companies that erect non-engineered buildings generally try to emulate designs they have seen elsewhere. This causes a myriad of problems. Simply copying, altering and/or scaling up anFigure 1: Buckling of a nail-laminated post due to improper existing design completely ignores the fact thatdesign. Also visible is the buckling of the compression web loads like wind and snow are highly dependentchords due to improper bracing.on the size, shape, orientation and location ofMany building companies are established by a building as well as characteristics of the localindividuals who begin erecting buildings for topography and the size, shape and orientation ofa company that employs engineers and sells attached and surrounding structures. Additionally,fully engineered packages. While I applaud the snow, wind and other structural loads act in aentrepreneurialism of anyone starting their own variety of combinations and a building must be continued on page: 30 FRAME BUILDER - VOL6 5 / 29'