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Plan Irregularity Type 5

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A question has arisen recently among a few engineers locally about the meaning of a Type 5 plan irregularity.  I have always thought of this as a non-orthogal systems irregularity, but looking at ASCE 7-02 Table 9.5.2.3.2, the definition is: "The vertical lateral force-resisting system elements are not parallel to or symmetric about the major orthogonal axis of the lateral force resisting system."  The interpretation, that had never occured to me, is that the "or" in the sentence means that it applies to either non-parallel systems or non-symmetric systems.  Since 95% of layouts are not perfectly symmetric, 95% of buildings would have a Type 5 irregularity.  I have not understood this to be the meaning of the irregularity, but I don't see how I can adequately explain the "or symmetric" part.  Does anyone have any insight into this?  

Paul
  


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