What does in-plane discontinuity in vertical lateral-force-resisting elements indicate?

The identification of in-plane discontinuity in vertical lateral-force-resisting elements often relates to the configuration and behavior of a structure when subjected to lateral loads, like those from wind or seismic activity. An offset greater than the length of the elements signifies a significant architectural or structural change that could adversely affect the structural integrity during lateral loading.

When the offset is larger than the length of the resisting elements, it can create forces that the structure was not designed to handle, leading to weakened connections and an increased likelihood of failure. This type of configuration can disrupt the expected load paths and create vulnerabilities, leading to an overall reduction in the stability and performance of the structure.

In contrast, a consistent lateral-force system would indicate that the elements are adequately aligned and can provide the intended resistance to lateral forces. A weak storey configuration refers to a distinct weakness in certain levels of the structure that could cause disproportionate response under loading, while the notion of offsets being less than the element length indicates that there is sufficient contact and integration across the vertical resisting elements. Thus, recognizing an offset greater than the length of the elements signals an important concern for the structural assessment and further design considerations.