Engineering and Construction

The first type of settlement is directly caused by the weight of the structure. For example, the weight of a building may cause compression of an underlying sand deposit or consolidation of an underlying clay layer. The settlement analysis must include the actual dead load of the structure. The dead load is defined as the structural weight due to beams, columns, floors, roofs, and other fixed members.

Live loads are defined as the weight of nonstructural members, such as furniture, occupants, inventory, and snow. Live loads can also result in settlement of the structure. For example, if the proposed structure is a library, then the actual weight of the books (a live load) will contribute to the settlement of the structure. Likewise, for a proposed warehouse, it may be appropriate to include the actual weight of anticipated stored items in the settlement analyses. In other projects where the live loads represent a significant part of the loading, such as large electrical transmission towers that will be subjected to wind loads, the live load (wind) should also be considered in the settlement analysis.

In summary, the load used for settlement analyses must consist of the actual dead weight of the structure, and in many cases, will also include live loads. Considerable experience and judgment are required to determine the load that is to be used in the settlement analyses.