What are considered vertical loads in building structures?

Vertical loads in building structures refer to forces acting downwards due to gravity. These loads are crucial in determining how a structure will perform under such influences. The correct option includes gravity, dead loads, live loads, and impact loads as components of vertical loads.

Gravity refers to the weight of the building and its occupants acting downward. Dead loads encompass the permanent static forces due to the weight of the structural components themselves, such as beams, walls, and roofs. Live loads consist of dynamic forces from occupants and movable items within the structure, like furniture. Impact loads describe sudden forces that can occur, for example, when heavy machinery is dropped or people jump.

The other options describe forces that are not categorized as vertical loads. Wind and seismic forces relate to lateral loads due to environmental phenomena, whereas sliding and twisting forces indicate horizontal actions, and weight of the roof only does not encompass the entirety of vertical loads as it fails to consider the contributions from other elements and types of loads. This distinction is important for structural engineers and rescue technicians to understand when evaluating building integrity and planning rescue operations during structural collapse scenarios.