basculement

Basculement is the act or result of tipping, tilting, or overturning a body from one stable position to another, typically by rotation around a pivot edge or hinge. The term covers both accidental and intentional motions and may refer to the movement itself as well as the final orientation. Etymologically, basculement derives from basculer, meaning to topple or tilt.

In mechanical and civil engineering, basculement is used to describe motions in which parts pivot, such as the deployment of a bascule mechanism or a bascule bridge, where a deck rotates about a hinge and is often counterweighted. The term can also describe the overturning of structures or components under load conditions or during movement.

In transportation and safety, basculement often refers to a rollover, when a vehicle tips onto its side or roof, as a result of high speed, evasive maneuvers, or uneven load distribution. The concept is analyzed in terms of stability angles and the vehicle’s centre of gravity.

In geology, basculement denotes the overturning or tilting of rock layers due to tectonic forces, which can invert strata and affect stratigraphic interpretation.

The term is sometimes used interchangeably with renversement or capotage in some contexts, though basculement emphasizes the action of tipping or overturning rather than the resulting state alone.