ABSTRACT
The study of forces acting upon objects at rest is called ‘statics’; a knowledge of the principles of statics is essential for an understanding of structure. Any system of co-planar forces acting on a rigid body in equilibrium must satisfy the several equations of equilibrium. A body supported by less than three reaction components is statically unstable under a general system of co-planar forces. The forces that produce Bending Moments are in the same plane as the structure, and the deformation that results in the structure is curvature. These forces include the pressure of wind, the weight of rainwater on the roof, the weight of the occupants, the forces produced by earthquakes, even the weight of the building itself. There are many examples of concurrent forces in the primary structural frame of the Hong Kong and Shanghai Bank building in Hong Kong.
