TABLE OF CONTENTS The calculation of design loads for buildings is covered in this chapter and Chap. 3. Chapter 2 deals primarily with Code-required design loads and forces and how these are calculated and modified for a specific building design. Chapter 3 is concerned with the distribution of these design loads throughout the structure.
In ordinary building design, one normally distinguishes between two major types of design criteria: (1) vertical ( gravity) loads and (2) lateral forces. Although certain members may function only as vertical-load-carrying members or only as lateral-force-carrying members, often members may be subjected to a combination of vertical loads and lateral forces. For example, a member may function as a beam when subjected to vertical loads and as an axial tension or compression member under lateral forces (or vice versa).
Regardless of how a member functions, it is convenient to classify design criteria into these two main categories. Vertical loads offer a natural starting point. Little introduction to gravity loads is required. Weight is something with which most people are familiar, and the design for vertical loads is often accomplished first. The reason for starting here is twofold. First, gravity loading is an ever-present load, and quite naturally it has been the basic, traditional design concern. Second, in the case of lateral seismic forces, it is necessary to know the magnitude of the vertical loads before the earthquake forces can be estimated.
The terms load and force are often used interchangeably. Both...
