Читать книгу Strength Of Beams, Floor And Roofs - Including Directions For Designing And Detailing Roof Trusses, With Criticism Of Various Forms Of Timber Construction - Frank E. Kidder - Страница 18

The strength of a floor evidently depends upon the strength of the joists, headers, trimmers and girders of which it is composed, and more especially on the weakest of these, in the same way that the strength of a chain is determined by the strength of its weakest link. The joists, headers, trimmers, etc., taken as single pieces, are simply wooden beams, and their strength may be computed by the rules given in Chapter I.

The application of these rules to floors, however, may not be readily apparent to every one, and in some cases it is possible to give special rules which are more convenient to use for floors, so that a few examples, showing the method of determining the strength of floors, may prove of interest to the readers of this volume.

In dealing with “the strength of floors,” we have two different problems to consider: (1) to determine the strength of a floor already built, or planned, and (2) to determine the size of beams to support a given load, with a given span. In this chapter we will consider the first of these problems—that is, to determine the strength or safe load of a given floor.