Pennsylvania Act 1929-129 — STRUCTURAL STEEL STANDARDS IN FIRST CLASS CITIES

Act text

AN ACT

Prescribing the maximum allowable stresses to govern the design and erection of structural steel in buildings in cities of the first class.

Section 1. Be it enacted, &c., That from and after the passage of this act, the following allowable stresses shall govern the design and erection of structural steel in buildings in cities of the first class:

Section 2. All parts of the structures shall be so proportioned that the sum of the maximum static stresses, in pounds per square inch, shall not exceed the following:

Compression in columns

18000

= ----------

L squared

1 + ----------

18000 r squared

With a maximum of 15,000, in which L is the unsupported length of the column, and r is the corresponding least radius of gyration of the section, both in inches.

When a structural steel column is encased in stone concrete properly reinforced, the radius of gyration of the combined section may be used, and the above maximum stress may be disregarded.

For main compression members, the ratio L/r shall not exceed 120, and for bracing and other secondary members 200.

Section 3. Every steel floor beam, in any building hereafter erected or altered, used for any business purpose, shall be capable of sustaining a live load, concentrated at its center, of at least four thousand pounds.