History of Live Loads
History of Live Loads
(OP)
Has anyone ever come across an article or publication which documents the history of live loads in prominent building codes throughout the past century?
Seems like this could be valuable information for renovation projects when you are trying to determine for which load the structure should have been designed.
Seems like this could be valuable information for renovation projects when you are trying to determine for which load the structure should have been designed.






RE: History of Live Loads
RE: History of Live Loads
Forensic Structural Engineering Handbook
Robert T. Ratay, Ph.D., P.E., Editor-in-Chief
McGraw Hill
Has a section 2.1 on codes and standards in the US. Even if you may not find there directly the values, you will find guide to the original documents to then trace them. As a example, I quote...
"A report of the Department of Commerce Building Code Committee, entitled "Minimum Live Loads Allowable for Use in Design of Buildings," was published by the National Bureau of Standards in 1924. The recommendations contained in that document were widely used in revision of local building codes.
These recommendations, based upon the engineering data available at that time, represented the collective experience and judgment of the committee members responsible for drafting this document. The ASA Committee on Building Code Requirements for Minimum Design Loads in Buildings subsequently issued a report in 1945 that represented a continuation of work in this field. This committee took into consideration the work of the previous committee, and expanded on it to reflect current knowledge and experience.
The end result was the American Standard Building Code Requirements for Minimum Design Loads in Buildings and Other Structures, A58.1-1945.8 The A58.1 standard has been revised five times since 1945, the latest revision9 corresponding to ASCE 7-95, Minimum Design Loads for Buildings and Other Structures.* Subsequent to the 1982 edition of ANSI A58.1, the American National Standards Institute (ANSI) and the ASCE Board of Direction approved ASCE rules for the standards committee to govern the writing and maintenance of the ANSI A58.1 standard. The current document prescribes load combinations, dead loads, live loads, soil and hydrostatic pressures, wind loads, snow loads, rain loads, and earthquake loads. Like earlier editions of the ANSI standard, ASCE 7 has significantly influenced the development and revision of other building codes."
More in the book.
RE: History of Live Loads
ABP...Good thread. Something that all of us in the forensic world struggle with almost daily.
Two older government agencies in the US, the Bureau of Mines and the Bureau of Reclamation, had early published documents that were commonly followed by engineers, in the absence of specific code requirements.
Regional and national model codes came much later. Most codes early on were local.
One other consideration you have to make is the applicability of a particular version of the code for the area. Keep in mind that a model code has no validity until adopted by ordinance or statute. Further, many jurisdictions were routinely behind in their adoption of a particular code. For instance, assume the design was done in 1977 in the southeastern US. One would logically assume that the last edition of the Standard Building Code (at that time, called, the Southern Standard Building Code)would prevail. Not so. The local group might have last adopted by ordinance, a code from the 60's.
To further complicate the issue, particularly around code edition change times, is that the date of application for a permit is the selector of the code edition to be followed. So if construction was done in 1998, one might assume the 1997 version of the Standard Building Code might be used. Well, if the date of application pre-dates the adoption of the code or the issuance of the code, the previous edition is the one that would be used.
Ain't life fun in this business??!!
RE: History of Live Loads
RE: History of Live Loads
Maybe 100 years from now, engineers will have electronic copies of plans and specs to review on their renovations jobs.
RE: History of Live Loads
RE: History of Live Loads