Product(s):	SACS
Version(s):	All.
Area:	GAP

Problem

In the gap analysis, I see additional loads like G001, G002 are reported in the output listing file. For example, if I see SACS Gap Manual, Sample Problem 1, it has 2 basic load cases and 2 combination cases as below.

However, in the output listing the LOAD CASE STATUS REPORT, there are additional 4 load cases G001 to G004 reported as below.

What is the significance of these additional loads?

Solution

These G series loads are dummy load cases. The load cases starting with GXXX are autogenerated dummy unit load cases. The applied load summary shows the total load as zero because these load cases are for internal use only. 

 

The theory behind this is, in short, the load factors for the unit load cases are adjusted (or calculated) till the gap condition (tension/compression only etc.) is satisfied. You can read more in detail in the commentary sections 3.1 and 3.2 of the Gap manual.