The results reported for individual stages of a staged construction load case are cumulative results (for example, results for stage 2 contain contribution from both stages 1 and 2). If you need to obtain only response due to the loading applied in a particular stage, you could use one of the following approaches:
- Post-process SAP2000 results. To obtain results for stage n, subtract results for stage (n-1) from results for stage n.
- Redefine the single staged construction load case as a chained sequence of load cases, each using stiffness at the end of the previous case. Then setup a load combination to obtain results only for a given stage n as follows:
- results for stage n only = (cumulative results for stage n) - (cumulative results for stage (n-1))
The second approach is illustrated in the attached as shown on the screenshots below:
The model is a horizontal cantilever with point load in gravity direction applied to the free end:
In a staged construction load case STAGED, incremental loads of 1kN, 10kN and 100kN are applied in stages 1, 2 and 3:
To obtain noncumulative results only for stages 2 and 3, setup a single-stage staged construction load cases "STAGED stage 1", "STAGED stage 2", and "STAGED stage 3" that are equivalent to the STAGED construction load case, but the loading is represented as a chained sequence of separate load cases rather than a single load case.
Then setup load combinations "stage 1 only", "stage 2 only" and "stage 3 only" as described above to obtain noncumulative results for each stage. The figure below shows that results are as expected:
- [SAP2000 V14.2.4 model|^cantilever model V14.2.4.zip] (zipped SDB file)