Construction Stage Analysis
The command provides a means to assign stage numbers for diaphragms and to define duration information for each stage.
Stage duration is defined in days and this information is used while calculating effects of concrete material changes such as deformations due to creep and shrinkage as well as changes in concrete modulus of elasticity over time. Duration information can be ignored if time-dependent material effects are not considered in analysis.
| Setting | Description |
|---|---|
| Number of Stories/Stage | Type a integer of 1 or greater to group stories into a single stage for automatically generating stage numbers. |
| Generate Stages | Click to assign stage numbers for each diaphragm automatically. Additionally, you can modify the assigned stage numbers or type a unique stage number to any diaphragm in the table. |
| Duration | Enter duration information in days for each stage. |
Upon closing the Stage and Duration dialog, the program also assigns stage numbers to members including gravity members (see the option in the Story Diaphragm dialog for Gravity Members supporting two-way decks.). This type of assignment is regarded as global (default) setting for stage numbers of members. If a member is already assigned a stage number before, it is preserved and not changed upon closing the dialog.
With global setting, members located within a diaphragm are given the same stage number of the diaphragm. Those outside of any diaphragm, the program uses stage number of first diaphragm at the level of member (in case of a level with no diaphragm at all, the program uses story number as stage number). It is always possible to override the global setting via command.
The command provide a means to define concrete material models that are used to calculate time-dependent material effects for concrete members in construction stage analysis (i.e., effects of aging of concrete modulus, creep and shrinkage deformations). This section can be skipped if no time-dependent effects are included in stage-construction analysis.
Three different concrete models are implemented: ACI 209R-98, CEB MC90-99, and Model B3.
For each concrete model, a set of default settings is provided (named with Label DEFAULT). You can also create concrete models with different parameters by providing a unique label.