Major Changes to Physical Model

Major changes in the physical model (from OBM) will result in the reset of the various parts in superstructure and substructure of the analytical model.
- For superstructure, the following changes in the physical model will be considered as the major changes.
  - Change in the number of bridge spans
  - Change in the number of beams. If number of beams change in only in one span and the number of beams in the other spans stay the same, the major change is only applicable to the span whose number of beams change.
  - Change in the beam type
- The following reset in the related analytical model of superstructure are expected as the results of the major changes.
  - Loads, reinforcement and analysis options are reset
  - Note: Loads are excluding the self-weight of the members. Self-weight of the members will be recalculated automatically regardless of major or minor change.
  - Analysis/Design results are reset
  - If a bridge consists of multiple spans (or groups), the major changes in only one of the spans (or groups), will result in:
    - Reset of loads, reinforcement and analysis options selected for the span (or group) that major changed occurred.
    - For the rest of the spans (or groups) where there is no major change occurred, loads, reinforcement and analysis options selected for the span (or group) will not reset.
    - Global analysis options (such as ASD/LFD/LRFD options or Line/Grillage/FEM option) will not reset.
- For substructure, the following changes in the physical model are considered as the major changes.
  - Change of bent type: e.g., from hammer head to wall pier
  - Change of cap shape: e.g., from tapered to inverted tee
  - Change of column shape: e.g., from rounded to rectangular
  - Change of footing shape: e.g., from spread footing to drilled shaft
- The following reset in the related analytical model of substructure are expected as the results of the major changes. Particularly, the reset will be controlled differently for different substructure components. Typically, the setting/configurations of both analysis and design check shall remain the same regardless the reset of loads, load combinations, analysis results, and steel configurations
  - Level 1 reset - the settings/configurations for both analysis and design check, including design code, the state option, settings in A/D Parameters window, loads, load combinations, analysis results, and steel configurations for the whole substructure
  - Level 2 reset - analysis results for the whole substructure
  - Level 3 reset - steel configurations for the related structure components
    So,
    - Change of bent type will trigger Level 1 reset
  - Change of bent cap will trigger (Level 2 reset) + (Level 3 for cap only)
  - Change of bent column will trigger (Level 2 reset) + (Level 3 for column only)
  - Change of bent footing will trigger (Level 2 reset) + (Level 3 for footing only)