Loads
Loads in Substructure are specified in distinct load cases corresponding to load types specified by IRC Standards . All loads may be manually input. However, Substructure can generate most commonly encountered loads automatically.
It is, however, the user's choice to use this generation. For specific cases, the user may want to input already computed loads directly, even for the load types that the program can generate. All other loads, when needed should be manually input.
The program generates the following loads:
- Self Load of the Pier
- Dead Load of the Superstructure
- Live Load
- Longitudinal Force/Braking Load
- Centrifugal Load
- Wind Load on Structure
- Wind Load on Live Load
- Temperature Loads from Superstructure
The results due to these loads are visible to the user after a successful completion of the analysis. These analysis results can be seen under the "self load" case.
In the generation of these loads, the entire cap load is applied to the internal model on cap elements. For column members, the load is generated to the bottom of the cap and applied to the column elements. The weight of the column is generated from the bottom of the column to the cap bottom where the centerline of the column intersects. In rare cases where the column is wider than the cap and extended above the cap bottom, the self-load of the part wider than the cap is ignored for the part above the cap bottom line.
| Nomenclature | |
|---|---|
| Slab weight | Unit weight of a slab. |
| Girder weight | Unit weight of a girder. |
| Wearing surface weight | Linear load for wearing surface. |
| Barrier load | Linear load for a barrier. |
| Multiplier | A factor multiplied to current loads. |
| Bearing load | Load acting on bearing points. |
| Cap load | Load acting on centerline of a cap. |
| Arm | Distance between centerline of cap and point of load. |
| Column load | Load acting on column. |
| Dir | Direction of column load, either in global X, Y, or Z direction. |
| Mag 1 | Magnitude of column load at starting point. |
| y1/L | Location of column load at starting point, in terms of column length, measured from the fixity point of a column (i.e., bottom of the column.) |
| Mag 2 | Magnitude of column load at ending point. |
| y2/L | Location of column load at ending point, in terms of column length, measured from the fixity point of a column (i.e., bottom of the column.) |
| Angle of wind | Angle of winds acting on a bridge, measured from the normal to a bridge longitudinal direction to the wind pressure direction. Positive if anti-clockwise. |
| Elevation above which wind load acting | Define the elevation, above which the wind load is applied on column. |
| Live load length | Length of live load; default value is average span length. |
| Library load | Live load designation selected from Live Load Library. |
| Importance classification | Used to determine the Seismic Performance Category for seismic load generation. |
| Unit weight of superstructure | Linear superstructure unit weight. |
| Iy of superstructure | Moment of inertia of superstructure about global Y-axis. |
| Iz of superstructure | Moment of inertia of superstructure about global Y-axis. |
| Span number rear to current pier | Span number at back of pier under consideration. |
| Avg. height | Average height of all columns for pier under consideration (0 if abutment.) |