Note: The Construction Schedules are useful when performing staged construction analysis for a bridge model. Use the schedules to define (or modify) a construction schedule in a scheduling spreadsheet and to view the schedule in a Gantt chart. CSiBridge automatically creates the required staged construction load cases to analyze the bridge model based on the specified schedule. Staged construction load cases typically use groups to refer to collections of structural objects in the model. CSiBridge allows groups to be defined easily as part of the bridge object definition
Use the Load Case Data - Nonlinear Static Staged Construction form to view and change the definition of a nonlinear direct-integration time-history load case for staged construction. To display the form, click the Analysis > Type > Nonlinear Staged Construction command.
A direct-integration time-history analysis solves equations for the entire structure at each time step, as compared with a modal time-history analysis, which uses the method of mode superposition.
Load Case Name edit box. Use the name shown or type a new name in this edit box. It should be unique among all load cases of all types. Click the Set Def Name button to use a default name for the load case.
Notes Modify/Show button. Click this button to access the Load Case Notes form. Use the form to add notes to the model file specific to this load case.
Design button. Click this button to access the Design Load Type form. Choose Program Determined, or User Specified and then a design type from the drop-down list.
Stage Definition. A Stage is a collection of Operations that are executed at a given time. Each Stage has a defined duration in days that must be an integer greater than or equal to zero. Each Stage starts with initial conditions equal to the end of the previous Stage. The first stage will start with the initial conditions defined for the Staged-Construction Load Case. During the analysis, the model is first adjusted based on specified Operations and then analyzed for time dependent effects based on the duration of the Stage. If output is requested, it reflects the stress and deflection state of the structure at the end of the stage.
Use the Duration, Output Label, and User Comments edit boxes in this area of the form to define the stages in the construction sequence. Specify if output should be provided for the stage by choosing Yes or No from the Provide Output drop-down list.
Add button. Type a value for the number of days in the stage in the Duration edit box; choose to generate output for the stage (Yes) or not (N0); provide an Output Label and any User Comments; and then click the Add button to add a stage. CSiBridge will automatically assign the Stage No.
Add Copy button. Click on an existing entry and then this button to add a copy of the data for that stage to the display list.
Modify button. Click on an existing entry. The data for that stage will appear in the edit boxes at the top of each display area. Type a revised value or comment and then click the Modify button to make the change.
Insert button. Highlight a row of data and use the Insert button to insert a row of data above the row of data highlighted in the display list.
Delete button. Click on the stage definition that is to be deleted and click the Delete button.
Expand Stage Definition check box. Check this check box to display an expanded area for entering Stage Definition data.
Data for Stage area. Use the drop-down lists and edit boxes in this area to specify the type of operation and loading for each stage of construction. Select the stage by clicking on it in the Stage Definition area of the form.
Operation drop-down list. Choose the operation for the selected stage of construction (Add Structure, Load Objects, Load Objects If Added, Remove Structure). The Change Modifiers, Change Releases and Change Section options allow the user to easily review/compare results for alternative property modifiers and frame sections. Use the Type and Name drop-down lists to specify the type of member (frame, cable, area) and the previously defined modifiers to be used for the various stages of construction.
Add Structure -The operation activates the specified Group, Point, Frame, Cable, Tendon, Area, Solid, or Link objects in the model.
Change Modifiers - Applies modifiers to the specified Group, Frame, Cable, or Area objects based on a previously defined Named Property Set.
Change Releases - Applies frame releases to the specified Group or Frame objects based on a previously defined Named Property Set.
Change Section - Assigns a new specified section property to the Group, Frame, Cable, Tendon, Area, or Link object.
Load Objects - Supplies the specified Load Pattern or Acceleration to the Group, Point, Frame, Cable, Tendon, Area, Solid, or Link object. The Load Pattern/Acceleration must be assigned to the object and the object must be active at the end of the Stage in order to receive the load.
Load Objects If Added - Applies the specified Load Pattern or Acceleration to the Group objects. The Load Pattern/Acceleration must be assigned to the object and the object must be activated in the same Stage in order to receive the load.
Remove Structure - Removes the specified object from the model. All loads applied to the Group, Point, Frame, Cable, Tendon, Area, Solid, or Link object also are removed.
Flag as Composite - Indicates that the top slab of a steel I-girder bridge deck section is acting compositely for design purposes when performing a bridge design check of type "Steel-I Comp Construct Stgd". See Notes for operation Unflag as Composite.
Unflag as Composite - Indicates that the top slab of a steel I-girder bridge deck section is not acting compositely for design purposes when performing a bridge design check of type "Steel-I Comp Construct Stgd". Notes for Flag/Unflag as Composite: These two operations can only be applied to bridge groups of type "Top Slab" or "Mixed" (that include top-slab items) in bridge objects containing a steel I-girder deck section, or to group "ALL" if the model contains a steel I-girder deck section in any bridge object. These operations are only used for bridge design and have NO EFFECT on analysis results. It is still necessary that the staged-construction load case perform other operations as described above to simulate the placement and hardening of the concrete. The default for the entire model is "Unflag as Composite,, meaning that the design will assume non-composite action until the Flag as Composite operation has been applied.
Set Traveler for Segment - Add or move the specified traveler to support the specified bridge span segment that is going to be erected/casted. The traveler will be attached to both the specified new segment and the adjacent supporting segment that is assumed to have been previously erected. The same traveler can be repeatedly assigned to unerected bridge span segments based on the desired construction sequence. The traveler will remain in the model until it is removed. This operation is only available for segmental bridge objects with at least one bridge traveler defined.
Remove Traveler - Remove the specified traveler from the model. This operation is only available for segmental bridge objects with at least one bridge traveler defined.
Note: Area uniform loads to frames are applied by specifying the associated frame objects, individually or in a group, rather than the loaded area objects. This means the frames could be loaded before the areas are added, or the load would not be added if the areas were present but not the associated frames. To help control this, assign the area uniform load to frames loading to a separate load pattern and use the Load Objects operation once the areas have been added to the model. The Load Objects if Added command should only be used in this case if the area and associated frame objects are added at the same time.
Object Type drop-down list. Select the group, point or frame to be included in the stage.
Object Name drop-down list. Select the name of the object to be included in the stage from this list.
Age at Add edit box. This edit box is available when the Operation selected is Add Structure. Enter a value for the age of the structure when it is/was added.
Type drop-down list.
If the Operation is Change Section, select the object type to be changed from the Type drop-down list and then select a revised section property from the Name drop-down list.
If the Operation is Load Objects or Load Objects If Added, choose the type of load from the Type drop-down list (load pattern or an acceleration) and then select the load from the Name drop-down list, and as required, specify a Scale Factor to be applied to the load in the edit box.
After providing the necessary data, click the Add button to add the load definition to the specified stage of the construction sequence. Click on existing data, revise the data and click the Modify button to make the change. Click on existing data and click the Delete button to delete a load definition.
Expand Stage Data check box. Check this check box to display an expanded area for entering the Data for each Stage.
Show Stages in Tree View button. Click this button to display the Staged Construction Tree form, which shows the stage definition in tree form. The expanded tree will display the Stage number, any user comments, the data specified by stage in the Data for Stage area (i.e., the operation being performed, the objects affected, the age of any added structures at the time those structures were added, any loading and scale factors), and Start Times based on the schedule of days specified in the Duration edit box for each stage. For example, if Stage 1 had a duration of 3 days, Stage 2 has a Start Time of 3 days. If Stage 2 then has a duration of 5 days, Stage 3 will have a Start Time of 8 days, and so on.
Note: When the Show Stages in Tree View button is clicked, CSiBridge may display a message indicating that time dependent information has been specified and that the flag to consider this information is set to off. To turn this flag on so that those time dependent properties can be included in the analysis, click the Nonlinear Parameters Modify/Show button (see below) to access the Nonlinear Parameters form; check the Time Dependent Material Properties check box.
Results Saved. Click the Modify/Show button to access the Results Saved for Nonlinear Static Load Cases form and specify the results to be saved for the analysis.
Nonlinear Parameters. Click the Modify/Show button to access the Nonlinear Parameters form and specify the Nonlinear Parameters to use for the analysis.