ILM Bridge Stage Wizard

Boundary Group

Select the boundary group considering the piers and buttresses of the completed bridge of the final structure system. When defining ILM Stages, only the boundary conditions relevant to the individual construction stages are automatically considered by reflecting the boundary group. That is, as the construction stages progress, each stage becomes corresponded to a boundary condition contained within the boundary group.  

Specify the direction of launching and the distance, which are reflected at the time of auto-generating and defining construction stages. The launching distance and direction are automatically calculated on the premise that the Reference Node is launched from the Start Node to the End Node.

Reference Node

Assign the node, which will be referenced to determine the direction of launching. The node number corresponding to the front end of the launching nose is assigned as the reference node.

Start Node

Assign the node location from which the referenced node starts moving. That is, the node of the front end of the launching nose is assigned at the first construction stage.

End Node

To define the direction (vector) of launching, assign a node, which sets the direction from the Start Node.

Radius

Specify the radius of the curvature if the main girder retains a curved profile in plan. The radius must coincide with that defined in the ILM Model tab if the ILM Bridge Model Wizard is used.

CCW : Launching counter-clockwise (Concave curvature)

CW : Launching counter-clockwise (Concave curvature)

The extrusion distance and direction are automatically calculated based on the fact that the reference node is extruded from the start node to the end node.

Specify a tolerance value within which an eccentricity between the location of an element node and a boundary location (piers and abutments of the completed structure) can be ignored during launching. Refer to the diagram.

The eccentricity (e) must be equal to or less than the permissible tolerance (T). (e≤T)

Assign launching information and additional boundary conditions to be considered when generating construction stages for each segment.

Define

In order to modify or add launching data, select the desired construction stages in the list of the dialog box and click the button to enter the following items:

Delete

Select the desired construction stages from the list and click the button to delete the launching information corresponding to the selected construction stages.

Define Launching Information dialog box

Launching Information

Distance

Input the launching distance for the segments of the selected construction stages. In general, the segment length is specified. In the case of the last segment, the launching distance must include the segment length itself as well as the additional length required to completely clear the temporary piers and the fabrication plant supports so that the end of the segment reaches the end buttress.

When the launching distance is entered, the ILM Stage Wizard auto-generates and defines the sub-construction stages reflecting the currently activated boundary conditions for each step of launching. The main construction stages represent the stages when the segments are completed at the prefabrication plant, and a number of sub-construction stages equal to the number of launching steps are generated. The last step of the auto-generated steps signifies the time of completing the launching of the corresponding segment. The duration entered for the main stage applies to the last sub-stage.

A letter 'P' is assigned to some sub-construction stages additionally generated in the boundary groups and construction stages, which are auto-generated upon executing ILM Stage Wizard. These sub-stages represent the moments just before the piers and buttresses support the launching nose. That is, these sub-stages are additionally defined to represent the moments when the cantilever becomes the longest immediately prior to being supported by each support. The next stage immediately after the sub-construction stage retains the identical condition except that a support is provided to the frond end of the launching nose. Refer to Define Construction Stage for stages auto-generated by the Wizard function, Define Boundary Group for the boundary groups and Define Load Group for the load groups.

Step

Specify the number of times required to launch the bridge over the Distance.

Save Stage Result

Check on to save the analysis results for each construction stage.

Save Step Result

Check on to save the analysis results for each construction step (sub-stage).

Boundary Group for Temporary Support

Activate or deactivate additional boundary groups encountered during the construction stages such as the temporary piers and fabrication plant supports. The additional boundary groups must be defined prior to executing ILM Stage Wizard, and they are reflected in the auto-generated sub-construction stages.

In the event that ILM Bridge Model Wizard is used, Element groups, Boundary groups and Load groups are automatically generated.

If you modeled a bridge using the ILM Bridge Wizard, the automatically generated group names are as follows:

Structure Group

Nose : Launching nose (Activate at construction stage CS1)

Segment n : nth segment (Activate at construction stage CSn)

Bridge Girder : All the main girder except for launching nose

Boundary Group

Final : Boundary conditions of Final System

Temporary : Temporary boundary conditions

CSn-Dfmm

Boundary conditions at construction stage CSn-m (Assigning deformation points)

CSn-Orgm

Boundary conditions of construction stage CSn-m (assigned at the initial position)

Boundary conditions right before the beginning of launching nose is supported by the bridge pier. (activated in construction stage CSn-mP and deactivated in the next stage)

CSn-OrgmP

Boundary conditions in which the end of launching nose is supported by the bridge pier. (activated in construction stage CSn-m after CSn-mP and deactivated in the following stage)

The construction stage CSn-m, where "m" is a sub-stage created based on the extrusion distance of the nth segment.

The construction stage CSn-mP is an additional sub-stage created to reflect the most unfavorable condition, where the beginning of launching nose is supported by the bridge pier just before cantilever length reaches its maximum.

Load Group

Self Weight : The self-weight of an element (activated in construction stage CS1 and applied simultaneously with the creation of elements).

TB-Prestress n : Prestress of the primary tendon (T/B) being tensioned in construction stage CSn.

Web-Prestress : Prestress of the secondary tendon (counter tendon) activated in the final construction stage just before completion.