ILM Model
Auto-generate a bridge model by entering the material properties and sections of the main girder and launching nose, launching distances, division of segments, duration of stages, etc.
ILM Model Wizard dialog box
Bridge Information
Element Length
Launching distance per segment, length of an element
The lengths of the segments and launching nose are multiple of the one-time launching distance, which is defined in Define Launching Information of ILM Bridge Stage Wizard.
Radius
Check on to specify the radius of a curved bridge with a single curvature, which applies to both main girder and launching nose.
Convex : Convex curvature (center of circle located below)
Concave : Concave curvature (center of circle located above)
The ILM Wizard defines the bridge model as a 3-dimensional curved bridge if the radius is specified. Without the radius, it defines the bridge model as a straight 2-dimensional bridge.
Stage Duration
Specify the number of days it takes to assemble reinforcing steel and formwork, cast and cure concrete, and dismantle the formwork for one segment prior to launching. Note that the time that takes to launch the segment is implicitly included since its duration is minor in nature.
Segment Age
Specify the initial maturity of the segment concrete at the start of each construction stage. It represents the duration for concrete pour to curing prior to launching. The Stage Duration of subsequent stages is used to reflect the passage of time after launching. The Segment Age is used to calculate the time dependent material properties such as creep, shrinkage, modulus of elasticity, tendon stress loss, etc.
Launching Nose
Material, cross-sectional properties, and length of the launching nose are defined.
Material
Specify the Material number for material properties.
Section
Specify the Section number for section properties.
Click the
buttons to the right of Material and Section to create new or modify the existing materials and sections.
Length
Specify the length of the launching nose.
Tapered Section Group is automatically assigned to the launching nose during its generation. The Tapered (non-prismatic) section defined in Section is maintained even after the launching nose is divided into a number of elements by the launching distance.
Bridge Model
Define the material and section of the main girder and the composition of segments.
Material
Material of main girder
Section
Section of main girder
Only sections of the PSC-1CELL, 2CELL / PSC-3CELL / PSC-nCELL / PSC-nCELL2 types can be selected.
Click the buttons to the right of Material and Section to create new or modify the existing materials and sections.
Neutral axis is located at the centroid of the cross section.
Segment
Define the units of main girder fabrication corresponding to the individual construction stages.
In an ILM construction, a segment represents the length of girder fabricated in a construction stage at the on-site fabrication plant. One segment corresponds to one construction stage. The Wizard internally creates sub-stages required to launch the full length of each segment reflecting the one-time launching distance. Accordingly, the elements created by dividing the segments must be multiples of the one-time launching distance.
Length : Length of a segment
Repeat : Number of segments to be created repeatedly.
Click to add the segment input data to the list. The Boundary Condition to the right automatically lists the division points (nodes) of the segments to enable us to input boundary conditions at each launching step. Insert locations may be adjusted by the
and
buttons. Use
and
buttons to change or delete segments.
Boundary Condition
Define the boundary conditions to be applied to the construction stage analysis reflecting the on-site fabrication plant, temporary supports, and the piers and abutments of the completed (post-construction stage) structure. The boundary condition for the completed structure can be separately modified in the corresponding construction stage (post-construction stage).
If Final is selected, define the boundary condition representing the piers and abutments.
Distance
Referenced to the completed structure, Distance represents the distances from the start (left end - origin) abutment of the bridge to the individual nodes. The distances are automatically calculated and listed by the input data in Segment. Select the locations to which the boundary conditions are assigned (locations of piers and abutments for the completed structure) and click the after entering the following information:
Click the to delete the boundary condition of the selected location. Multiple selections are possible by the use of the [Ctrl] key.
Temporary Boundary Position
Temporary Boundary Position represents the temporary piers and supports for the launching nose and prefabrication plant. Note that the launching direction is from the right end abutment to the left end abutment (origin of the bridge). The Length for the No.1 position retains the absolute distance from the origin and represents the right end abutment, which is the right end of the completed bridge. The Length for the No.2 and beyond represents the incremental distances from the right end abutment to the temporary piers to the right.
Type
Select the type of boundary condition. The components of the degrees of freedom (dof) are defined in the global coordinate system (Node Local Axes if predefined).
None
No boundary condition applies.
Support
Check in the appropriate boxes to constrain the desired degrees of freedom.
Dx : dof in GCS X-axis (Node Local x-Axis)
Dy : dof in GCS Y-axis (Node Local y-Axis)
Dz : dof in GCS Y-axis (Node Local y-Axis)
Rx : Rotational dof about GCS X-axis (Node Local x-axis)
Ry : Rotational dof about GCS Y-axis (Node Local y-axis)
Rz : Rotational dof about GCS Z-axis (Node Local z-axis)
Point Spring
Define the elastic support stiffness conditions for each dof.
SDx : Elastic support stiffness in GCS X-axis (Node Local x-Axis)
SDy : Elastic support stiffness in GCS Y-axis (Node Local y-Axis)
SDz : Elastic support stiffness in GCS Z-axis (Node Local z-Axis)
SRx : Elastic support rotational stiffness about GCS X-axis (Node Local x-Axis)
SRy : Elastic support rotational stiffness about GCS Y-axis (Node Local y-Axis)
SRz : Elastic support rotational stiffness about GCS Z-axis (Node Local z-Axis)
Elastic Link
Elastic support rotational stiffness about GCS Z-axis (Node Local z-Axis)
Elastic Link Length
Enter the length of an elastic link element. It is used only to display the element on the screen and does not affect the analysis results.
Link Type
General Type
A general elastic link element is created. Enter the stiffness of the elastic link element in the local element axes (SDx, SDy, SDz, SRx, SRy & SRz).
Rigid Link
Infinitely stiff element condition is assigned. The degrees of freedom are slaved and as such no stiffness needs to be entered.
Tens.-Only
A tension-only elastic link element is created. The axial stiffness (SDx) of the elastic link element is entered. A sufficiently large value (1.0 x 1010 KN/m) may be entered.v
Comp.-Only
A compression-only elastic link element is created. The axial stiffness (SDx) of the elastic link element is entered. A sufficiently large value (1.0 x 1010 KN/m) may be entered.
Beta Angle : Enter "Beta angle" to define the local element coordinate system of the elastic link element.
Beta Angle
Enter "Beta Angle" to define the local element coordinate system of the elastic link element.
ILM Bridge Model Wizard automatically creates Element Group, Boundary Group and Load group to generate the model data. Refer to Define Structure Group, Define Boundary Group and Define Load Group.