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Grillage Model Created Edited

Grillage Model Wizard - Span


Define support position, bent-cap width, transverse member spacing, and cross-sections for each span.



From the main menu, select [Structure] tab > [PSC Bridge] group > [PSC Box Bridge] > [Grillage Model]



Structure-Wizard-Grillage Model-Span.png

Grillage Model Span dialog box


Span1/Span2/Span3 ... tab

The number of tabs is determined by Span Information settings on the Layout tab.


Span Length

Determined by Span Information settings on the Layout tab.



Outer Span (B) / Inner Span / Outer Span (E)


Db2 / Db1 / De1 / De2

Refer to the figure to set the support position, bent-cap width, etc.


Transverse Member Spacing

The default spacing is 0.1×LS. LS = span length – Db1– De1


Section Assignment... 

Assign the cross-section along the longitudinal axis.

Structure-Wizard-Grillage Model-Section-section assignment.png


Reference position to assign a section along the longitudinal axis.


Distance from the Reference position along the longitudinal axis.


Select the cross-sections for each location. Once different sections are assigned to two different positions along the longitudinal direction, tapered section is automatically generated between the two positions.

Connection of elements in the longitudinal direction

when the centroids of the section entered is not coincided with that of the main section in any of the vertical and horizontal directions, Section Offset is used to  adjust the difference. As a result, the axis of the elements in the longitudinal direction is laid in parallel to the geometric line of the road in the X-Y plane. The centroids of the sections were indicated in below Figure to facilitate understanding. In a real model, it applies to elements in the longitudinal direction that are divided with respect to the web or slab. In addition, sections created in Grillage Model Wizard are aligned at center-top. Therefore, below Figure will have a longer section offset by which is indicated in red.



Prismatic Section

pply the same cross-section to the whole bridge. The applicable type of section is PSC-nCell, PSC-nCell2, and PSC-Value.


Copy the Current Span Data to Other Spans...  

Apply the same data to other spans.


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