Grillage Model Wizard (Layout)

The wizard automatically generates grillage model with the longitudinal members coincident with longitudinal webs for multicellular bridge decks. Define the road alignment information, the span information, and the boundary conditions etc in the Layout tab.

From the Main Menu select Structure > Wizard > Grillage Model Wizard > Layout

Bridge Material

Select the Material property of the bridge. The material should be defined in advance. Click to define a new material.  

 Span Information

Specify the spans sequentially. Example - 300, 400, 2@300, 100  

 Skew Angle

Skew angle of the bridge in plan (θ deg)

 (+) indicates counter-clockwise direction.

Click   to enter different skew angles by spans.

Offset

Distance between the reference line and the center line of the bridge

 Alignment of Transverse Members

Transverse members may be orthogonal or skewed with respect to the longitudinal members.

Perpendicular                                      Skewed

Radius

Specify the radius in the case of a horizontally curved bridge.

Convex: Convex curvature (center of circle located below)

Concave: Concave curvature (center of circle located above)

Multi-Curve: Click  to input multi-curves  

The curvature can be defined as the combination of a straight line and a curve.

Boundary

• Integral Type

In case of the integral bridge, enter data for the substructure as follows.

Abutment Section

Abutment Height

Pier Section

Pier Height

Bottom of Abutment / Pier: Boundary conditions of substructure

Fixed: Set as a fixed support.

Spring Support: Set as a spring support. Specify the horizontal and vertical spring stiffness. Click if spring stiffness is different for each support.

• Bearing Type

When superstructure and substructure are connected with bearings:

Supports: Bearings are represented by fixed / free support. Once the position of fixed support is determined, all the other supports are considered as free support longitudinally.

Elastic Link: Bearings are represented by Elastic Link. Enter the stiffness of bearings by directions for the abutments and the piers. Click to enter different stiffness for different supports.

Fixed Support: Select longitudinally fixed support. Longitudinally and transversely fixed bearing is used as a reference point for the determination of the direction of free bearings in the In Line with Fixed Support option.

Direction: Choose the method of determining direction of the free bearings.

Tangential: The restraint-free direction is tangent to the longitudinal axis of the bridge. (i.e. tangent to the curvature of a curved bridge or in the direction of a straight bridge)

In line with Fixed Support: The restraints are freed in the directions from the individual supports to the fixed support.

Tangential                                                 in Line with Fixed Support

• Hybrid Type

When the piers are integral with the deck structure but the abutments are not integral with the deck structure:

Abut: Bearing

Supports: Bearings are represented by fixed / free support. Support conditions are automatically considered as shown below. Longitudinal movement for the start abutment is fixed. All the other supports are considered as free support both longitudinally and transversely.

Elastic Link: Bearings are represented by Elastic Link. Enter the stiffness of bearings by directions for the abutments. Click to enter different stiffness for different abutments.

 Pier: Integral

Pier Section

Pier Height

Bottom of Pier: Boundary conditions of piers

Fixed: Set as a fixed support.

Spring Support: Set as a spring support. Specify the horizontal and vertical spring stiffness. Click if spring stiffness is different for each pier.

Open...

Open the data saved as in the *.wzd file type in the Grillage Model Wizard. By using this function, we can re-execute midas Civil and subsequently check and modify the previously entered data within the Wizard.

Save As...

Save the data entered in the Grillage Model Wizard as the *.wzd file type.