Pot Bearing [SIG]
- Umut Nuhat Sevinc
- Melis Ceylan
The definitions made in this section affect the 3D model and, accordingly, the 2D model. The finite element model will be visible when fixity values are defined. The definitions related with 3D model of the object can be specified by using the tabs ‘Masonry’, ‘Pot and Piston’, ‘Sole Plate’.
Articulation
Insertion Point: Used for specifying the bearing location and can be selected by using the three dots and the options ‘Pick...’ and ‘Select...’.
Tx[Fixed/Free/Stiffness]:When the bearing rotation is 0 degrees, Tx represents the stiffness in the longitudinal direction. It is typical for a continuous girder to have at least one fixed bearing (or to use a real stiffness value) in the Tx direction.
Ty[Fixed/Free/Stiffness]: Ty represents the stiffness in the transverse direction when the bearing rotation is 0 degrees.
Tz[Fixed/Free/Stiffness]: Tz represents the stiffness in the vertical direction. It is common to use a high stiffness value, such as 1000 kip/in, or to fix the bearing.
Rx[Fixed/Free/Stiffness]: To address stability concerns, a small Rx stiffness can be used in the torsional direction (Rx) under certain conditions. If the constructed girders are not connected with bracings to other girders at any stage, it can result in stability issues. Therefore, a small Rx stiffness is recommended to overcome this problem.
Ry[Fixed/Free/Stiffness]: Typically, bearings are free to rotate in the Ry direction.
Rz[Fixed/Free/Stiffness]: Typically, bearings are free to rotate in the Rz direction.
Bearing Rotation: Curved decks can be guided either radially from a fixed point or tangentially to the radius of curvature. When the deck is guided radially, precise geometry is crucial for the bearings that are farthest from the fixed point. For structures with a constant curvature, it is recommended to align the bearings tangentially to effectively guide the deck around the curve as it expands and contracts.
Transfer Forces to Substructure [Yes/No]: If the user chooses to connect the superstructure to the substructure, a two-node spring is required between the pier cap and the girder, which can be generated by selecting “YES”. Conversely, if there is no substructure or if the abutments are being considered ( currently, abutments in OpenBrIM have the "Generate FEM" option set to “NO”), the correct setting for the "Transfer Forces to Substructure" parameter is“NO” and one node springs are needed.
Bearing Bottom Elevation (readonly): The bottom location of the bearings in 3D, with respect to the Z-axis of the Global Coordinate System, is displayed to the user in this column, regardless of the alignment's vertical definition.
Masonry
3D related definitions can be made by using related tabs of the object. Masonry Tab includes parameters below:
Width of the Masonry Plate: The width of the masonry plate in the transverse direction can be specified using this parameter.
Length of the Masonry Plate: The length of the masonry plate in the longitudinal direction can be specified using this parameter.
Thickness of the Masonry Plate: The thickness of the masonry plate in the Z direction can be specified using this parameter.
Edge Distance of Bolt Holes (Long. Dir.): For the bolts placed in both the masonry plate and the sole plate, the edge distance in the longitudinal direction can be specified using this parameter.
Edge Distance of Bolt Holes (Trans. Dir.): For the bolts placed in both the masonry plate and the sole plate, the edge distance in the transverse direction can be specified using this parameter.
Diameter of Bolt Holes: The diameter of the bolt holes can be specified using this parameter.
Show Bolt Hole (Detailing) [YES/NO]: To display the bolts, this parameter should be set to ‘YES,’ and the DETAILING button on the top middle bar must be turned on.
Number of Segments Used to Draw the Bolt Hole: A higher number of segments results in a smoother display of the bolts. If this parameter is set to 3, triangular shapes of the bolts will be visible. As the number increases, the bolt geometry will be generated to more closely resemble a circular shape.
Pot and Piston
Pot and Piston tab includes parameters below:
Piston Diameter: The diameter of the piston can be specified using this parameter. For visual representation, refer to the figure below.
Pot Wall Thickness: The thickness of the pot wall can be specified using this parameter. For visual representation, refer to the figure below.
Piston Thickness: The thickness of the piston can be specified using this parameter. For visual representation, refer to the figure below.
Elastomer Disc Depth: The depth of the elastomer disc can be specified using this parameter. For visual representation, refer to the figure below.
Bearing Depth of Piston Compression: The bearing depth for piston compression can be specified using this parameter. For visual representation, refer to the figure below.
Sole Plate
Sole Plate tab includes parameters below:
Sole Plate Length: The length of the sole plate in the longitudinal direction can be specified using this parameter. For visual representation, refer to the figure below.
Sole Plate Width: The width of the sole plate in the transverse direction can be specified using this parameter. For visual representation, refer to the figure below.
Thickness of the Sole Plate: The thickness of the sole plate in the Z direction can be specified using this parameter. For visual representation, refer to the figure below.
Capacity
Bearing Capacity: The bearing capacity can be adjusted using this parameter.