RAM Concrete Shear Wall Tutorial

To design all your concrete Shear Walls you need to be in the Concrete Shear Wall Design Mode. To switch to the concrete column mode:

• Select Mode – Concrete Shear Wall.

Before you can enter the concrete Shear Wall design mode the RAM Frame analysis should have been performed.

The mode drop-down on the toolbar will indicate you are in Shear Wall design mode.

Concrete Shear Wall Criteria

The criteria by which concrete shear walls are designed is dependent on the design code selected. For this example, select the ACI 318-08 (BS8110:1997) design code.

• Select Criteria – Code…
• Choose ACI 318-08 and click [OK]

Review the Design Code Parameters:

For the purposes of this tutorial, copy these settings:

Wall Design Groups

In the Concrete Shear Wall program, walls are grouped for design into “Wall Design Groups”. A Wall Design Group can consist of a single wall or multiple walls. To assign Wall Design groups, do the following:

• Select Assign - Wall Design Groups…

• Click [Add - Single]
• Click on the bottom L shaped walls in both stacks (4 walls total).

Right click the mouse to return to the Assign Wall Design Groups dialog.

Note that the Wall Design Group number is update to 2, indicating that the next assignment will default to Wall Design Group number 2. The “new” in parentheses denotes that no walls are currently assigned to Wall Design Group 2.

• Click [Single]
• Click the target cursor on the remaining walls that comprise the elevator shaft boundaries.
• Right click to return to the dialog.
• Click [Fence]
• Fence the remaining 2 walls of the model.

Now all of the walls in the model belong to a wall design group.

You can also assign a wall panel priority to any wall panel which will force the program to design that wall panel first. To assign a Wall Panel Priority:

• Select Assign-Wall Panel Priority
• For Priority Enter 1.

NOTE: This is an arbitrary number, but the higher number will get the higher priority. All walls have Priority zero unless otherwise assigned.

• Click [Single].
• Select the two walls in Wall Group 1 between grids B and C.

Wall Panels with an assigned priority.

Assign Section Cuts

There are two ways to assign section cuts to a wall design group: automatic generation or manual assignment.

We’ll start with automatically generating section cuts.

• Select Assign– Section Cuts – Add Automatic…

The Assign Autogenerated Section Cuts dialog will open with the following defaults. Note that the “Max Cut Spacing” of 0.0 results in the greatest possible spacing between cuts.

• Click [Single]
• Click the target cursor Wall Design Group 1. Notice how the section cuts are generated around the wall opening per the selected criteria.
• Right click to return to the dialog
• Click [Single]
• Click the target cursor on Wall Design Group 2.

Now we will manually add section cuts to Wall Design Group 3. To assign section cuts manually, you must be in elevation view. You can select elevation view before issuing the add command or, if you issue the command first, you will be prompted to do so.

• Select the Elevation View toolbar button

• Click the target cursor on the wall in Wall Design Group 3.
• Select Assign – Section Cuts – Add Manual…

Before the dialog opens, you must draw a line through your wall using the mini-target cursor at the approximate location of where you want your section cut.

When you release the mouse, the Add Section Cut dialog will open.

• Adjust the value in the Offset Distance edit box to 100.00 inches (2550 mm).
• Click [OK].
• Add another to the upper wall at 10 inches.

If there were multiple walls in this wall design group, checking the “Include All Wall in Wall Design Group” would result in the section cut being assigned to all walls, even if they are out of plane of the originally selected wall.

• Click the 3D View toolbar button to return to 3D View.

Create and Assign Bar Pattern Templates

During the design process, reinforcement is selected for the walls based on the Bar Pattern Template assigned to the Wall Design Group. This is similar to the bar groups in the concrete column program.

You can access the “Edit Bar Pattern Template” dialog to create bar pattern templates either from the menu or from the Assign Bar Pattern Template dialog. For this example, we will access it through the assign dialog.

• Select Assign - Bar Pattern Templates…

• Click [Edit Templates] at the bottom of the dialog.

• Check the Automatically Generate box beside the label
• For the SI Model use the defaults.
• Enter 2 for the Number of Curtains
• For Horizontal Bars select:
  • Minimum Bar Size = #5
  • Maximum Bar Size = #14
  • Maximum Spacing = 12 in
  • Minimum Spacing = 4 in
  • Spacing increment = 4 in
• For Vertical Bars select:
  • Minimum Bar Size = #6
  • Maximum Bar Size = #18
  • Maximum Spacing = 12 in
  • Minimum Spacing = 4 in
  • Spacing increment = 4 in
• Click [Add].
• Click [OK] to return to the Assign Bar Pattern dialog.

• Select the newly created bar pattern template in the list box.

  Notice that the information about that template is shown on the right.

• Click [All] to assign this bar pattern template to all of the wall design groups in the model.

Manual Reinforcement and Special Boundary Elements

In accordance with the design requirements of many design codes, Special boundaries can be assigned to a wall or walls through the manual reinforcing command.

• Select Assign-Manual Reinforcement.
• Use the target cursor to select left most wall of Wall Group 1.

• When the Manual reinforcement dialog comes up add 3 new reinforcing zones.
• Use your cursor in the graphics portion of the dialog to move the boundaries as displayed. Change the 2nd zone boundary to No, but Check.
• Click [OK].
• Repeat for the adjoining wall but move the boundaries to the wall edges.

Generate Load Combinations for Design

The design of concrete shear wall is based on combinations of loads rather than individual loads. Use the load combination generator to create the code specified load combinations.

• Select Combinations - Generated….

• Select IBC2006 (BS 8110 1997) in the Code for Combinations dropdown.
• Enter 1.113 for Sds
• Use reduced factor for snow.
• Click [Generate]
• Click [OK]

Load combinations can be turned on and off for consideration in the design. The more load combinations that are turned “on”, the longer a design will take.

Design Wall Design Group 1

• Select Process - View/Update…
  
• Select Wall Design Group 1

When the View/Update dialog opens, use the target cursor to select a section cut for which results will be displayed. The selected section cut will be highlighted in orange. At the top of the wall is a group of buttons that allow you to zoom and alter the keyboard and mouse functions. Familiarize yourself with these buttons. In the bottom portion of the screen you will notice the manual reinforcement you entered earlier displayed graphically.

Review Axial-Flexural Design Results:

• Select Axial/Flexural from the back row of tabs. This is the default and most likely already selected.
• Select Results from the front row of tabs.

The axial-flexural design results for the selected Section Cut are displayed in tabular form in the screen to the right. Each row in the spreadsheet corresponds to a load combination.  Above the spreadsheet is a summary of the design, including information on the controlling load combination.

• Select a load combination in the spreadsheet by clicking on it.

The locally (M_umaj, M_umin) and globally (M_uxx, M_uyy) oriented required moments for the selected load combination is then displayed below the spreadsheet.

• Once the Section cut has been selected and a load combo chosen, you can view the wall stresses from RAM Frame.
• At the bottom of the graphics screen select the show/hide mesh button. Then click the next one called mesh options.
  
• Notice that the wall now has a stress contour.
• In the mesh options menu you will see several stress types to select from. Take this opportunity to switch between them and see the behavior of the program. The stresses correspond to the load combos at a section cut, so changing the section cut and combo will yield different results.
  
• Select Interaction Surface from the front row of tabs.

The axial verses flexural plot that is shown corresponds to the angle resulting from M_umaj and M_umin for the selected load combination, referred to as the β angle.

Review Shear Design Results:

• Select Shear from row of tabs.

Review the boundary Element Design Results:

• Select Boundary Elements from row of tabs.

• Select the Tie/Link Design tab for information about the Tie design.
• Further information on boundary element design can be found in the shear wall manual.

Modifying the Design

Design wall group 3 in a similar fashion to Wall Group 1 by using the View/Update command. Notice that only the 2 user assigned section cuts are available for display.

• Select the elevation view button in the toolbar above the 3D view window.

• Select a wall in the Wall Design Group to indicate the elevation view to display. Note that, just as in the main program, the zoom, pan and rotate commands can be used to adjust the view on the screen. See the Concrete Shear Wall manual for more details.
• From the mouse tool bar button, select Mouse Selects Section Cut

• Select horizontal section cut SC3H:2

• Display the wall stresses for the controlling load combo, or display the reinforcing for the walls using the reinforcing button next to the show/hide mesh button.
• Select the Reinforcing tab.
• Change to Reinforcing select mode by using the drop down menu shown in the figure below.

• Select any of the vertical reinforcing bars in the upper wall section. It will be highlighted in light gray and the bar will be selected in the table on the right.

• Change the bar size to #11.

Note that the Section Cuts for the Wall Panel to which the bar belongs have turned yellow, indicating that the design is not current and needs to be run again.

• Make the same change in bar size to the next four cells directly below.

NOTE: When a new cell is selected, the bar is highlighted in the 3D view window.

• Click [Analyze]

Review the Design Results

• Select the 3D View button from the toolbar.

• Select Mouse Selects Section Cut
• Select horizontal section cut SC3H:2
• Click [View Summary] to review the design report. (Additional reports are available from the Reports menu).
• Click [Close] to exit View/Update

This completes the Tutorial for RAM Concrete. Proceed to the next section in order to work the RAM Foundation Tutorial.

• Continue to RAM Foundation Tutorial
• Go back to RAM Concrete Column Tutorial
• Up to the RAM Structural System Tutorial