Safe Design

Design Preferences

Form: Design Preferences

Use the Design menu > Design Preferences command to access the Design Preferences form and set the design preferences for slab and beam objects.

Note: The Design Preferences form also displays when the Design Preferences Modify/Show button on the New Model Initialization form is clicked.

� Code tab. SAFE completes analysis and design in accordance with the code selected here. The program default is ACI 318-08. Select another code from the drop-down list if desired.

� Resistance Factors: Modify the default resistance factors as necessary by typing directly in the edit boxes. For American and Canadian codes, these are Phi factors, while for most other codes, these are typically Gamma values.

� Min. Cover Slabs tab. Modify the default top and bottom clear covers for the slab mild reinforcement, and the CGS at different locations for the slab post-tensioning tendons by typing directly in the edit boxes. SAFE applies the clear cover specified to the outer layer and assumes that the inner layer is located directly inside the outer layer for both top and bottom rebar. Layer B is the default inner layer, but this can be changed to Layer A by clicking on the drop-down list. Select the preferred bar size (non-prestressed) for slab reinforcing from the drop-down list. This cover will be used for all design strips unless a different value is specified for selected strips using the Design menu > Slab Design Overwrites command.

� Min. Cover Beams tab. Modify the top and bottom clear covers for beam mild reinforcement, and the CGS locations for the post-tensioning tendons by typing directly in the edit boxes. Select the preferred bar sizes (non-prestressed) for flexural and shear reinforcing from the drop-down lists. This cover will be used only on selected beams if the From Preferences option was chosen using the Design menu > Beam Design Overwrites command.

� P/T Stress Check tab. Modify the default concrete strength ratio at transfer; the initial, final, and sustained allowable tensile and compressive stress factors; and the fraction of sustained live load to be considered. The default values initially displayed are specific to the Design Code shown on the Code tab. A change to the Design Code will reinitialize the default values shown on the P/T Stress Check tab.

See Also

Punching Check Overwrites

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Design Combos

Form: Design Load Combinations Selection

Use the Design menu > Design Combos command to review and modify the load combinations to be used during design.

Note: It is not necessary to run the analysis or select an element before using the Design menu > Design Combos command.

Click the Design menu > Design Combos command to access the Design Load Combinations Selection form. On that form, review or modify data in the two following areas:

� Select Type Select the type of load combinations to be displayed in the List of Load Combinations list box in the Select Load Combination area. The choices are Strength (Ultimate), and if post-tensioning is present in the model, Service-Initial, Service-Normal, and Service-Long Term.

� Select Load Combination The default design load combinations created by SAFE are listed in the Design Load Combinations list box. The number and type of default combinations depends on the Load Cases previously defined and on the design code specified using the Design menu > Design Preferences command. SAFE uses the design load combinations listed in the Design Load Combinations list box during design. Thus, if necessary, review or modify the list of Design Load Combinations using the buttons on the form:

� Highlight a Combination and use the Show button to display the Load Combination Data form, which shows the definition of the design load combination. This form is for display purposes only; no changes can be made here.

� Highlight a Combination and use the Add and Remove buttons to move load combinations into and out of the Design Load Combinations list box. Use the Ctrl and Shift keys to make multiple selections before using the Add and Remove buttons.

Note: The design load combinations also can be accessed by right clicking Load Combinations under the Load Definitions sub-node on the Model Explorer window.

Slab Design Overwrites

Use the Design menu > Slab Design Overwrites command to overwrite design parameters for a selected design strip(s) or slab object(s). A sub-menu consisting of Strip Based or Finite Element Based will display. If only one of these sub-commands



is available, only design strips (Strip Based) or slab objects (Finite Element Based) have been selected.

The Design menu > Slab Design Overwrites > Strip Based command will access the Strip Based Slab Design Overwrites form.

The Design menu > Slab Design Overwrites > Finite Element Based command will access the Finite Element Based Slab Design Overwrites form.

Note: Design strip information can be accessed by expanding the Design Strip Objects sub-node on the Objects node on the Model tab of the Model Explorer window.

Beam Design Overwrites

Form: Beam Design Overwrites

Use the Design menu > Beam Design Overwrites command to overwrite beam design parameters for a selected beam object.

Select one or more beam objects and click the Design menu > Beam Design Overwrites command to access the Beam Design Overwrites form. On that form, select and enter data in the following two categories:

� Cover Select from one of the three following options to set the concrete cover for the beam reinforcing steel:

� From Section: Select this option if the cover should be as shown on the Beam Property Data form. This is the default setting.

� From Preferences: Select this option if the cover should be as set in the Design menu > Design Preferences command.

� Specified to Center of Steel: Select this option to explicitly locate the rebar by specifying the distance to the center of steel in the edit boxes.

� Live Load Reduction Specify a factor to reduce the live load forces used in beam design. Most codes allow for live loads to be reduced based on tributary area calculations. The resultant forces in the selected beam objects will be multiplied by the Reduced Live Load Factor when used for design. The only forces affected will be those that result from load cases associated with load patterns with a type of REDUCIBLE LIVE, or load cases that have been user identified as REDUCIBLE LIVE using the Design button on the Load Case Data form.



The default value for the Reduced Live Load Factor is 1, which means that there is no reduction; a value of 0.75 would mean that the forces are decreased by 25%.

� Design option. To ignore post-tensioning during design, check the Ignore PT When Designing This Beam check box.

Note: Beam information can be accessed by expanding the tree under Objects > Line Objects on the Model tab in the Model Explorer window.

Punching Check Overwrites

Form: Punching Shear Design Overwrite, Punching Shear Specified Perimeter, Punching Shear User Specified Support/Load Size, Punching Shear Specified Openings

Use the Design menu > Punching Check Overwrites command to overwrite punching shear design parameters for a selected point object. This point may be at column, support, or load locations.

Select one or more point objects in the model datum plane and click the Design menu > Punching Check Overwrites command to access the Punching Shear Design Overwrites form.

� Check Punching Shear: When Program Determined is selected, punching shear will be checked. If No is selected, the options listed below will not be available.

� Location Type (SeeTooltip): Choose Auto from the drop-down list if the program is to determine the column location, otherwise choose Interior, Edge or Corner. Location affects the calculation of the allowable punching shear. A sketch illustrating the placement of the edges and corners will display by "hovering" the mouse cursor over the words Location Type.

� Perimeter drop-down list

� Auto. Select this option to have the program determine the perimeter distance used in the punching shear calculation.

� Specified Perimeter. Select this option and click the Specify button to input the perimeter coordinates using the Punching Shear Specified Perimeter form. If a segment is null (a line drawn and assigned the None property), it is not used in the perimeter calculation (e.g., at a slab edge).

� Specified Support/Load Size. Select this option and click the Specify button to input the support or load in the X and Y directions using the



Punching Shear User Specified Support/Load Size form. The program automatically determines the punching shear perimeter from the values specified. Use the Counterclockwise Angle from the Global X Axis to Support/Load X Axis edit box to specify in degrees

� Use Effective Depth drop-down list.

� Auto. Select this option to have the program determine the effective slab depth of the punching shear perimeter.

� Specified. Select this option and then specify the effective slab depth of the punching shear perimeter in the Use Effective Depth Value edit box.

� Openings drop-down list.

� Auto. Select this option to have the program determine if there are openings in the punching shear region.

� Specified. Select this option and click the Specify button to input the geometry for either rectangular or circular openings on the Punching Shear Specified Openings form. On that form, click in the Opening Shape column in the Opening Data area to select Rectangle or Circle from the drop-down list, and then input location and size values in the other column edit boxes. Add additional openings in the same manner. These openings are used only in the punching shear calculations; they do not appear in the model.

� Reinforcement Allowed: Select No, Rebar Ties, or Stud Rails from the drop-down list depending on the type of reinforcement allowed. If No is selected, reinforcement spacing does not apply. If Stud Rails is selected, the reinforcement spacing is the spacing of the studs. If Rebar Ties is selected, the reinforcement spacing is the spacing of the single leg stirrups.

� Reinforcement Pattern: If reinforcement is allowed, select Orthogonal or Radial from the drop-down list to specify the reinforcement pattern.

� Reinforcement Fy: If reinforcement is allowed, specify the yield strength in the edit box.

� Reinforcement Diameter: If reinforcement is allowed, specify the diameter in the edit box.

� Reinforcement Spacing: If reinforcement is allowed, specify the spacing in the edit box.

Note: Point information can be accessed by expanding the Point Objects sub-node



under the Objects node on the Model tab of the Model Explorer window.



Safe Design

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