RAM Foundation Tutorial

This section illustrates the analysis and design of the spread footings and continuous foundations in an integrated model. This section can only be completed if you have licensed and installed the RAM Foundation module. You may begin with the model that you generated in the previous portions of this tutorial, or you may open the model called RAMTutorial_v14_US.rss from the RAM Manager.

RAM Foundation Basics

To invoke RAM Foundation from the RAM Manager:

Because RAM Foundation is integrated into the RAM Structural System, it uses the same model and database as RAM Frame and RAM Steel when designing foundations. In order for the program to design the foundations, the loads must be determined by running the gravity column design and/or lateral analysis in RAM Frame. If this has not been done, do so now, then proceed with this Tutorial. While most of the information needed for foundation design is taken from the database, some data does need to be entered in the Foundation program itself.

Before foundations can be designed, the following must be defined:

Once this is complete, a design can be performed, but we recommend that you review the design and optimization criteria closely first.

To establish the source for the design loads:

Leave the Forces on Gravity Members criteria set to use the third option: RAM Steel for steel members and RAM Concrete for concrete members.

Since this model has 2 way decks RAM Steel cannot account for the loads on members underneath those decks. This is why the first option is grayed out.

To set the design criteria:

These parameters have a significant effect on the way the foundations are designed. For a complete description of the option see the RAM Foundation manual. For this example:

Under Design Method:

Select Design footings based on applied forces (rather than soil capacity)

sub-option = Select optimum footing design for each column.

Under Design Method:

Optimization Criteria

There are additional criteria that affect the design of the foundations. To set those options now:

Assign Soil Capacity

To assign soil capacity to this model

Initially, only the Allowable Bearing Capacity option for entering the soil capacity is available. This option allows the engineer to idealize the soil capacity by using just one value to represent the soil capacity regardless of dimensions of the foundation or depth of the soil.

You can also create a soil table by using the wizard. This feature allows you to assign the modulus of subgrade reaction that affects the springs that will be used in the analysis of the footing.

To assign an Allowable Bearing Capacity:

NOTE: All of the Assign commands in RAM Foundation give the option of Single, Fence or All for making assignments. [Single] will change the cursor to the target and allow for assignments on a foundation - by - foundation basis. [Fence] will change the cursor to a rubber band. Assignments are made to foundations completely enclosed within the rubber band. [All] assigns the value to all foundations within the model. If a new foundation is added to the model it must also have a soil assignment made.

Assign Base Plate Sizes to Lateral Columns

The Assign – Base Plate Size command allows the engineer to assign different base plate sizes to different columns on a continuous foundation.

In our example the columns are mostly concrete columns with a specified size. For the gravity steel columns, base plates are already provided by the RAM Steel Column design. These sizes can be overridden with the Assign – Base Plate Size command. This size will only be used in RAM Foundation. It will NOT be exported back to RAM Steel Column Design. Additionally, once an override is made in the foundation module, this size will continue to be used by RAM Foundation even if the size is changed in RAM Steel Column Design. To update a base plate so that that the optimum base plate size is again obtained from the RAM Steel Column Design module, the “Clear User Defined Base Plate Size” option must be selected and assigned.  Upon re-running the RAM Steel Column Design, the new optimized base plate size will automatically be assigned.

Assign Geometry

The footing module allows you to assign any of the footing dimensions that you do not wish to have optimized. For spread footings, all of the dimensions may be optimized. Continuous footing design requires you to assign at least the width.

To assign the geometry of the spread foundations:

NOTE: The footing need not be centered under the column. Any of the length dimensions may be set or limited and the eccentricity will be considered in the design.

To assign the geometry of the continuous foundations:

Assign Surcharge

Since the footing is typically underground, you can assign a surcharge load to be considered in the design. The surcharge will affect the soil check and the possibility of uplift, but does not enter into the design calculations for the foundation itself. The self weight of the foundation is automatically accounted for by the program.

To assign a surcharge:

Assign Pile Geometry

In order for the program to check the pile design, you must provide the unfactored capacity of the piles and the layout which should be used.

To assign the pile cap geometry:

Load Combinations

Before any foundations can be defined, you must specify the load combinations to consider. These may be created manually as User Defined Load Combinations or Code Generated Combinations can be utilized..

The Load Combinations box should be filled with load combinations and each should be checked to Use.

Design All and View/Update

The foundations should now appear yellow indicating that the foundations are all ready to be designed (with the exception of the mat foundation which can only be designed using RAM Concept). To design the foundations:

The program will calculate the optimum sizes for all of the footings. When finished, each should be drawn in green and sized appropriately. Any foundations that appear in red could not be successfully designed.

This may take a few minutes to complete. Keep in mind that the program is running an individual finite element analysis of each continuous foundation considering compression-only springs representing the soil below. The progress is indicated in the status bar in the lower left hand corner of the screen. For a complete explanation of how foundations are designed by the program refer to the RAM Foundation manual.

To investigate the design of individual spread footing:

With the target cursor, select the spread footing at Grid B - 2.

The dialog box will open to the Results Tab provided a successful design was accomplished. From here you can see the size of the footing and the reinforcement required. The signal light indicating the status of the design is shown. From here you can change the sizes or the reinforcement, redesign the footing and update the model if desired.

NOTE: The orientation of the foundation in the view/update dialog box is adjusted to so that the footing length points to the right. This may not match the orientation on the plan.

The foundation will now appear blue since it is user assigned. Note that the arrow should still appear green. This indicates that the design is still satisfactory. If something should change later causing the foundation to fail, the arrow will change to red.

To investigate the design of individual continuous foundations:

The dialog box will open to the Results Tab provided a successful design was accomplished. From here you can see the size of the footing and the reinforcement required. The signal light indicated the status of the design as shown. In this case you have optimized for the length of the footing beyond the last column as well as the thickness. Furthermore, the top and bottom reinforcement has been selected. The reinforcement box shows what reinforcing bars have been selected. It defaults to the Longitudinal Top bars.

To change the selection:

Take a moment to become familiar with the contents of the other two Tabs: Design and Material Properties.

To investigate the design of individual continuous foundations:

As with the other foundations, the pile cap thickness or rebar may be altered through the view/update command.


Many different reports can be generated from the Foundation Module. The printed output is mostly generated using the Reports menu.

To print the service loads for a foundation design:

Click the same continuous footing along Grid A. The Foundations Load report should appear. Notice that the various elements that are supported by the foundation are listed separately. For an explanation of sign convention see the Foundation manual.

To print a summary of the spread footing designs:

For a continuous foundation design report:

The foundation envelope report is also available from the reports menu. This report lists the maximum design forces and soil stresses along the length of the foundation. This is the same report that you see when you select [View Envelope] from the View/Update dialog box.

Take time now to review the various reports available in the Reports menu.

Thank you for taking time to complete this RAM Structural System Tutorial. Refer to the various program manuals for additional information on any aspect of the program that you do not fully understand.