2 - Multi-Segmental Wall

In this tutorial, a Multi-Segmental wall is designed in RSWall using the AASHTO 2020 standard. A step-by-step design process is provided.

Topics Covered:

• Multi-Segment Wall Design
• Manufacturer Library
• Wall Wizard
• Overall Slide2 Stability Analysis

Finished Product:

The finished product of this tutorial can be found in the Tutorial 2 folder. All tutorial files installed with RSWall can be accessed by selecting File > Recent Folders > Tutorials Folder from the RSWall main menu.

1.0 Getting Started

1. Open the RSWall program.
2. Select an empty project from the wall template options.
   
3. Click OK.

2.0 Project Settings

1. Go the Home ribbon and select Home > Project > Project Settings
   
2. In the Units tab, confirm that the Units are set to Metric, stress as kPa.
3. Select the Wall type tab. Confirm that Wall type is set to Segmental wall.
   
4. Select the Design Standard tab.
1. Confirm that the design standard is set to AASHTO (2020), and that Strength and Serviceability are toggled on under the Load Combinations options.



2. Select the FHWA tab, and tick the checkbox for Use FHWA method when computing seismic inertial force.
   
3. Select the Advanced tab.
4. Select the Ignore weight of wall facing during sliding calculations checkbox.
5. Select the Use average depth of adjacent reinforcement layers when calculating Tmax checkbox.
   
   
5. Select the Failure modes tab.
1. Select the Internal stability settings tab and deselect Crest toppling.
   
2. Select the Reinforcement strength settings tab and deselect Connection strength.
   
6. Select the Methodology tab. Select the following:
1. Active pressure method = Generalized wedge method.
2. Tension in reinforcement = Coherent gravity method.



7. Click OK to apply the changes and close the dialog.

3.0 Wall Units

In this section, we define the wall units of the model.

1. Go to the Wall ribbon.
2. Select Wall > Wall Profile > Define Wall Units
3. In the Define Wall Units dialog, add a new wall unit using the +Add button.
4. Add a Manufacturer Library to both Wall unit 1 and Wall unit 2 as shown below:
1. Click on the button next to Manufacturer Library.
2. Set Manufacturer = RediRock for both wall units.
3. For Wall Unit 1, under Blocks, select 28 in (710 mm) solid – R28T.
4. For Wall Unit 2, under Blocks, select 60 in (1520 mm) solid – R60M.





5. Click OK to close the Define Wall Units dialog.
6. Select Wall > Multi-Segment Wall > Wizard
7. In the Wall Wizard dialog:
1. Select the Import button.
2. Import PlanElevationPoints.txt from the tutorial folder.
3. Click OK in the Import CSV File dialog.



8. Click Next in the Wall Wizard dialog.
   
9. Click Next again. The last window shows the Wall Front view and Plan view of the selected segment.
   
   
   In this dialog you can make changes to each segment by adding and removing courses to the top and bottom of the segments or to the left and right of the segments. Also, other options such as splitting and merging segments are available.
   The segment heights are always equal to the highest elevation of the soil profile behind that segment.
10. Click Finish. You will see that multiple segments are created.
    

To edit segment coordinates, you can always:

• Select Wall > Multi-Segment Wall > Edit .
  

4.0 Section Profile

In this section, we will cover defining the wall section profile.

1. Select Wall > Wall Profile > Define Section Profile in the toolbar. Assign the following wall courses and Wall units (using the Assign uniform wall units to all layers option) to the segment profiles:
• Segment 1 Profile: 6 wall courses and Wall unit 1
• Segment 2 Profile: 7 wall courses and Wall unit 1
• Segment 3 Profile: 7 wall courses and Wall unit 1
• Segment 4 Profile: 8 wall courses and Wall unit 2
2. Click OK to apply the changes and close the Define Section Profiles dialog.
3. Click on a segment from the Segment Tree, then select Wall > Base > Define Base Strength
   
1. Set Contact with soil = Soil on soil.
2. Set Apply base strength to = All segments in current wall (Wall 1)



4. Click OK to close the dialog.

5.0 Soil

In this step we define the soil properties, and we assign them to different regions.

1. Go to the Soil ribbon.
2. Select Soil > Soil Geometry > Backslope Topography
   
3. In the Backslope Topography dialog, set the Terrain Profile = User defined.
1. Add 4 rows to the table and enter the following coordinates:
• X: 2, Y: 1
• X: 3, Y: 1
• X: 4, Y: 2
• X:5, Y: 2



4. Click OK and close the Backslope Topography dialog.
5. Select Soil > Soil Geometry > Front Face Topography
   
6. In the front Face Topography dialog, enter:
   1. Terrain profile = Infinite
   2. Embedment depth (m) = 0.4 m
7. Click OK to close the dialog.
8. Select Soil > Soil Conditions > Define Soil Properties
9. In the Define Soil Properties dialog, define soil properties according to the following table:

Soil Name/Property	Unit Weight (kN/m3)	Friction Angle (o)	Soil-Structure friction Angle (o)	Long-term cohesion (psf)
Retained	20	30	20	8
Reinforced	22	34	26.5	0
Foundation	23	34	20	0

AASHTO Standard does not typically allow consideration of cohesion in the backfill soils, as it is non-conservative. Typically, cohesion should only be considered if it is expected to be permanent with respect to the life of the structure. We are considering here for the purpose of providing an example.
10. Click OK to close the Define Soil Properties dialog.
11. Select Soil > Soil Conditions > Assign Soil Properties
    
12. In the Assign Soil Properties to Soil Regions dialog, assign the properties as follows by selecting a soil property and then clicking on a desired soil region:
1. Reinforced Soil: Reinforced soil property
2. Backfill Soil: Retained soil property
3. Leveling Pad: Retained soil property
4. Front Face Soil: Retained soil property
5. Foundation Soil: Foundation soil property



The reinforced soil region is defined. However, until you add your reinforcement layers you won’t be able to see the reinforced region.
The assign Soil properties dialog shows Leveling Pad and Front Face Soil. Unless you define them in the model, they won’t affect the results.
13. Click OK to close the dialog.
14. Select Soil > Groundwater > Define Groundwater
15. In the Define Groundwater dialog:
1. Select Include water table to enable the water parameters.
2. Under Water Profile, select Constant and set the Water elevation (m) = -0.457.



16. Click OK apply your changes and close the dialog.

6.0 Loading and Support

In the Loading and Support ribbon, we will define a live load and our reinforcement properties and arrangement.

1. Go to the Loading and Support ribbon.
2. Select Loading and Support > Loads > Manage Loads
   
3. In the Manage Loads dialog, define 3 Line Loads as follows:

Name/Load	Distribution	Horizontal distance (m)	Magnitude (kN/m)	Bearing width	Assigned segments
Load 1	Line Load	2.5	50	1	Segment 1
Load 2	Line Load	2.5	75	1	Segment 2, Segment 3
Load 3	Line Load	2.5	100	1	Segment 4







4. Click OK to close the dialog.
5. Select Loading and Support > Reinforcement > Define Properties
6. In the Define Reinforcement Properties dialog, define a property with the values provided in the tables below:
   • Tensile tab:

   Name/Property	Type	Coverage ratio (%)	Allowable tensile strength (static) (kN/m)
   Strip 1	Metallic strip	30	600

   
   • Soil Interaction tab:

Name/Property	Interface sliding friction angle (o)	Pullout method	Friction factor function type	Friction factor	Alpha coefficient
Strip 1	22	Friction factor	Constant	2	1



7. For the Connection and Design standard tabs, leave the settings as they are. Click OK to close the Define Reinforcement Properties dialog.
8. Click on a segment from the Segment Tree, then select Loading and Support > Reinforcement > Add Layout in the toolbar.
9. In the Add Reinforcement Layout dialog:
1. Select the Apply uniform reinforcements checkbox.
2. Set Length (m) = 5.
3. Then, select the Apply uniform placement checkbox.
4. Set Number of courses below first layer = 0 and Number of courses between layers = 1.
5. Set the Number of layers = 9.
6. Ensure reinforcement layout matches the table below, then click OK.

7.0 Results

1. Go to the Results ribbon.
2. Select Results > Compute > Compute to run the analysis.

Once computed, the results will resemble the following image for segments 1 and 4:

3. In the Segment Tree, there is a warning icon beside all the segments. This means that the Analysis Issues dialog should be reviewed. Select Results > Compute > Analysis Issues to open the dialog.
   
   This is just a general warning and does not indicate that anything is wrong with the model. Close the dialog.
4. Select Results > Compute > Report Generator to render a report. The Report Generator in RSWall provides all the hand calculations for the output results of the RSWall program.
5. Once the report is ready, click on the Results section under Navigation.
6. In the Results section, a List of symbols used in the analysis is provided. For each of the 4 segments modelled in this example, there are detailed hand calculations provided under their respective sections in the report.
   
7. Close the Report Generator.

8.0 Slide2 Overall Stability Analysis

This section will guide you through exporting the RSWall project to Slide2 and conducting an overall stability analysis.

1. Select Results > Export > Export to Slide2
   
2. In the Export to Slide2 dialog, select the All Segments checkbox and click Open in Slide2.
3. The model will open in Slide2.
   
   Multi-Segment walls will be imported into the Slide2 software as a Multi Scenario model (Master Scenario is the same as the first Scenario).
   After saving the file, you will see a warning regarding connecting water tables from the RSWall model to form a singular water table in Slide2.
4. Select File > Save As and save the Slide2 file as Tutorial2 Multi Segment Wall.
5. Ensure the model’s slope limits are in the same locations as the image below. To modify the location of a slope limit, right click on a slope limit and select Move Limits. Then drag the limits to the desired location on the model.
   
   
   RSWall models imported into Slide2 will run with the design standard imported from RSWall.
   
6. Select Analysis > Compute to compute the model.
7. Select Analysis > Interpret . Open all segments in the Interpreter.

The results will display as they are shown below (Master Scenario):

This concludes Tutorial 2.