The Rocscience International Conference 2021 Proceedings are now available. Read Now

# 13 - Multiple Boreholes

## 1.0 Introduction

This tutorial provides instructions on how to model multiple boreholes with non-horizontal soil strata in Settle3. Before proceeding with the tutorial, make sure you’ve gone through Tutorial 01 – Settle3 Quick Start so you’re familiar with the product’s basic functions and features.

Topics Covered in this Tutorial:

• Multiple boreholes

• Multiple water level input

• Display options

Finished Product:

The finished product of this tutorial can be found in the Tutorial 13 Multiple Boreholes.s3z file. All tutorial files installed with Settle3 can be accessed by selecting File > Recent Folders > Tutorials Folder from the Settle3 main menu.

## 2.1 Project Settings

1. Select Analysis > Project Settings (CTRL + J) to open the Project Settings dialog.
2. In the General tab, make sure the Units are set as:

• Stress: Metric, stress as kPa

• Settlement: Millimeters

1. Click on the Soil Profiles tab. Notice that you can model either Horizontal Soil Layers or Non-Horizontal Soil Layers. In this tutorial we will model non-horizontal soil strata with multiple boreholes.

1. Select the Non-Horizontal Layers option.

2. There are five interpolation options available. For this tutorial we will use the Inverse Distance method.

3. Click on the Groundwater tab.

1. Check the Groundwater Analysis checkbox and change the Method to Grid.

2. Click OK to close the dialog.

## 2.2 Soil Properties

1. Select Soils > Soil Properties (CTRL + 8) or click on the Define Soil Properties icon in the toolbar.
2. For Soil Property 1, select the Immediate Settlement tab and check the box for Immediate Settlement.

3. Enter the below data:

 # Name Unit Weight (kN/m3) Sat. Unit Weight (kN/m3) Es (kPa) Esur (kPa) 1 Sand Fill 18 18 25000 25000
1. Select the Primary Consolidation tab and set the Material Type as Linear.

2. Enter the following values:

 mv (m2/kN) mvur (m2/kN) 0.0002 0.0002
1. Repeat the above steps for the next two soil layers and enter the data below.

 # Name Unit Weight (kN/m3) Sat. Unit Weight (kN/m3) Es (kPa) Esur (kPa) mv (m2/kN) mvur (m2/kN) 1 Sand Fill 18 18 25000 25000 0.0002 0.0002 2 Silty Sand 18 18 20000 20000 0.0002 0.0002 3 Dense Silty Sand 19 19 25000 25000 0.0002 0.0002
1. For Soil Property 4, leave the Immediate Settlement box unchecked.

2. Go to the Primary Consolidation tab and set the Material Type as Non-Linear.

3. Enter the following values:

 # Name Unit Weight (kN/m3) Sat. Unit Weight (kN/m3) Es (kPa) Esur (kPa) Cc Cr e0 OCR 4 Silty Clay 18 18 - - 0.38 0.01 1.1 0.7
1. Click OK to close the dialog.

1. Select Soils > Boreholes > Add Multiple Boreholes or click on the Add Borehole icon in the toolbar and select Add Multiple Boreholes.
2. Specify the Number of Boreholes To Add. For this tutorial, we will enter 4.

1. Enter the coordinates of the Boreholes from the chart below and click OK.

 Borehole Name Location X Y BH1 0 0 BH2 25 5 BH3 15 20 BH4 35 25
1. The Edit Borehole dialog will appear. Click on Insert Layer Below three times. The layers will fill in with the correct names automatically.

1. For each Borehole, specify the Thickness of each layer using the values below:

 Material BH1 BH2 BH3 BH4 Sand Fill 3 5 4 4 Silty Sand 5 6 7 8 Dense Silty Sand 10 12 8 10 Silty Clay 12 7 11 8
1. Click OK to close the dialog.

Your model should now look like this:

Use your mouse to rotate the model to get a closer look at the soil strata.

## 4.0 Loads and Field Grid

2. Keep the default settings and click OK. In the bottom right of the screen, specify the load location as x,y = 20,15.

3. Select Grid > Add Fieldpoint Grid (CTRL + G) or click on the Add Fieldpoint Grid icon in the toolbar.

1. Keep the default settings and click OK.

2. In the bottom right of the screen, specify the first point as x,y = -5,-5 m, and the second point as x,y = 40,30 m.

## 5.0 Groundwater Data

1. Select Groundwater > Edit Groundwater Grids.

2. In the dialog box that appears, check the Use borehole locations as XY-coordinates checkbox. We are going to specify the water depth at each borehole location.

3. Enter the below depth data:

1. Click OK to close the dialog.

2. Select Groundwater > Soil Groundwater Properties.

3. Check the Show only used properties checkbox.

1. Click on Sand Fill, then select Default Grid from the Grid to use dropdown. Then click on Apply To All.

2. Click OK to close the dialog.

You can now use the View Controls to view the Water Surface.

You can turn the water surface on and off by checking and unchecking the Water Surface checkbox. Uncheck the Field Point Grid option to turn the grid off and view the water surface more clearly.

## 6.0 Display Options

We’ll now take a look at the different viewing options associated with using multiple boreholes.

Click on the Groundwater Grid and Water Surface checkboxes to turn them off.

In the Depth/Soil Layers section of the right-side controls enter Location X: 5 Y: 5. Notice the change in the soil column below. The soil column changes will the input x-y location, and is determined by interpolating between the boreholes.

Click on Field Point Grid in the View Controls to turn the grid back on, and click on the Draw Materials on all Queries checkbox.

Click and drag the field point grid, or use the up and down arrow in the Depth/Soil Layers section of the right-side controls to move the grid up and down. Notice how the materials on the Field Point Grid are constantly changing.

Select Query > Query Planes > XZ Plane..

Place the plane approximately under the load. In the View Controls panel, uncheck the Draw Materials on all Queries checkbox. When the Draw Materials on all Queries option is deselected, the analysis results are displayed. Query planes can be placed in the XY, XZ, and YZ directions. 3-point planes can also be specified.

This concludes the Multiple Boreholes tutorial; you may now exit the Settle3 program.