A borehole project is a series of models that link together all the strata that are found in a series of boreholes. To create a series of borehole models, you need to right-click over the Models item on the project tree and select the option New Borehole.
Importing Borehole Data
After you have selected the option to create a series of borehole models, you will be asked to select a .csv file that contains the borehole information. This file needs to be formatted specifically for n4ce and an example is shown to the right.
The first line in the file contains the header information for each column of the .csv file. The Name column defines the name for each borehole. The Bearing and Incline columns are intended for future use where the borehole is inclined. These define the direction bearing and angle from the vertical of the borehole. A 0 should be entered for these two values.
The X, Y and Z columns define the ground level co-ordinates of the borehole. The remaining columns contain the names of the various strata data. The first line contains the name of the stratum and, for each borehole, the remaining lines define the depth of the top of each stratum below the previous stratum as measured from the borehole cores.
After the .csv file has been imported, n4ce will create a series of triangulated models. One model will always be called Ground Level which is formed from the ground coordinates of the boreholes. The remaining models represent the top of each stratum and use the names in the header line. The height values in these models will be calculated from the borehole ground level taking away all the strata depths above.
When these models are created, those representing the various strata are also associated with the ground level model. This makes it easy when querying boreholes or taking sections through the data. The DTM Menu chapter describes associated models and their use.
The DTM Boreholes option from the Design Menu gives you a few options to work with the imported borehole data and generates a simple pop-up menu as shown. Using these options, you should be working from the Ground Level model
The Query option allows you to query the information about any given borehole. You will be asked to indicate the borehole in question and a dialog will be displayed showing the borehole information. The various associated strata models will be searched for the corresponding points and the points will then be sorted in descending order of depth. The information will then be displayed in a dialog box as shown to the right. The Level column contains a level of the top of each of the strata and the Depth column contains the depth of the top of the strata from the ground level. The Thickness column contains the thickness between the tops of neighbouring strata.
The Create option allows you to create a point that is inserted into each model. The point could be created by various means, such as a simple insert or generation from CAD. To create the same point in all models, you will be asked to indicate the existing point and a new point will be created at the same location in each model. The height for the new points will be interpolated the models.
The Chart option allows you to create a chart for individual boreholes. When selected, you will be asked to select a borehole using the Borehole Chart Selection dialog box. This displays a list of all the points in the model, including any that do not represent boreholes. There is also a Scale field which will be used for the sizing of the chart. Once selected, you will be asked to position the chart in the model.
For the moment, the settings for plotting the borehole chart are very basic. All text and lines are drawn in white with the only user-definable options being the definition of the pattern used for the legend column. They are stored in the settings directory in a configuration file called BOREHOLE.INI.
Each code prefix that could be used for a stratum in a borehole has its own section defining four settings. The Colour setting defines the colour used for the pattern and the Pattern field defines the hatch pattern that can be used. This pattern can be a solid fill-in which case, the value should be set to <Solid>. The Scale field defines the scale of the pattern that is created, and in the case of a solid fill is ignored. The Description field defines a text label that is used in the strata column of the borehole chart
You should always define a setting for BH, or whatever code you use for the point at ground level. This will be used from the ground level down to the top of the first stratum. If a code prefix for a stratum that has not been defined has been used, the chart that is generated will be incorrect.
Part of BOREHOLE.INI
An Example Borehole Chart
The examples above show part of a BOREHOLE.INI file and a borehole chart that has been created. You should note that if a code prefix is not defined in the configuration file, there will be no strata description in the leftmost column and no hatch pattern will appear in the third column. The borehole chart is created as a series of individual CAD elements rather than as a symbol so that editing can take place. Should you wish to use this chart elsewhere in the project, use the CAD tools to create a project symbol.