TerraForm

The TerraForm module in iCAD provides comprehensive tools for analyzing and visualizing earth modification works, enabling accurate quantity estimation for complex cut and fill operations. This powerful module addresses the significant challenges designers face when working with ground surface modifications.

Overview

TerraForm excels at handling intricate earthwork projects including:

Earth and Embankment Dams - Complete dam structure analysis
Bunds - Agricultural and industrial bund designs
Dykes - Flood protection and water management structures
Saddle Dams - Supporting dam infrastructure
Trench Excavations - Complex excavation and backfill operations

The module automatically processes quantity calculations while providing detailed 3D visualization of earth modification works, whether in cut or fill operations.

Design Conventions

Understanding the following conventions is essential for successful TerraForm implementation:

Axis Orientation

The centerline axis is drawn from right to left, facing downstream (FDS)
When standing at the beginning station looking downstream:
- Left side = Upstream direction
- Right side = Downstream direction

Figure: Axis orientation showing upstream and downstream directions.

Section View Standards

Section views consistently display:
- Left side = Upstream
- Right side = Downstream
This applies to both the iCAD interface and Assembly Editor

Figure: Section view orientation with upstream and downstream labeling.

Prerequisites

Before starting a TerraForm session, you must prepare two essential objects in AutoCAD:

1. Axis Object

The axis object represents the centerline of your earth formation and serves as the foundation for all TerraForm calculations.

Requirements:

Direction: Drawn from left to right, facing downstream
Reference: Must be properly referenced in AutoCAD
Profile Data: Must contain profile data generated using the AlignmentProfile module
Location: Typically drawn over a contour or feature map for reference

Profile Resolution Guidelines:

The quality of your results depends directly on the profile data resolution. Use these recommended settings:

Project Type	Offset Range	Increment	Use Case
Earth Dams	-100:10:100	10 meters	Large-scale dam projects
Small Dams & Bunds	-50:5:50	5 meters	Smaller embankment structures

Tip: Higher resolution (smaller increments) provides more accurate results but increases processing time. Choose the appropriate balance for your project needs.

2. Host Object

The host object serves as the data container for all TerraForm design information and analysis results.

Key Characteristics:

Stores all session data and calculations
Must remain in AutoCAD throughout the project lifecycle
Should be properly tagged for identification
Critical: Never delete this object - doing so may make all stored information inaccessible

Best Practice: Generate your host object using CadTools > Generate Host Sketch to ensure:

Automatic tagging
Consistent formatting
Proper data structure

Figure: Generating a host object using CadTools for consistent data storage.

Important Limitations

⚠️ Note: TerraForm works optimally with single embankment reaches. Avoid modeling works that extend across multiple reaches, as this can compromise result accuracy and presentation quality.

Figure: Example showing the limitation of single embankment reach modeling.

Starting a TerraForm Session

Creating a TerraForm session follows the standard iCAD module workflow. This section guides you through the complete setup process.

Step 1: Launch the Module

Access Module Browser: Open the Module Browser from either:
- The iCAD main interface
- The workspace browser
Select TerraForm: From the module list, choose TerraForm and click Continue

Figure: Module Browser interface showing TerraForm selection.

Step 2: Create New Session

Name Your Session: When prompted, enter a descriptive name for your session
Select Host Object: On the New Session dialog:
- Click the first object type listed
- Return to AutoCAD and select your prepared host object
Start Fresh Option: If the host object contains no stored data, the Start Fresh dialog appears
- Choose Pick Alignment to begin

Figure: New Session dialog for creating a fresh TerraForm session.

Step 3: Select Alignment

Pick Alignment Object: In AutoCAD, select your referenced alignment object
Verify Profile Data: Ensure the object contains the required profile data
Session Initialization: Upon successful selection, TerraForm displays the profile data in the main axis view

Figure: TerraForm interface showing profile data visualization.

Step 4: Access Workflow Tools

All TerraForm functionality is organized under the Workflow menu. From here you can:

Create and manage assemblies
Generate views and cross-sections
Calculate volumes and quantities
Export results and drawings

The following sections detail each workflow component and how to use them effectively for earth formation analysis.

Creating Assemblies

Assemblies are the fundamental building blocks of TerraForm analysis. They define the cross-sectional geometry of earth formations at various design levels, enabling accurate volume calculations and 3D visualization.

Understanding Assemblies

Purpose: Assemblies describe the geometric shapes of different earth formations:

Bunds: Finished fill profiles and slope configurations
Earth Dams: Complete dam structures including filter zones and impervious cores
Trenches: Excavation profiles and backfill configurations

Key Role: Assemblies process formation data against existing ground levels, providing the foundation for all quantity calculations and design visualization.

Assembly Types

TerraForm supports two primary assembly categories:

Simple Assemblies

Definition: Standard iCAD shape definitions without additional constraints
Use Case: Basic earth formations with uniform cross-sections
Components: Design level object + Shape data

Compound Assemblies

Definition: Combinations of two assemblies with additional geometric constraints
Use Case: Complex formations requiring multiple material zones
Features: Advanced shape control and material specification

Assembly Components

Every assembly requires two essential components:

Design Level Object: Defines the elevation profile along the alignment
Shape Data: Specifies the cross-sectional geometry and material zones

Figure: Assembly components showing design level and shape data integration.

These components work together to create complete spatial formation definitions, enabling TerraForm to generate accurate cross-sections, volume calculations, and 3D visualizations.

Creating Design Levels

Design levels define the elevation profiles for different formation zones along your alignment. These levels serve as the foundation for assembly creation and must be carefully prepared in AutoCAD.

Step 1: Prepare Profile Drawing

Design levels are created directly in AutoCAD using the profile drawing of your axis object. This approach allows for precise elevation control and visual verification of design intent.

Figure: AutoCAD profile drawing showing axis object with elevation data.

Step 2: Define Formation Levels

For complex projects like earth dams, multiple design levels are typically required. The following example shows three essential levels for dam construction:

Earth Dam Design Levels:

Crest Level: Top elevation of the dam structure
Core Level: Elevation of the impervious core zone
Blanket Level: Elevation of filter/transition zones

Figure: Multiple design levels showing crest, core, and blanket formations.

Step 3: Object Preparation

Before proceeding with assembly creation, ensure all design level objects are:

Properly Referenced: Objects must be correctly referenced in AutoCAD
Appropriately Tagged: Each object needs a unique, descriptive tag
Naming Convention: Use underscores instead of spaces or hyphens in tags

Important: Design level object tags can only contain letters and underscores. Numbers cannot be at the beginning, and spaces are not allowed.

Creating Simple Assemblies

Simple assemblies are the foundation of TerraForm analysis. This section guides you through creating and configuring these essential components.

Step 1: Launch Assembly Editor

Access Assembly Editor: Navigate to Workflow > Show Assembly Editor
Interface Overview: The Assembly Editor provides tools for creating, editing, and managing assemblies

Figure: Assembly Editor interface for creating and managing assemblies.

Step 2: Create New Assembly

Start Creation: Click New… in the Assembly List
Pick Object Dialog: Select Pick Level button
Select Design Level: Return to AutoCAD and pick your desired design level object
Variable Editor: The Variable Editor dialog opens with assembly configuration options

Figure: Pick Object dialog for selecting design level objects.

Step 3: Configure Assembly Properties

In the Variable Editor dialog, define your assembly characteristics:

Assembly Tag:

Used for listing in the Assembly Editor interface
Must contain only letters and underscores
Numbers cannot be at the beginning
No spaces allowed

Earth Shape Configuration:

Defines embankment formation on left and right sides of centerline
Use drop-down selector for preset values
Both left and right specifications are required for valid assembly

Figure: Variable Editor dialog for configuring assembly properties.

Step 4: Complete Assembly Creation

Apply Changes: Click Apply to create the assembly
Management Tools: Use provided buttons to edit or delete assemblies as needed

Figure: Assembly management interface showing created assemblies.

Step 5: Create Additional Assemblies

Repeat the process for each design level (e.g., core and blanket assemblies for earth dams):

Figure: Multiple assemblies created for different formation levels.

Step 6: Edit and Review Assemblies

Select Assembly: Choose from the assembly list to highlight in the graph area
Edit Configuration: Click Edit button to modify assembly settings
Review Settings: Verify all configurations meet design requirements

Figure: Assembly editing interface for reviewing and modifying settings.

Step 7: Update and Synchronize Views

After creating assemblies, synchronize the interface:

Save to Host: Save all assembly data to the host object
Reload Assembly: Use Workflow > Reload Assembly to refresh data
Refresh View: Update the main interface display

💡 Tip: If assemblies don't appear correctly, use the sequence: Save to Host → Workflow > Reload Assembly → Refresh View

Step 8: Dynamic Cross-Section Viewing

Access Workflow > Cross-section View to interact dynamically with assemblies:

Drag the section bar along different stations
View real-time cross-sections in both main interface and Assembly Editor

Figure: Dynamic cross-section view showing assembly interaction.

Creating Views

With assemblies properly configured, TerraForm can generate comprehensive views that help refine designs and respond to ground conditions. This section covers both section views and plan views.

Section Views

Section views provide detailed cross-sectional analysis at any point along your alignment, enabling precise evaluation of earth formation geometry.

Interactive Section Generation

Method 1: Interactive Selection

Switch to Profile View: Press Ctrl+R to change to default (profile) view
Launch Section Tool: Access Workflow > Show-section
Interactive Tool: A dynamic tool is created that updates the Assembly Editor window in real-time
Select Location: Click anywhere on the profile to generate the section view

Figure: Interactive section tool for dynamic cross-section generation.

The section view for the selected location appears in the main iCAD interface:

Figure: Generated section view showing detailed cross-section analysis.

Method 2: Direct Station Input

Access Go To Command: Use Workflow > Go To menu command
Input Station: Enter the required station value in the Input STA dialog
Generate Section: The system creates the section view for the specified station

Figure: Station input dialog for direct section generation.

Pool Level Configuration

Pool level information enhances visualization by displaying water surface elevations:

Configuration Options:

Text and Elevation: Adjustable via Workflow > Variable Editor
Display Control: Set Display Flood Level variable to control visibility
Positioning: Use offset values for text placement

Figure: Pool level configuration in Variable Editor.

Pool Level Settings:

0.0: Suppresses pool level text display
Negative Values: Renders text on the left (upstream) side
Positive Values: Renders text on the right (downstream) side

Creating Plan Views

TerraForm generates high-quality plan views that accurately represent earth formations from above, providing essential visualization for design review and documentation.

Plan View Features

Key Capabilities:

Ground Surface Integration: Combines existing ground surface with top-most assembly
Slope Edge Display: Shows precise slope edges and transitions
Direction Indicators: Hair lines indicate slope directions and flow patterns
AutoCAD Export: Generates scaled drawings ready for AutoCAD import
Presentation Quality: Professional-grade output suitable for reports and presentations

Plan View Examples

Straight Axis Alignment: This example shows a straight axis alignment with contours hidden under fill areas, demonstrating clean visualization of earth formation boundaries.

Figure: Plan view of straight axis alignment with hidden contours under fill.

Curved Axis Alignment: This example demonstrates how TerraForm handles complex curved alignments while maintaining accurate plan view presentation, showing precise formation boundaries and slope transitions.

Figure: Plan view of curved axis alignment showing accurate formation presentation.

Generating Plan Views

Access Plan View Tool:

Launch Command: Navigate to Workflow > Plan View
Configure Options: Choose contour generation settings as desired
Generate View: Proceed with plan view creation
Export Options: Select scaling and export format for AutoCAD integration

The system automatically uses the top-most assembly in your assembly list as the reference for plan view generation, ensuring consistent and accurate representation of your earth formation design.

Generating Fill Work Estimates

With assemblies properly configured, TerraForm can calculate accurate volume estimates for all earthwork operations. This section covers the volume calculation process and result interpretation.

Volume Calculation Process

Step 1: Launch Volume Calculation

Access Command: Navigate to Workflow > Calculate Volumes
Initiate Process: The system begins processing volume calculations for all assembly areas

Figure: Volume calculation command in the Workflow menu.

Step 2: Monitor Calculation Progress

The calculation process displays a progress bar showing:

Current processing status
Estimated completion time
Station-by-station processing updates

Figure: Volume calculation progress bar showing processing status.

Step 3: Review Results

Data Table Display:

Results are automatically sent to the Data Table
If not visible, toggle table visibility from the toolbar menu
Results include detailed volume breakdowns for each assembly

Figure: Data table displaying calculated volume results.

Understanding Volume Results

Volume Categories:

Individual Assembly Volumes: Net volumes for each assembly (single or combined)
Cumulative Volumes: Total volumes from start to current station (shown in last row)
Station-Based Calculations: Volumes calculated for each partial station interval

Calculation Method:

Technical Note: TerraForm uses the trapezoidal method of integration to calculate volumes at each partial station and across the entire station range. This method provides accurate volume estimates by approximating the area under the curve using trapezoidal segments.

Volume Calculation Methodology

TerraForm employs the trapezoidal integration method for precise volume calculations. This mathematical approach ensures accurate estimation of earthwork quantities across complex formations.

Figure: Trapezoidal integration method visualization for volume calculations.

Mathematical Foundation:

The volume calculation method generalizes to the following formula:

Figure: Mathematical formula for trapezoidal volume calculation method.

Where:

x1, x2, ..., xn: Station locations for calculations in the range of interest
A(xi): Cross-sectional area at station xi
Δx: Station increment between calculation points

Data Export and Documentation

Copy Table Functionality:

Use the Copy Table button to export results
Data can be pasted into spreadsheet applications (Excel, OpenOffice)
Enables further analysis and documentation
Supports integration with external reporting systems

Assemblies with Tracer (Bees)

Tracer assemblies provide advanced geometric control by incorporating additional constraints that dynamically modify assembly shapes along the alignment. These constraints enable complex formations that respond to specific design requirements.

Understanding Tracer Constraints

Definition: Tracer assemblies include geometric constraints defined using AutoCAD objects representing plan view constraints.

Purpose: Constraints control the extent to which assembly parameters (b,m,h triplet) extend at any given station, enabling:

Variable width formations
Complex geometric transitions
Site-specific shape modifications

Figure: Plan view of fill work showing schematic tracer lines for geometric constraints.

Tracer Line Requirements

Object Preparation:

Scale: All tracer lines must be drawn to scale
Reference: Must be referenced to a valid axis pair
Tagging: Must be properly tagged for identification
Geometry: Represents the plan view of desired constraint

Adding Tracer Constraints

Step 1: Select Assembly

Choose Assembly: Select the target assembly from the list box
Access Tracer Tool: Click the Bee button to activate tracer mode

Step 2: Select Tracer Object

AutoCAD Selection: AutoCAD enters select mode with prompt "Pick a Tracer Object:"
Choose Object: Select the prepared tracer line object
Apply Geometry: The selected object's geometry is applied to the assembly

Figure: Tracer object application to assembly configuration.

Step 3: Configure Application

Edit Assembly: Click the Edit button to access configuration
Verify Inclusion: Confirm the selected object appears in the last row
Choose Side: Select application to either left or right side of assembly (rows 4 or 5)

Dynamic Assembly Behavior

Real-Time Updates: Cross-section views now show assemblies dynamically changing size and shape as the section line moves along different stations, reflecting the tracer constraints.

Visualization: The main interface displays how tracer constraints affect assembly geometry at each station location.

Important Limitations and Notes

⚠️ Critical Limitations:

Top Assembly Restriction: Tracer bees cannot be applied to the top-most assembly in the list. If lower assemblies with tracer data are moved up, the tracer data will be cleared upon reload.

Station Assignment: Assigning different assembly sets for different station sections is not currently supported.

Coordinate Editing:

Tracer line and design level coordinates can be updated using Workflow > Reload Assemblies
Never edit starting coordinates - if modified, re-reference objects before reloading

💡 Tip: Use Workflow > Reload Assemblies to update tracer line or design level changes without leaving the session.

Modified Ground Levels Processing

Real-world earthwork projects often require fill operations over prepared ground surfaces that differ significantly from original ground levels. TerraForm's Modified Ground Levels (MGL) feature enables realistic modeling of these conditions, producing accurate drawings and quantity estimates.

Understanding Modified Ground Levels

Purpose: MGL processing allows fill works to be modeled above excavated or prepared ground levels rather than original ground surfaces.

Applications:

Foundation preparation for embankments
Trench excavation and backfill operations
General Foundation Level (GFL) modeling
Realistic earthwork quantity calculations

Initial Setup

Current State: Fill works are initially drawn over existing ground level, as shown in the example assembly definition.

Figure: Initial assembly definition showing fill works over existing ground level.

Creating Modified Ground Levels

Step 1: Launch MGL Creation

Access Command: Navigate to Workflow > Create MGL
Select Assembly: Choose the Trench assembly representing the General Foundation Level (GFL)
Confirm Selection: Click Ok to proceed

Figure: Pick Assembly dialog for selecting GFL trench assembly.

Step 2: Monitor Processing

Progress Tracking:

Progress bar displays calculation status
Status bar shows detailed processing information
Results are automatically sent to the Data Table view

Figure: Progress bar and status display during MGL processing.

Step 3: Review Results

Data Table Analysis:

Access Table View: Click the Table View toolbar if not already visible
Review Calculations: Results show Ground Level Modifications calculations
Summary Values: Highlighted summary values appear at the bottom of the table

Figure: Data table showing ground level modification results and summary values.

Managing Modified Ground Levels

MGL Control Options

Access Control: Navigate to Workflow > Create MGL again (notice the unchecked status)

Available Options:

Toggle: Switch MGL status on/off (check mark indicates active state)
Clear: Remove all modified ground level data and start over
Modify: Create additional modified levels for complex formations

Figure: MGL control dialog showing toggle, clear, and modify options.

Visualizing MGL Effects

Dynamic Section Viewing:

Launch Section Tool: Use Workflow > Show Section or press Ctrl+X
Interactive Review: Move cursor to see modified ground level effects
Visual Indicators: Thick gray lines indicate the new ground level

Figure: Section view showing modified ground level with thick gray line indicator.

Advanced MGL Processing

Adding Trench Modifications

Incorporating Complex Shapes:

Access Modify: Choose Modify option from MGL control dialog
Select Trench Assembly: Choose assembly representing deep trench geometry
Process Modification: System processes the additional ground level modification

Figure: Pick Assembly dialog for selecting deep trench modification.

Reviewing Volume Changes

Updated Calculations:

Access Table View: Review updated volume calculations
Highlighted Changes: Cumulative values show estimated volume changes
Summary Analysis: Bottom table values reflect all modifications

Figure: Data table showing updated volume calculations with highlighted changes.

Final Assembly State

Updated Assembly Editor: Fill works now extend to the newly modified ground level, showing realistic formation geometry.

Figure: Assembly editor showing fill works extending to modified ground level.

MGL Persistence

Data Management: Modified levels created through this process are automatically saved and available for further modification or use in subsequent analysis sessions.

Resolving modelling Issues

When working with alignments and their assemblies, it is often needed to update data to suit the desired layout. The following options are available.

Reload Alignment The alignment object may not have the right coordinates or the correct resolution of profile data. This can be adjusted at any time as follows:
- Close the Terrafrorm module (if open).
- Make the necessary adjustment to the alignment object (reverse, move...)
- Re-extract the profile data with the desired resolution, and save the data.
- Reopen the Terraform session, then go to Workflow > Reload Alignment menu command. The new profile data is brought, and updated.