How to Work with Survey Data Using AutoCAD Assignment

Working with Line Segments

Survey descriptions usually begin with line segments. For example, you might start from the most southwestern corner of a boundary and work clockwise around the property. Each segment is described using a bearing and a distance.

• Start with the ._LINE command.
• If you have coordinates (Northing and Easting), enter them directly; otherwise, pick any point on the drawing.
• Use the survey data to input the line: for example, @107.65<N28D45'21"E.
• Continue with the next segment: for example, @27.23<S61D14'39"E.

This method allows you to replicate survey data line by line until your boundary or figure is complete.

Transitioning to Curves

After line segments, survey data often introduces curves. In AutoCAD, curves are constructed using the ARC command. Tangent curves—curves that naturally continue from the direction of the previous line or arc—are the most common.

To construct a tangent curve:

Draw a perpendicular line from the end of the previous segment toward the inside of the curve.

Make this line the same length as the curve radius using the ._LENGTHEN command.

Rotate the line by the curve’s delta angle (negative for right curves, positive for left).

Use the three defined points (center, start, and end) to construct the curve with the ._ARC command.

This approach allows you to switch seamlessly between lines and arcs as you replicate survey descriptions.

Constructing Tangent Curves in AutoCAD

Tangent curves follow naturally from the direction of the previous segment. Understanding how to set them up correctly is essential for accurate survey representation.

Compound and Reverse Curves

When one curve directly follows another, their relationship matters:

• Compound Curve: The second curve goes in the same direction as the first.
• Reverse Curve: The second curve goes in the opposite direction.

For a reverse curve:

• Extend a radial line from the previous curve.
• Adjust it to match the radius of the new curve using ._LENGTHEN.
• Rotate it by the delta angle (positive for left, negative for right).
• Construct the arc using the three key points.

This ensures the new curve properly reflects its relationship to the previous one.

Completing Line Segments After Curves

Once a curve is complete, you may return to a line segment. Using the same process described earlier, enter the line by its bearing and distance. For example:

@116.77<N86D32'54"W

Repeating this process allows you to build a complete boundary that includes a mix of lines and curves.

Constructing Non-Tangent Curves in AutoCAD

Not all curves in survey data are tangent to previous entities. In such cases, orientation becomes more complex. AutoCAD provides ways to construct these non-tangent curves using either Chord Bearing and Distance or Radial Bearing.

Using Chord Bearing and Chord Distance

A chord is a straight line connecting the start and end of a curve. The chord bearing is the direction of this line, and the chord distance is its length.

• Begin by identifying the chord bearing in the survey data.
• If necessary, adjust it by 180° depending on the traversal direction.
• Draw the chord line using the same syntax as before, for example: @75.66<S30D57'08"E.
• Start the ._ARC command, select the start point, choose the E (end) option, and then use the R (radius) option to define the curve.

This method provides accuracy when the curve does not naturally continue from the previous segment.

Using Radial Bearing

Sometimes, survey data provides a radial bearing instead. This is the bearing from the start point of the curve to the center of the circle that defines the curve.

To use radial bearing:

• Start a line from the endpoint of the previous entity.
• Enter the radial bearing with its distance, for example: @75.00<S28D45'21"W.
• Use this point as the center of the arc.
• Follow the same steps as tangent curves to complete the arc.

This method works particularly well when chord data is unavailable.

Practical Applications of Survey Data Entry in AutoCAD

Accurately entering survey data into AutoCAD has far-reaching implications for engineering, architecture, and land management. Understanding both tangent and non-tangent curve methods ensures that your drawings match legal descriptions and field survey results.

Accuracy in Property Boundaries

Legal descriptions of property often rely on precise bearings and distances. Incorrectly entering survey data can result in property line disputes or errors in construction planning. AutoCAD provides the tools needed to ensure that the drawn boundaries match exactly what is recorded in deeds or plats.

Preparing for Civil and Structural Projects

Survey data is essential in projects such as roadways, subdivisions, and utility layouts. Entering this data accurately helps establish a correct base plan from which more detailed design work can proceed. Engineers and architects can then build upon this base with confidence, knowing the initial survey was digitized properly.

Summary of Key Steps

Working with survey data in AutoCAD can seem complex, but breaking it into steps makes it manageable.

1. Start with line segments: Enter bearings and distances using the ._LINE command.
2. Construct tangent curves: Use perpendicular or radial lines, rotate them by delta angles, and draw arcs.
3. Handle non-tangent curves: Apply chord bearing/distance or radial bearing methods.
4. Switch between lines and arcs: Continue until the boundary or figure is complete.
5. Verify accuracy: Always compare your drawing against the original survey notes or deed descriptions.

Using these methods, survey data can be accurately represented in AutoCAD, creating reliable digital drawings that serve as a foundation for design and construction.

Conclusion

AutoCAD, even without advanced civil add-ons, provides all the necessary tools for entering survey data. By mastering line segments, tangent curves, and non-tangent curves, you can confidently translate survey notes into precise digital drawings. This skill is not only vital for academic assignments but also for professional projects where accuracy in survey interpretation is critical.