Short Answer:

A traverse survey is conducted by measuring a series of connected straight lines between fixed points, known as traverse stations. At each station, both the distance between points and the angles between lines are measured using instruments like a theodolite and chain or tape.

The process includes setting up the instrument at each station, measuring horizontal angles between two lines, and measuring the lengths between the points. This data is then used to plot positions, check for errors, and draw maps. Traverse surveys can be open or closed depending on whether the survey ends at a known point or not.

Detailed Explanation:

How a traverse survey is conducted

Traverse surveying is a step-by-step method used to measure and mark the layout of land using connected straight lines. It is commonly used in civil engineering projects for creating maps, laying out roads, determining property boundaries, and other construction-related works. The survey can be either open or closed, depending on the type of project and area being covered.

To conduct a traverse survey correctly, certain instruments are required such as:

• Theodolite or total station: For measuring angles
• Chain or tape: For measuring distances
• Tripod, pegs, arrows: For marking stations
• Field book: For recording data

Steps to conduct a traverse survey:

1. Reconnaissance and Planning
   Before starting the actual survey, the surveyor visits the area to decide on the traverse stations. These are well-chosen points that are visible, stable, and suitable for instrument setup. The number of stations depends on the size and shape of the area.
2. Marking Stations
   Each station point is marked using wooden pegs or metal pins. These are placed firmly into the ground so that the survey instrument can be centered directly above them.
3. Setting up the Theodolite
   The theodolite is set up on a tripod above a station. The instrument is centered using a plumb bob or optical plummet and then leveled using the leveling screws and spirit bubble.
4. Measuring Horizontal Angles
   At each station, the horizontal angle between two lines (back sight and fore sight) is measured using the theodolite. This angle helps to understand the direction changes as the traverse moves from one station to another.
5. Measuring Distances
   The linear distance between two stations is measured using a chain, tape, or Electronic Distance Measurement (EDM) tool. These measurements are noted carefully and recorded in the field book.
6. Repeat at Each Station
   The same steps are repeated at all stations until the traverse is complete. If it’s a closed traverse, the survey ends at the starting point or another known point. In an open traverse, it ends at an unknown point like the end of a road or canal line.
7. Recording and Calculation
   All measurements are written down in the field book. Surveyors then calculate bearings, coordinates, and check for any closing errors. In a closed traverse, adjustments are made to balance angles and distances.
8. Plotting the Traverse
   Using the recorded data, the traverse is plotted on a sheet or digitally. This plot shows the shape and layout of the surveyed area.

Important Points:

• Always check the instrument level before taking readings.
• Avoid taking measurements in strong wind or poor visibility.
• Recheck angles and distances if anything looks wrong.
• Use both face left and face right readings for better accuracy.

Conclusion

A traverse survey is conducted by carefully measuring distances and angles between a series of connected points. It involves setting up instruments at each station, marking points, and recording data in a stepwise manner. This method is widely used in civil engineering projects for accurate land measurement and mapping.