SOLVE FOR THE CLOSED TRAVERSE SURVEYING (Real Life Site Construction Calculation)

Introduction

This tutorial provides a step-by-step guide on closed traverse surveying, a method essential for establishing horizontal control in surveying. You'll learn how to perform calculations to reduce measurements and check for errors, making it relevant for construction and engineering projects.

Step 1: Understanding Traverse Surveying

• Definition: Traverse surveying involves a series of connected lines with known lengths and angles, used to establish control points.
• Purpose: It allows surveyors to quickly and accurately determine distances, earthwork volumes, and land areas.

Types of Traverse

• Closed Traverse: Forms a loop and returns to the starting point, allowing for error checking.
• Open Traverse: Does not return to the starting point, typically used for longer distances where closure is not necessary.

Step 2: Collecting Field Data

Instruments Needed

• Auto Level
• Surveying Tripod
• Survey Leveling Staff or Rod
• Plumb Bob

Methodologies

• Height of Collimation (HOC): This method involves checking site levels by calculating the height at which the surveyor's line of sight intersects the staff.
• Rise and Fall Method: This technique tracks changes in elevation by recording the differences in heights between points.

Step 3: Performing Traverse Calculations

1. Setup: Position the auto level and ensure it's properly leveled.
2. Record Measurements: Take readings at various points (backsight, foresight, and intermediate sights).
   • Backsight (BS): The first reading taken at a known point.
   • Foresight (FS): The reading taken at the point you are measuring to.

Calculating Levels

Using HOC

• Formula: Last Reduced Level - First Reduced Level

Using Rise and Fall

• Record differences and ensure the sum of rises equals the sum of falls for accuracy.
3. Error Check: Calculate the error of closure by comparing the initial and final points.

Step 4: Error Adjustment

• Error of Closure: Check the total latitude and departure to identify discrepancies in the traverse.

Adjustment Procedure

• Apply the double meridian distance method to adjust for any errors observed in your calculations.

Step 5: Final Data Summary

Create a Table: Summarize your findings in a clear table format that includes

• Baseline measurements
• Adjusted latitudes and departures
• Calculated errors and corrections
• Review: Ensure all data is accurate and reconciled with your initial measurements.

Conclusion

Closed traverse surveying is a critical skill in construction and site engineering, enabling precise measurements and error checks. By following these steps, you can effectively gather and analyze data for your surveying needs. For further learning, consider exploring advanced applications of the Auto Level and other surveying instruments in future projects.