Turning Points

Definition

Turning points refer to specific locations during a surveying process where the line of sight changes direction. These points are crucial for establishing accurate measurements and for ensuring proper alignment in the layout of construction projects. By identifying turning points, surveyors can create reliable maps and establish reference lines that are essential for effective land use planning and infrastructure development.

5 Must Know Facts For Your Next Test

1. Turning points are essential for creating accurate topographic maps, allowing surveyors to represent land features correctly.
2. In leveling operations, turning points help maintain the line of sight between the instrument and the target, ensuring precise height measurements.
3. Surveyors often use turning points as temporary markers that can be referred back to while moving through different sections of a project site.
4. Proper identification and measurement of turning points can prevent costly errors in construction, such as misalignment of structures.
5. Turning points can be marked using stakes or flags to ensure they are visible and easily identifiable during the surveying process.

Review Questions

• How do turning points contribute to the accuracy of surveying measurements?
  • Turning points play a significant role in enhancing the accuracy of surveying measurements by providing specific locations where the direction of sight changes. This allows surveyors to maintain a clear line of sight when measuring distances and angles. By carefully identifying and utilizing these points, surveyors can minimize errors that could arise from obstructions or changes in elevation, leading to more precise results in mapping and construction planning.
• Discuss the methods used to establish turning points in the field during a surveying project.
  • To establish turning points in the field, surveyors typically identify key locations based on the desired layout or topography. They may use instruments like transits or levels to measure angles and distances from these points. After determining the turning point locations, surveyors mark them using stakes or flags for easy reference. This process ensures that subsequent measurements can be taken with consistency and accuracy, enabling effective project execution.
• Evaluate the impact of accurate turning point identification on large-scale civil engineering projects.
  • Accurate identification of turning points significantly impacts large-scale civil engineering projects by ensuring that all elements align properly throughout construction. This is especially important for infrastructure such as roads, bridges, and buildings where precision is crucial for safety and functionality. Inaccurate turning point data can lead to misalignment, resulting in increased costs due to rework or even structural failure. Therefore, careful consideration and execution of turning point establishment are vital for successful project outcomes.

Related terms

Benchmark: A fixed point of known elevation used as a reference for measuring heights and elevations during surveying.

Transit: A surveying instrument used to measure horizontal and vertical angles, often employed in conjunction with turning points for precise angle measurement.

Leveling:

A surveying method used to determine the elevation differences between points, often utilizing turning points to ensure accurate readings.