縦断測量と横断面

Profile leveling measures elevation changes along a fixed line to create a detailed vertical terrain map. Surveyors establish heights at various stations to understand ground slopes and terrain features. This data is essential for planning infrastructure projects like highways, railroads, and pipelines, ensuring proper alignment with natural topography.

When the instrument's range is exceeded, the surveyor takes a foresight reading at the last observed station before moving. At the new position, a backsight is recorded to establish the new height of instrument. This overlapping procedure ensures elevation data remains continuous and accurate throughout the survey.

Cross sections, measured perpendicular to the main route, capture elevation changes on both sides of the centerline. Stakes placed at specific distances from the centerline record elevation differences to assess ground slope and terrain features. This perpendicular data aids in earthwork calculations for cuts and fills.

Intermediate foresights capture elevation changes at regular intervals along the survey route, including significant features like slopes, ditches, and riverbanks. These readings create an accurate representation of terrain variation. Regular intervals ensure no critical elevation shifts are missed, providing comprehensive data for infrastructure design.

Profile leveling and cross-sectional data provide detailed elevation information needed to calculate cuts and fills for construction. By documenting terrain profiles and ground slopes, engineers can plan efficient earthwork strategies. This information ensures infrastructure aligns with natural topography while minimizing excavation and fill requirements.

The height of instrument is calculated by adding the backsight reading to the benchmark elevation. This establishes a reference level from which all intermediate foresights are measured. Accurate height of instrument calculations are critical for determining correct elevations at each station along the survey route.

Stations are marked as plus stations to identify their position relative to the survey start point. Survey notes document station locations, their corresponding elevations, and significant terrain features. This systematic documentation creates a complete record for design and construction planning, supporting infrastructure alignment with natural landscapes and maintaining level grades.