縦断測量と横断面

Profile leveling and cross sections are essential surveying techniques for understanding terrain elevation, especially in projects like highways, railroads, and pipelines.

In profile leveling, elevation changes are measured along a fixed line to establish heights at various stations, creating a detailed map of the terrain's profile.

The surveyor sets up an instrument at a convenient point, records a backsight reading at the benchmark, and calculates the height of the instrument.

Intermediate foresights are taken at regular intervals along the route, marking points of elevation change, such as slopes, ditches, or river banks.

When the instrument's range is exceeded, it is moved, and continuity in elevation data is maintained by taking a foresight at the last observed station.

Cross sections, taken perpendicular to the route, capture elevation changes on both sides of the centerline.

Stakes are placed at specific distances from the centerline, and elevation differences are measured to assess ground slope and terrain features.

Profile leveling and cross-sections aid in planning earthwork for cuts and fills, maintaining gradients for roads and railways, and aligning infrastructure with natural landscapes.