25.6
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.
剖面水准测量和横断面测量是用于确定和记录地形高程的测量方法,常用于基础设施项目,如公路、铁路、运河和管道。这些方法为土方工程规划和拟定路线的对齐提供数据。
剖面水准测量沿固定线测量高程以创建垂直地形剖面。测量员在基准点(BM)设置水准仪并记录后视(BS)以确定仪器的高度(HI)。在沿线规律间隔处进行…