Wk 1 Flashcards
define surveying
involves measuring (using tools/devices)distances, angles, and
elevations for mapping and construction purposes
define geodetic surveying
Used for large-scale projects
(greater than 250 km²) covering vast areas, considering Earth’s curvature (e.g. national mapping, satellite positioning)
define plane surveying
Used for small- to medium-scale
projects where Earth’s curvature is negligible (e.g.
land surveying, construction projects)
stages of surveying
Reconnaissance Survey - Preliminary examination of the site
Preliminary - Collection of data to prepare initial maps
Detailed - Precise measurement and mapping for design purposes,
Construction - Setting out and marking locations for structures based on design plans
Post-Construction - Verification of constructed features to ensure they align with the design specifications
Monitoring and Maintenance - Periodic surveys to assess structural behavior and monitor changes over time
whats the sexagesimal system
A traditional system using degrees, minutes, and seconds
What do these mean?
1°
1’
1’’
1° - degrees
1’ - mins
1’’ - seconds
What are these equal to ?
1°
1’
1° = 60 minutes (60’)
1’ = 60 seconds (60’’)
convert degrees to radian
θ 𝑟𝑎𝑑𝑖𝑎𝑛𝑠 = θ 𝑑𝑒𝑔𝑟𝑒𝑒 × π/180
Convert radian to degrees
θ 𝑑𝑒𝑔𝑟𝑒𝑒𝑠 = θ 𝑟𝑎𝑑𝑖𝑎𝑛𝑠 × 180/π
Degrees to sexagesimal to degrees
Define:
Cosecant
Secant
Cotangent
what’s the law of cosines?
+ for angle version
What quantities are important to be accurately measured during the tendering stage?
❑ Areas of land the project will occupy
❑ Volumes of material required in construction
❑ Movement of the earthwork volumes
Calculating volumes using cross-sections is
typically used for…
❑ Road or railway construction – embankments and cuttings
❑ River sections including flood banks
what’s the prismoidal formula?
Average End-Ares Formula
1) use average end formula
(use section 1, 4 x-sectional areas)
2) use average end formula for first 2 sections (A1,A2)
- Use prismoidal formula for sections 2,3,4
- add the two volumes
