🛣️ROAD ALIGNMENT SURVEYING – HORIZONTAL CURVE SETTING
Horizontal curve setting is an important surveying operation used in road construction to establish smooth and accurate curved road alignments between two straight sections.
A Total Station is commonly used to set out the road centreline, inner edge and outer edge of a horizontal curve with high accuracy.
📌Key Components
1️⃣Road Alignment (Centreline): The reference line that defines the designed path of the road.
2️⃣ Inner Edge (Offset): The inside boundary of the curved roadway, established using calculated offsets from the centreline.
3️⃣ Outer Edge (Offset): The outside boundary of the roadway, marked according to the design width and curve geometry.
4️⃣ Total Station: An electronic surveying instrument used to measure horizontal angles, vertical angles and distances for accurate curve setting.
5️⃣ Prism (Range Pole): A reflecting target used with the Total Station to determine precise survey points on the ground.
📐Basic Procedure for Horizontal Curve Setting:
1. Study the approved road alignment and horizontal curve design.
2. Establish control points and benchmarks.
3. Set up and orient the Total Station.
4. Calculate curve parameters, including radius, tangent length and deflection angles.
5. Mark the road centreline points using calculated coordinates.
6. Establish inner and outer road edges using the required offsets.
7. Check all points for alignment, levels and design accuracy.
8. Transfer the final setting-out points to the construction team.
⚠️Important Engineering Note
The centreline and edge offsets must be calculated from the approved geometric design. Do not assume that the inner and outer edges are always parallel at a constant offset without considering the specified road geometry.
Proper horizontal curve setting ensures smooth vehicle movement, improved road safety, accurate earthwork quantities and better construction quality.
@etconp
Horizontal curve setting is an important surveying operation used in road construction to establish smooth and accurate curved road alignments between two straight sections.
A Total Station is commonly used to set out the road centreline, inner edge and outer edge of a horizontal curve with high accuracy.
📌Key Components
1️⃣Road Alignment (Centreline): The reference line that defines the designed path of the road.
2️⃣ Inner Edge (Offset): The inside boundary of the curved roadway, established using calculated offsets from the centreline.
3️⃣ Outer Edge (Offset): The outside boundary of the roadway, marked according to the design width and curve geometry.
4️⃣ Total Station: An electronic surveying instrument used to measure horizontal angles, vertical angles and distances for accurate curve setting.
5️⃣ Prism (Range Pole): A reflecting target used with the Total Station to determine precise survey points on the ground.
📐Basic Procedure for Horizontal Curve Setting:
1. Study the approved road alignment and horizontal curve design.
2. Establish control points and benchmarks.
3. Set up and orient the Total Station.
4. Calculate curve parameters, including radius, tangent length and deflection angles.
5. Mark the road centreline points using calculated coordinates.
6. Establish inner and outer road edges using the required offsets.
7. Check all points for alignment, levels and design accuracy.
8. Transfer the final setting-out points to the construction team.
⚠️Important Engineering Note
The centreline and edge offsets must be calculated from the approved geometric design. Do not assume that the inner and outer edges are always parallel at a constant offset without considering the specified road geometry.
Proper horizontal curve setting ensures smooth vehicle movement, improved road safety, accurate earthwork quantities and better construction quality.
@etconp
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