CE121 Surveying
FIELD WORK NO. 5
LAYING OF A COMPOUND CURVE USING TRANSIT AND TAPE
OBJECTIVES:
To be able to lay a compound curve by incremental chords and deflection angle method.
To master the skill in leveling, orienting, and using transit effectively.
To work cooperatively with one’s group mates and efficiently perform the required task.
MATERIALS/INSTRUMENTS:
2 range poles
Chalks
50 meter tape
Theodolite
METHOD/PROCEDURE: The professor gives the following data:
I1= 60⁰ D 1= 3⁰
I2= 64⁰ D 2= 4⁰ Forward Tangent Direction: N45⁰E Station of PC: 10+ 003 Compute the elements of the compound curve given the data above.
Set the transit at PC. Level and orient the transit at the magnetic south while vernier A is at zero reading.
Sight the location of vertex V1 following the given direction of the back tangent T1 and mark the location on the ground at a distance T1 from PC.
Set the horizontal vernier to zero again and start locating intermediate points of the curve until your reach PCC using incremental chord lengths and their deflection angle from the backward tangent.
Upon reaching PCC, transfer the instrument at PCC.
Again level the instrument and with the telescope inverted position, sight the V1.
After locating V1, plunge the telescope into normal position and locate V2 which is along the line from V1 to PCC, and at a computed distance T2 from PCC.
Mark V2 with chalk.
Once again, set the horizontal vernier A at zero reading while sighting the position of V2.
Using the incremental chord lengths and their deflection angles, lay intermediate points of the second curve on the ground until you reach PT.
Methods of radius-estimating of horizontal curves:
Many groups, including transportation agencies, accident investigators and transportation researchers, would find an accurate, quick and safe method to estimate the radius of horizontal curves particularly useful. The radius estimating methods were
LAYING OF A COMPOUND CURVE USING TRANSIT AND TAPE
OBJECTIVES:
To be able to lay a compound curve by incremental chords and deflection angle method.
To master the skill in leveling, orienting, and using transit effectively.
To work cooperatively with one’s group mates and efficiently perform the required task.
MATERIALS/INSTRUMENTS:
2 range poles
Chalks
50 meter tape
Theodolite
METHOD/PROCEDURE: The professor gives the following data:
I1= 60⁰ D 1= 3⁰
I2= 64⁰ D 2= 4⁰ Forward Tangent Direction: N45⁰E Station of PC: 10+ 003 Compute the elements of the compound curve given the data above.
Set the transit at PC. Level and orient the transit at the magnetic south while vernier A is at zero reading.
Sight the location of vertex V1 following the given direction of the back tangent T1 and mark the location on the ground at a distance T1 from PC.
Set the horizontal vernier to zero again and start locating intermediate points of the curve until your reach PCC using incremental chord lengths and their deflection angle from the backward tangent.
Upon reaching PCC, transfer the instrument at PCC.
Again level the instrument and with the telescope inverted position, sight the V1.
After locating V1, plunge the telescope into normal position and locate V2 which is along the line from V1 to PCC, and at a computed distance T2 from PCC.
Mark V2 with chalk.
Once again, set the horizontal vernier A at zero reading while sighting the position of V2.
Using the incremental chord lengths and their deflection angles, lay intermediate points of the second curve on the ground until you reach PT.
Methods of radius-estimating of horizontal curves:
Many groups, including transportation agencies, accident investigators and transportation researchers, would find an accurate, quick and safe method to estimate the radius of horizontal curves particularly useful. The radius estimating methods were