VERTICAL PARABOLIC CURVE

1. Objective(s):

The activity aims to locate the location of the highest point on the curve and to determine the existing ground elevation of specific points of the curve.

2. Intended Learning Outcomes (ILOs):

The students shall be able to:2.1 Use the total station to determine the elevation of points.2.2 Locate the station of the highest point.

3. Discussion:

To layout the vertical parabolic curve with given grade lines and appropriate length of the curve, the existing ground elevations of different stations must be known first by making necessary surveying procedures. Then, computing the proposed curve elevations of each station on the curve and comparing it to the actual ground elevations, we can determine the necessary amount of fill or cut on the ground in order to attain the exact elevations of points on the curve.

4. Resources:

1 Total Station

2 Prisms

2 Rods

1 Steel Tape

1 Chalk

5. Procedure:

1. Set up the instrument on a comfortable place to sight.

2. Do the necessary programs on the instrument.

3. Determine the difference in elevation and horizontal distance between the benchmark and the

chosen BVpC.

4. Determine the difference in elevation and horizontal distance between the BVpC and EVpC.

5. The Difference in horizontal between BVpC and EVpC will serve as the length of the vertical

parabolic curve.

6. Compute for the elevations of the BVpC and EVpC relative to the designated elevation of the

benchmark.

7. Compute for the location of the highest point of the curve on the existing ground.

8. Stake out the location of the highest point of the curve on the existing ground.

9. Determine the existing ground elevation of the highest point.

Course: BSCE Field No.: 4

Group No.: 4 Section: CE41FB4

Group Member: Date Performed: August 23, 2013

Kenneth Austin d.C. Pangilinan Date Submitted: August 30, 2013

Instructor:

Engr. Jenereth Almienda

6. Data and Results:

Station dHD (m) dVD (m)

Benchmark – BVpC 5.128 -0.286

BVpC – EvpC 67.316 0.491

EVpc – High Point 20.196 -0.013

Station Elevation (m)

BVpC 99.714

High Point 100.192

EVpC 100.205

6.2 Computations

g1 = +4%g2 = - 6%L1 = 2L/3Elevation of Benchmark = 100m

y = 26.641 mz = 43.191 mB = 148°22’05”

7. Sketch:

8. Conclusion:

In laying out a vertical parabolic curve, several stations must be considered. Existing ground elevations and and proposed curve elevations must be known in order to know how much filling up or cutting out of the ground must be done in order to meet the necessary elevations of the curve. The total station is an instrument which can be used to determine the elevations on the ground efficiently.