Surveying FW#7
Site Pictures:
Computations:
Given: d1 = 4.5 ° T = Rtan(I/2)
D = 7.5 ° T = 15.28tan(34.5/2) T = 4.74m
Full Chord = 2m
Ls = 24m TS to PI = (R + S/4)tan(I/2) + L/2 TS to PI = (15.28 + 0.92/4)tan(34.5/2) + 24/2
I = d1 + 4D TS to PI = 16.82m
I = 4.5 +4(7.5) PI to ST = 16.82m
I = 34.5 °
R = (Full Sta. * 180)/ pi*D
R = (2 * 180)/ pi * 7.5
R = 15.28m
Lc = 2I/D
Lc = 2(34.5)/7.5
Lc = 9.2m
S = Lc2/6R = (9.2)2/6(15.28)
S = 0.92m
FINAL DATA SHEET
FIELD WORK NO. 6 LAYING OF A PARABOLIC CURVE USING TRANSIT AND TAPE
DATE: 9/16/14 GROUP NO. 4 TIME: 12 - 4:30 pm LOCATION: Walls WEATHER: Sunny PROFESSOR: Engr. Alviento
DATA SUPPLIED:
d1= 4.5
D= 7.5
LET I = d1 + 4D
Length of Spiral = 24m
(As the site will permit, preferably 10m - 30m
Adopt full chord length of __2__m (Preferably 2m to 5m)
STATIONS
X-DISTANCE
FROM PC/PT
TANGENT
OFFSETS
OCCUPIED
OBSERVED
PC
TS
12m
0
2
6m
0.10m
PC
0
0.79m
3
6m
2.65m
4
12m
6.28m
PT
ST
12m
0
2'
6m
0.10m
PT
0
0.79m
3'
6m
2.65m
4'
12m
6.28m
SIGNATURE OF STUDENT
ADVANCED SURVEYING 40
Discussion:
In field work number 7, Laying of a spiral easement curve using transit and tape, we learned how to compute for the needed values in order to plot a spiral curve on the ground. Spiral curves are used instead of the normal simple curve in order to minimize the subtle change in curvature in order for the road to be safer for vehicles. When we plotted the computed data on the ground, we noticed that spiral curve resembles the simple curve but the change in curvature was not as subtle. The curvature gradually changes, it's as if you're passing through a straight path.
In the future, if ever I were assigned to road
Computations:
Given: d1 = 4.5 ° T = Rtan(I/2)
D = 7.5 ° T = 15.28tan(34.5/2) T = 4.74m
Full Chord = 2m
Ls = 24m TS to PI = (R + S/4)tan(I/2) + L/2 TS to PI = (15.28 + 0.92/4)tan(34.5/2) + 24/2
I = d1 + 4D TS to PI = 16.82m
I = 4.5 +4(7.5) PI to ST = 16.82m
I = 34.5 °
R = (Full Sta. * 180)/ pi*D
R = (2 * 180)/ pi * 7.5
R = 15.28m
Lc = 2I/D
Lc = 2(34.5)/7.5
Lc = 9.2m
S = Lc2/6R = (9.2)2/6(15.28)
S = 0.92m
FINAL DATA SHEET
FIELD WORK NO. 6 LAYING OF A PARABOLIC CURVE USING TRANSIT AND TAPE
DATE: 9/16/14 GROUP NO. 4 TIME: 12 - 4:30 pm LOCATION: Walls WEATHER: Sunny PROFESSOR: Engr. Alviento
DATA SUPPLIED:
d1= 4.5
D= 7.5
LET I = d1 + 4D
Length of Spiral = 24m
(As the site will permit, preferably 10m - 30m
Adopt full chord length of __2__m (Preferably 2m to 5m)
STATIONS
X-DISTANCE
FROM PC/PT
TANGENT
OFFSETS
OCCUPIED
OBSERVED
PC
TS
12m
0
2
6m
0.10m
PC
0
0.79m
3
6m
2.65m
4
12m
6.28m
PT
ST
12m
0
2'
6m
0.10m
PT
0
0.79m
3'
6m
2.65m
4'
12m
6.28m
SIGNATURE OF STUDENT
ADVANCED SURVEYING 40
Discussion:
In field work number 7, Laying of a spiral easement curve using transit and tape, we learned how to compute for the needed values in order to plot a spiral curve on the ground. Spiral curves are used instead of the normal simple curve in order to minimize the subtle change in curvature in order for the road to be safer for vehicles. When we plotted the computed data on the ground, we noticed that spiral curve resembles the simple curve but the change in curvature was not as subtle. The curvature gradually changes, it's as if you're passing through a straight path.
In the future, if ever I were assigned to road