TUGAS POLIGON DAN WATERPAS ILMU UKUR TANAH
OLEH : ALGAIL GREZELDA GUMINTANG 1541320027 / 03 1 MRK 3
JURUSAN TEKNIK SIPIL POLITEKNIK NEGERI MALANG 2016
BAB I SOAL 1. Data hasil pembacaan rambu pada pengukuran waterpas jalur tertutup sebagai berikut : RAMBU BELAKANG
RAMBU MUKA DAN
(cm)
PROFIL (cm)
NO TITIK
BA
BT
BB
BA
BT
BB
P
153
148
143
A
232.5
225.7
219
A
122.4
116.4
110.5
B
109.3
106
102.5
B
57.3
48.1
38.8
C
101.9
95.8
89.5
C
88.9
82.5
76.1
D
25.5
16.2
7.3
D
124.4
118.9
113.3
E
82.9
76.7
70.4
E
140
136.8
132.9
P
132.2
128.3
124.4
Hitung Elevasi (H) titik A,B,C,D,E sesuai prosedur, pada jaringan tersebut, jika Hp = 100,325 meter. (Hp + No. urut absen = 100,325 + 3= 103,325 m)
2. Data hasil pengukuran “sudut dalam” dan jarak mendatar suatu polion
A
A
B
C
D
E
A
TINGGI
PEMBACAAN ARAH HORIZONTAL
(meter)
TARGET
T.PSWT
tertutup sbb :
1.500
ALAT
1.450
1.420
1.474
1.410
1.502
1.602
JARAK (meter) ͦ
‘
"
U
0
0
0
B
179
53
0
E
50
30
45
B
179
53
0
A
216
15
0
C
306
17
40
B
287
56
30
D
18
28
20
C
56
39
20
E
148
22
15
D
321
58
45
A
100
20
30
E
50
34
20
B
179
1
15
Jika diketahui koordinat titik a : XA = -50,000 meter ; YA=15,000 meter A. Gambarlah (sket) poligon tersebut sesuai data B. Hitunglah koordinat poligon sesuai prosedur catatan : koordinat awal (XA,YA) + no. urut absen (meter) (XA = -47,000 meter ; YA = 18,000 meter)
42.550
37.020
56.350
19.730
23.130
BAB II PENYELESAIAN
SOAL 1 Menghitung Jarak
D = 100 x (BA − BB)
DAP = 100 x ((BAP + BAA ) − (BBP + BBA )) DAP = 100 x ((153,0 + 232,5) − (143,0 + 219,0)) DAP = 2350 cm
DAB = 100 x ((BAA + BAB ) − (BBA + BBB )) DAB = 100 x ((122,4 + 109,3) − (110,5 + 102,5)) DAB = 1.870 cm
DBC = 100 x ((BAB + BAC ) − (BBB + BBC )) DBC = 100 x (( `157,3 + 101,9) − (38,3 + 89,5)) DBC = 3.090 cm
DCD = 100 x ((BAC + BAD ) − (BBC + BBD )) DCD = 100 x ((88,9 + 25,5) − (76,1 + 7,3)) DCD = 3.100 cm
DDE = 100 x ((BAD + BAE ) − (BBD + BBE )) DDE = 100 x ((124,4 + 82,9) − (133,3 + 70,4)) DDE = 2.360 cm
DEF = 100 x ((BAE + BAF ) − (BBE + BBF )) DEF = 100 x ((140,0 + 132,2) − (132,9 + 124,4))
DEF = 1.490 cm
∑ D = DAB + DBC + DCD + DDE + DEF ∑ D = 1.870 + 3.090 + 3.100 + 2.360 + 1.490 = 14.260 cm
Menghitung Beda Tinggi ∆h = BTblk − BTmk
∆hPA = BTP − BTA ∆hPA = 148 − 225,7 = −77,7 cm ≈ −0,777 m
∆hAB = BTA − BTB ∆hAB = 116,4 − 10,6 = 10,4 cm ≈ 0,104 m
∆hBC = BTB − BTC ∆hBC = 48,1 − 95,8 = −47,7 cm ≈ −0,477 m
∆hCD = BTC − BTD ∆hCD = 82,5 − 16,2 = 66,3 cm ≈ 0,633 m
∆hDE = BTD − BTE ∆hDE = 118,9 − 76,7 = 42,2 cm ≈ 0,422 m
∆hEP = BTE − BTP ∆hEP = 136,8 − 128,3 = 8,5 cm ≈ 0,085 𝑚
∑ ∆h = ∆hPA + ∆hAB + ∆hBC + ∆hCD + ∆hDE + ∆hEP ∑ ∆h = −77,7 + 10,4 + −47,7 + 66,3 + 42,2 + 8,5 = 2 cm ≈ 0,002 m
Menghitung Koreksi Beda Tinggi δh =
δhPA =
dPA ∑d
d x(−fh) ∑d
x(−fh)
2.350
δhPA = 14.260 x(−2) = −0,3296 cm ≈ -0,0033 m
δhAB =
dAB ∑d
x(−fh)
1.870
δhAB = 14.260 x(−2) = −0,2623 cm ≈ -0,0026 m
δhBC =
dBC ∑d
x(−fh)
3.090
δhBC = 14.260 x(−2) = −0,4334 cm ≈ -0,0043 m
δhCD = δhCD =
dCD ∑d
x(−fh)
3.100 14.260
δhDE =
dDE
δhDE =
2.360
δhEP =
∑d
x(−fh)
14.260 dEP ∑d
1.490
x(−2) = -0,4348 cm ≈ -0,0043 m
x(−2) = -0,3310 cm ≈ -0,0033 m
x(−fh)
δhEP = 14.260 x(−2) = −0,2090 cm ≈ −0,0021m
Menghitung Elevasi Titik
H(titik) = Hawal + ∆h + δh
HA = HP + ∆hAP + δhAP HA = 103,325 + (−0,77) + (−0,0033) = 102,545 m
HB = HA + ∆hAB + δhAB HB = 102,545 + 0,104 + (−0,0026) = 102,646 m
HC = HB + ∆hCB + δhCB HC = 102,646 + (−0,477) + (−0,0043) = 102,165 m
HD = HC + ∆hCD + δhCD HD = 102,165 + 0,663 + (−0,0043) = 102,823 m
HE = HD + ∆hDE + δhDE HE = 102,823 + 0,422 + (−0,0033) = 103,242 m
HP = HE + ∆hEP + δhEP HP = 103,242 + 0,0085 + (−0,0021) = 103,325 m (sebagai kontrol hitungan)
SOAL 2 A.(dibaliknya) B. MENGHITUNG BACAAN SUDUT HORIZONTAL (β)
βA = JAB − JAE βA = 179°53′ 0′′ − 50°30′ 45′′ = 129°22′15′′
βB = JBC − JBA βB = 306°17′ 40′′ − 216°15′ 0′′ = 90°2′40′′
βC = JCD − JCB βC = 18°28′ 20′′ − 287°56′ 30′′ = −270°31′ 50′′ + 360° = 90°31′50′′
βD = JDE − JDC βD = 148°22′ 15′′ − 56°39′ 20′′ = 91°42′55′′
βE = JEA − JED βE = 100°20′ 30′′ − 321°58′ 45′′ = −222°21′ 45′′ + 360° = 138°21′45′′
MENGHITUNG KESALAHAN TOTAL SUDUT UKURAN ATAU CLOSSING ERROR POLYGON (fβ) fβ={(∑ β)-n.180°}={(∑ β)-(N-2).180°} (memakai sudut dalam) fβ={(βA +βB +βC +βD +βE )-(5-2).180°} fβ={(129°22'15''+90°2'40''+90°31'50''+91°42'55''+138°21'45'')-(5-2).180°} fβ={(540°1'25'')-540°} fβ=0°1'25''
Menghitung nilai koreksi sudut dan nilai sudut terkoreksi.
Nilai koreksi total = -fβ = -0°1′25′′
Besarnya koreksi setiap sudut ukuran (Δβ) Δβ = -fβ / N Δβ = -0°1′25′′ / 5 = -0°0′17′′
Nilai sudut terkoreksi : β = βu + ∆β o βA = βA u + ∆β βA = 129°22′ 15′′ + (−0°0′ 17′′ ) = 129°21′58′′ o βB = βB u + ∆β βB = 90°2′40′′ + (−0°0′ 17′′ ) = 90°2′23′′ o βC = βC u + ∆β βC = 90°31′50′′ + (−0°0′ 17′′ ) = 90°31′33′′ o βD = βD u + ∆β βD = 91°42′55′′ + (−0°0′ 17′′ ) = 91°42′38′′ o βE = βE u + ∆β βE = 138°21′45′′ + (−0°0′ 17′′ ) = 138°21′28′′
MENGHITUNG AZIMUTH/SUDUT JURUSAN (lihat sket)
αAE = JAE − JAU αAE = 50°50′ 45′′ − 0°0′ 0′′ = 50°50′ 45′′
αEA = αAE + 180° αEA = 50°50′ 4 5′′ + 180° = 230°50′45′′
αAB = JAB − JAU αAB = 179°53′ 0′′ − 0°0′ 0′′ = 179°53′ 0′′
αBC = αAB + βB − 180° αBC = 179°53′ 0′′ + 90°2′ 23′ − 180° = 89°55′40′′
αCD = αBC + βC − 180° αCD = 89°55′ 40′′ + 90°31′ 33′′ − 180° = 0°27′30′′
αDE = αDC + βD αDE = (αCD + 180°) + βD αDE = (0°27′ 30′′ + 180°) + 91°42′ 38′′ = 272°10′25′′
MENGHITUNG KESALAHAN TOTAL JARAK UKURAN DALAM ARAH X : (fx) dan ARAH Y : (fy)
1. Menghitung kesalahan total jarak ukuran arah Absis (fx) : fx = {∑(d . sin α)}
fx = {dAB . sin αAB + dBc . sin αBC + dCD . sin αCD + dDE . sin αDE + dEA . sin αEA }
fx = {42,550 . sin 179°53′ 0′′ + 37,020 . sin 89°55′40′′ + 56,350 . sin 0°27′ 30′′ + 19,730 . sin 272°10′25′′ + 23,130 . sin 230°50′45′′}
fx ={42,550 . 0,0020 + 37,020 . 0,9999 + 56,350 . 0,0080 + 19,730 . (-0,9993) + 23,130 . (-0,7718)}
fx = 0,0293
2. Menghitung kesalahan total jarak ukuran arah Ordinat (fy) : fy = {∑(d . cos α)} fy = {dAB . cos αAB + dBc . cos αBC + dCD . cos αCD + dDE . cos αDE + dEA . cos αEA } fy = {42,550 . cos 179°53′ 0′′ + 37,020 . cos 89°55′40′′ + 56,350 . cos 0°27′ 30′′ + 19,730 . cos 272°10′25′′ + 23,130 . cos 230°50′45′′} fy ={42,550 . (-0,9999) + 37,020 . 0,0013 + 56,350 . 0,9999 + 19,730 . 0,0379 + 23,130 .0,6360} fy = -0,0157
MENGHITUNG NILAI KOREKSI SETIAP JARAK UKURAN
Besarnya koreksi setiap jarak ukuran dalam arah X : δx = (d / ∑d) . (-fx) ∑d = dAB + dBc + dCD + dDE + dEA ∑d = 42,550 + 37,020 + 56,350 + 19,730 + 23,130 = 178,78 m dAB
δx1 = (
) . (−fx)
∑d
42,550
δx1 = (
) . (−0,0293) = -0,0070 m
178,78
dBC
δx2 = (
∑d
) . (−fx)
37,020
δx2 = (
) . (−0,0293) = -0,0061 m
178,78
dCD
δx3 = (
∑d
) . (−fx)
56,350
δx3 = (
) . (−0,0293) = -0,0092 m
178,78
dDE
δx4 = ( δx4 = (
∑d
) . (−fx)
19,730
) . (−0,0293) = -0,0032 m
178,78
dEA
δx5 = (
∑d
23,130
) . (−fx)
δx5 = (178,78) . (−0,0293) = -0,0038 m
Besarnya koreksi setiap jarak ukuran dalam arah Y : δy = (d / ∑d) . (-fy) dAB
δy1 = (
) . (−fy)
∑d
42,550
δy1 = (
) . (0,0157) = 0,2647 m
178,78
dBC
δy2 = (
∑d
) . (−fy)
37,020
δy2 = (
) . (0,0157) = 0,2303 m
178,78
dCD
δy3 = (
∑d
) . (−fy)
56,350
δy3 = (
) . (0,0157) = 0,3506 m
178,78
dDE
δy4 = ( δy4 = (
∑d
) . (−fy)
19,730
) . (0,0157) = 0,1228 m
178,78
d
δy5 = ( EA) . (−fy) ∑d 23,130
δy5 = (
) . (0,0157) = 0,1439 m
178,78
MENGHITUNG KOORDINAT POLIGON Xx = Xp + dPX sin αPX + δx Yx = Yp + dPX cos αPX + δy
XB = XA + dAB . sin αAB + δx1 = (-47,000) + 42,550 . sin 179°53′ 0′′ + (-0,0070) = -46,922 m XC = XB + dBC . sin αBC + δx2 = (-46,922) + 37,020 . sin 89°55′40′′ + (-0,0061) = -9,867 m XD = XC + dCD . sin αCD + δx3 = (-9,867) + 56,350 . sin 0°27′ 30′′ + (-0,0092) = -9,425 m XE = XD + dDE . sin αDE + δx4 = (-9,425) + 19,730 . sin 272°10′25′′ + (-0,0032) = -29,145 m XA = XE + dEA . sin αEA + δx5 = (-29,145) + 23,130 . sin 230°50′45′′ + (-0,0038) = -47,000 m (sebagai kontrol hitungan)
YB = YA + dAB . cos αAB + δy1 = (-47,000) + 42,550 . cos 179°53′ 0′′ + 0,2647 = -25,281 m YC = YB + dBC . cos αBC + δy2 = (-46,922) + 37,020 . cos 89°55′40′′ + 0,2303 = -25,003 m YD = YC + dCD . cos αCD + δy3 = (-9,867) + 56,350 . cos 0°27′ 30′′ + 0,3506 = 31,696 m YE = YD + dDE . cos αDE + δy4 = (-9,425) + 19,730 . cos 272°10′25′′ + 0,1228 = 32,567 m YA = YE + dEA . cos αEA + δy5 = (-29,145) + 23,130 . cos 230°50′45′′ + 0,1439 = 18,000 m (sebagai kontrol hitungan)