A. Data Perencanaan
a. Mutu Baja (BJ) = 41 ; Fu = Mpa Fy = Mpa
b. Lebar bangunan (L) = m = cm
c. Tinggi bangunan (H) = + + = m
d. Panjang bangunan (B) = x m
e. Over stek = m
f. Kemiingan atap = 47o ; cos α = sin α =
g. Bahan penutup atap = seng = kg/m2 tan α =
h. Jarak antar kuda-kuda = m = cm h atap = m
i. Beban mati = Kg/m2
j. Beban hidup = Kg/m2
B. Menghitung jarak antar purlin
c a = mm
c = mm
1/2 c = mm
b 1/2 c +a = mm
a
47o 6 = 6 purlin daerah a = 9
3.64865 = 3 purlin daerah c = 6
mm mm
# Menentukan panjang atap +
# Perencanaan purlin
Maka, jarak antar purlin : (sama dengan jarak maksimu sagrod) b
n
# Total purlin n = 2 (n+1)
= 2 ( 14 + 1 )
= 30 bh
# Cek jarak antar purlin
r = ( x 14 ) - 60
= cm r < b
< . . . Ok !!!
C. Menghitung beban yang bekerja pada purlin Desain Gording
Data perencanaan
a. Mutu Baja (BJ) = 41 ; Fu = Mpa Fy = Mpa
b. Lebar bangunan (L) = m = cm
c. Kemiringan atap = 47o
d. Atap asbes = kg/m2
e. Jarak antar kuda-kuda = m = cm
f. Jarak antar purlin = m
g. Tekanan angin = kg/m2
0.731
1.2 120
25
250
12 1200
1.8 180
0.775 2.56
cm
1025.047 1085.047
410
=
= 0.775 m
=
b 1400 6000
cos α
410 250
12 1200
7.00
5 7
10850.466 mm =
2.56
10.85
14 =
1.4
0.682
10.850 m
1400 6000
=
77.503
77.503 1025.0466
300 175
1.072 6.4
4.75 2.25
2053 8798 4399 6452
Menggunakan profil Light Lip Chanel 75 20
A = cm2 Zx = cm2
q = kg/m Zy = cm2
Ix = cm4 ix = cm ≤ 1 . . . Ok !!!
Iy = cm4 iy = cm . . . Ok !!!
# Menghitung beban yang bekerja pada gording a. beban mati
qbm sin α (y)
qbm cos α (x)
Gording = kg/m
Asbes = x 2.6 = kg/m
kg/m
Toeslagh = 10 % x = kg/m
= kg/m
= x cos α = x = kg/m
= x sin α = x = kg/m
= 1/8 x x L2 = 1/8 x x 1.82 = kg/m
= 1/8 x x 1/2L2 = 1/8 x x 12 = kg/m
b. beban hidup
beban hidup akibat pekerja (P) = kg
Px
= x cos α = x = kg
= x sin α = x = kg
= 1/4 x x L = 1/4 x x 1.8 = kg.m
= 1/4 x x 1/2L = 1/4 x x 0.9 = kg.m
c. beban angin
- Beban angin yang bekerja = kg/m2
- Kemiringan atap = 47o ≤ 65o
Koefisien angin tekan = ( 0,02 x α - 0,4 )
= harus positif
Koefisien angin hisap =
W Tekan (qwx) = x x 25 = kg/m
W Hisap (qwy) = x x 25 = kg/m
Angin Tekan ( Mx ) = 1/8 x x 22 = kg.m
Angin Hisap ( My ) = 1/8 x x 23 = kg.m
73.135 16.455
1.684 0.452 Mbm y
qbm x qbm y
Px 68.200 30.690
0.775
4.159 4.460
100
qbm
Py
P 100 0.682
4.159 4.460 Mbm x
Px
M Px
M Py
68.200
P 100 0.731 73.135
125 4
0.775
3.560 1.984
0.391
5.544 0.554 5.544
Py
10.463 -7.750
10.463 4.237
25
0.54 -0.4
0.54 0.775
-7.750 -3.139
-0.40 Py
68.0
14.30 5.40 7.84 2.71 9.34
3.56 573
qbm
6.098
0.731 6.098
0.682 6.098 qbm
qbm x qbm y
qbm
qbm
d. Menghitung beban kombinasi
1. U = 1.4 D 2. U = 1.2 D + 0.5 L 3. U = 1.2 D + 1.6 L + 0.8 W 4. U = 1.2 D +1.3 W + 0.5 L
Jadi : Mux = = N.mm
Muy = = N.mm
Asumsi penampang kompak
Mnx → Zx x fy = x = N.mm
Mny → Zy x fy = x = N.mm
Untuk Mengatasi Masalah Puntir maka Mny dapat dibagi 2 sehingga
0.9 x 0.9 x
+ ≤ 1
≤ 1 . . . Ok !!!
e. menghitung lendutan (defleksi)
- beban yang menentukan adalah beban mati dan beban hidup qx = qbmx + qwx
= + = kg/m = kg/cm
qy = qbmy + qwy
= + = kg/m = kg/cm
Px = kg
Py = kg
x qx x l4 Px x l3
x E x Ix 48 x E x Ix
5 x x 4 x 3
x x 106 x 48 x x 106 x
= +
= cm
5 x x 4 x 3
x x 106 x 48 x x 106 x
= +
= cm δtotal = dx * cos α dy * sin α
= * + *
= cm
> = ^ + ^
cm > cm . . . Ok !!!
> . . . Ok !!!
Q Arah X Kombinasi Beban
2.358 ( kg/m )
5400 250
3575000 1350000
Mux
3575000 545152.306 +
1350000 268706.422
Q Arah Y
( kg/m ) 0.632 8.770 26.871 8.770 M Arah X M Arah y ( kg.m ) ( kg.m )
5.823 6.244
39.091 41.920
122.481 122.369
52.693 41.920
17.366 54.515 22.875
δx
384
5 +
4.159 10.463 14.622
384 2.1 573
0.1462 120
0.14622
4.460 7.750 12.210 0.1221
2.1 68.200
2.1 57758400000
117849316.6
≤ 1
0.169 0.2212
= 462067200000 151602058
+ +
68.200 73.135
=
573 120
0.391
0.731 68 126598348 + 126377919.6
54835200000 6854400000
0.00231 0.0184
=
0.02075
0.0024 2.000 0.02075 2.000
0.0209 240
0.00237
= 0.1221 120 + 73.135 120
384
0.017
0.017
0.00237 0.682 0.021 δy
2.1
L > δtotal
120 240 0.5
0.00033 0.002
=
68 Øb x.Mny
Øb x Mnx + Muy ≤ 1
54.515 26.871
545152.306 268706.422
14300 250
√(δ_𝑥 ^2+δ_𝑦^2)
√
= +
f. Design sagrod
beban yang bekerja = beban mati + beban hidup + beban angin/hujan pada sumbu X + beban purlin
a. beban mati
abm sin α (y)
abm cos α (x)
Gording = kg/m
Zinkalium = x 3 = kg/m
Sagrod = kg/m
kg/m
Toeslagh = 10 % x = kg/m
= kg/m
= x cos α = x = kg/m
= x sin α = x = kg/m
= 1/8 x x L2 = 1/8 x x 22 = kg m
= 1/8 x x 1/2 L2 = 1/8 x x 12 = kg m
b. beban hidup
beban hidup akibat pekerja (P) = kg
Px
= x cos α = x = kg
= x sin α = x = kg
= 1/4 x x L = 1/4 x x 2 = kg.m
= 1/4 x x 1/2 L = 1/4 x x 1 = kg.m
c. Beban sendiri gurt/purlin
P = kg/m
Px = P . Cos α
= x
= kg/m Maka beban yang menentukan adalah Px = kg
# Kombinasi pembebanan
P = + Px
= +
= kg
# Dimensi sagrod
P π x D2
G
= cm2 x D2
D2 = Diameter yang digunakan min
D = cm 4 mm
182.838 5.532
0.110
4 3.14
= 4
= A 0.1098
A = = 175.658
1600
0.139855109 0.37397207 abm
3.560
Py P 250 0.731 182.838
170.500
qbm x
M Px Px 170.500 76.725
M Py Py 41.139
Mbm y qbm y 0.560
250
Py
qbm
Px P 250 0.682 170.500
3.56 3.56
qbm y qbm 7.564 0.731 5.532
Mbm x qbm x 5.158 2.089
qbm 7.564
qbm x qbm 7.564 0.682 5.158
0.775
6.876
6.876 0.688
1.332 1.984
5.158 170.500
175.658 0.682 2.42791416
Desain menurut AISC (America Institute Steel Construction)
# Lebar efektif (gelagar dalam) Jarak antar gelagar = m
B a1 b a2
tp
5 x m
Bo = 4 /2 + 4 /2 = 3.5 m = 350 cm
L 4
= cm
a1 = a2 = 1/2 x
= cm
B2 = a1 + b + a2
= + + = cm Nilai B yang di pakai adalah
yang terkecil
a1 = a2 = 8 x tp B = cm
= 8 x 12
= 96 cm B3 = a1 + b + a2
= 96 + + 96 = cm
# WF yang digunakan a. beban mati
Slab beton bertulang t x = kg/m2
Plafon = kg/m2
Keramik = kg/m2
Spasi = kg/m2
= kg/m2
qDL = x
= kg/m
MDL = 1/24 x qDL x l2
x 2
= kg.m = kg.cm
344 3.5
350
1204
=
344
175.00
0.12 2400 288
11 24 175
7
700
350 35 350 735.0
1.8
35 227
162.54000 16254.000
1204 24
≤
B1 = 700
4
3.5
d1 d2
21 (tebal plat)
7 m
m 5
b. Beban yang bekerja
wt = kg/m2
qLa = wt x bo
= x
= kg/m
MLa = 1/8 x qDL x l2 = kondisi saat pelaksanaan
x 2
= kg.m = kg.cm
c. Beban hidup
wt = kg/m2
qL = wt x l
= x
= kg/m
MLL = 1/24 x qDL x l2
x 2
= kg.m = kg.cm
Rumus taksiran AISC
x G
x
= cm3
Dicoba profil 19
A = cm2 Ix = cm4
Wx = cm3 qbs = kg/m
mutu beton K-300
Ekomposit = + 20 % Ebeton *
= + √
= kg/m2 23500
# Angka ekivalen (n) Es
Ec
√ fc'
√
= diambil 9
Transformed Area Method
# Penentu garis netral
gn. Beton dc d = 12 cm
gn. Komposit
hs dt ds
gn. Baja Bs = 35 cm
2 B dc2 + 2 Fs dc - Fs hs = 0
2 dc2 + 2 dc - ( 12 + ) = 0
dc2 + dc - = 0
8.936174700210000 25 =
h 175.0 9 2300
40000 137
2100000
= w profil
24
= 350 7
8 2143.750
173.9
Ebaja
350
25 2106400
= h
= 4700210000
214375.000
250
250 3.5
100
100 3.5
350
0.2 6400
= 0.6616254.000001600 15.392
350
= 875
= 875 7
1786.458 178645.833
0.66 MDL
173.9 17.5
347.800 5130.050
350 12
173.9 38.889
-b + √ b2 - 4ac 2a
= + √ 2 - 4
2
= cm
ds = ( 12 + ) - ( 2 dc )
= -( 2 x )
= cm
Statis momen terhadap bagian atas slab beton ( Ac x Yc ) + ( As x Ys ) = ( At + Yt )
x x 6 ( 12 + ) = 12 x
9
+ = yt
yt = cm
GN Komposit didaerah Beton Ic Fc dc2
h
1 4 2 2
12 9
= + + +
= cm4
Analisa kekuatan berdasarkan metode pelaksanaan 1. Saat pelaksanaan
a. beban mati
Slab beton bertulang t x = kg/m2
bekisting = kg/m2 +
kg/m2
qDL= x
= +
= kg/m
MDL = 1/8 x qDL x l2
x 2
= kg.m = kg.cm
MDL = kg.m
Momen akibat beban kerja (beban pada saat pelaksanaan)
1 2 kondisi saat pelaksanaan
8
= kg.m
+
= kg/cm < kg/cm . . . Ok !!!
2. Saat Pemakaian a. beban mati
Slab beton bertulang t x = kg/m2
Plafon = kg/m2
Keramik = kg/m2
Spasi = kg/m2
= kg/m2
qDL = x + berat profil wf
= +
= kg/m
MDL = 1/24 x qDL x l2
x 2
= kg.m = kg.cm
MDL = kg.m
Momen akibat beban kerja (beban pada saat pelaksanaan)
1 2
24
= kg.m
29.50 7.8535
x 100
412.106 1600
2737.87500
1786.458
= dc
100 3.5
7 2143.750
5130.050 38.889
7.854
17.50
7
6 7.8535 9
= 7334.68750 2143.750 2300
x 3.5 x
Wx
MDL + MLL x 100 Gs
82379.350
7334.69
MWL =
+ 175.00
h + Fs ds2
Is + +
=
-347.8 347.8 38.889
33083.580
x x x
Itotal
yt
173.9 5130.050
1400.000 407.233
13.793 175.0 12.00
9
x
2737.87500 273787.500
1204 137
303 3.5
1197.5
= 1197.5 7
8 7334.68750
= 40000 + 175.00 6
40000 2100 7195.770306
=
MWL = x 250
0.12 2400 288
11 24 21
16.035 13.793
+ 173.9 17.5 175.00 +
+ 173.9
288 15 303
733468.750
1060.5 137
+ berat profil wf
0.12 2400
344
344 3.5
1341
= 1341 7
24
+ x x ( 13.793 + )
= kg/cm < kg/cm . . . Ok !!!
+ x x ( 13.7929 + )
9
= kg/cm < <
σ
c= σc/3.5
= 250/ 3.5< kg/cm . . . Ok !!!
3. Perencanna shear connector
B C D
QE
QA
qt= qDL+ qLL qt x
= + 2 2
= kg/m = kg
qt QC = 0
4
= x
4
= kg
4. Gaya geser longitudinal St = Fs x ds
= x
= cm3
St x QA St x QA
x x
= kg/cm = kg/cm
5. Gunakan stud connector
Diameter = mm
Tinggi = cm
H 45
d 16
Q = 10 x H x d x √ fc'
= 10 x 45 x x √
= N
= kg
Q Q
qa qb
= =
= cm = cm
6. Cek Lendutan (saat konstruksi)
1 x x 4 1 x x 4
x 106 x x 106 x
= cm = cm
+ <
cm < . . . Ok !!!
3670.978 19.096
17.5
2216 7
3878
Itotal qb = Itotal
= 2398.590 2398.590
71.4285714
7756 171.863
Gs = MDL Itotal+ MDL x ys
= 2737.87500 1786.458
GC = Mh x IDL + MtotalDL x ys
= 2737.87500 1786.458 100 17.5
82379.350 1600 82379.350 100
A E
QA
1341 875 =
2216
= 2216
7756
7
700
384 2.1
0.02605 S2 =
= qa
=
225.827 112.913
3878 82379.350 112.913
4.5 16
= = 2.8125
25.0 225.827
2398.590 82379.350
= 3670.978 = 3670.978
16
=
40000
16.256 32.511
36000
< L dTotal
0.875 0.875
0.08914 2.1 dBH = 3.500
32 16
dBM
384
11.975 700
40000
= QB =
173.900 13.793
S1
0.08914 0.0261 0.115
800