CALCULATION REPORT
FOR CONVEYOR STRUCTURE T-1022
OWNER : PT ANTAM (PERSERO) Tbk
CONTRACTOR : PT WIJAYA KARYA (PERSERO) Tbk
PROJECT NAME : CONVEYOR MOPP FeNi-1
LOCATION : POMALAA, SULAWESI TENGGARA
CONTRACT DATE : 17 January 2012
A 09-05
2012 31 Approval DRP SMS AP BR AA
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Number STATUS
Originator Reviewed By
Approved By Reviewed By Approved By
PT. WIJAYA KARYA (PERSERO) Tbk PT ANTAM (PERSERO) Tbk
CALCULATION REPORT
FOR CONVEYOR STRUCTURE T-1022
REV DATE REVISION DETAIL ORIGINATOR
DRP
TABLE OF CONTENT
1. GENERAL
1.1. SCOPE 4
1.2. CODE AND STANDARD 4
1.3. REFERENCES 4
1.4. BASIC DESIGN 4
2. STRUCTURAL MODEL
2.1 3D STRUCTURAL MODEL 6
2.2 LONGITUDINAL AND TRANSVERSAL SECTION 7
2.3 LOADS APPLIED IN STRUCTURE MODEL 7
3. EXTERNAL LOADING CALCULATION
3.1 DEAD LOAD (D) 9
3.2 LIVE LOAD (L) 11
3.3 EARTHQUAKE LOAD (E) 12
3.4 WIND LOAD (W) 16
4. MEMBER DESIGN
4.1 CHECK CODE 22
4.2 DEFLECTION CHECK 29
5. MEMBER TAKE OFF 31
ATTACHMENT
ATTACHMENT 1 STAAD INPUT MODEL ATTACHMENT 2 STAAD OUTPUT ANALYSIS
1.1. SCOPE
This calculation sheet is purposed to describe design of structure as a part of bulk material handling system in MOPP FeNi-1 Project PT. Aneka Tambang, Pomalaa, Sulawesi Tenggara.
1.2. CODE AND STANDARD
1.2.1. Uniform Building Code, UBC 1997
1.2.2. Minimum Design Loads for Building and Other Structures - ASCE 7-02 1.2.3. Pedoman Perencanaan Bangunan Baja untuk Gedung, SNI 03-1729 – 2002 1.2.4. Structural Welding Code – AWS D.1.1 - 1998 Edition
1.2.5. American Institute of Steel Construction, AISC 360-05 1.2.6. American Society for Testing and Materials, ASTM 1.2.7. American Railway Engineering Association, AREA 1.2.8. Steel Structure Painting Council, SSPC
1.3. REFERENCES
1.3.1. PBA–SP–50–001–A4 Structure Design Specification
1.3.2. PBA–SP–50–005–A4 Fabrication and Construction of Steel Structure Specification
1.4. BASIC DESIGN 1.4.1 Material
a. Steel Structure : JIS SS400 minimum fy = 245 MPa minimum fu = 400 Mpa
b. Structural bolt : High strength bolt ASTM A-325 & BS 1367 Gr.8.8 shear strength Fvb = 1470 kg/cm2
tension capacity Ftb = 3090 kg/cm2 c. Anchor Bolt : ASTM A-307
1.4.2 LOADING DATA
Loading data shall refer to PBA–SP–50–001–A4 Structure Design Specificationdocument.
1.4.3 LOADING COMBINATION
Load combination for steel structure with ultimate design Primary Load
Load 1 Seismic Load in X-axis direction (SX) Load 2 Seismic Load in Z-axis direction (SZ) Load 3 Self Weight (included as dead load) Load 4 Dead Load (D)
Load 5 Live Load (L)
Load 6 Wind Load in Z-axis direction (WZ) Load Combination based on ASCE 7-02 Comb 1 D
Comb 2 D+L Comb 3 D+0.75L Comb 4 D+W
Comb 5 D+0.75L+0.75WZ Comb 6 0.6D+W
Comb 7 D+0.7S
Comb 8 D+0.75L+0.525S Comb 9 0.6D+0.7S
2.1 3D STRUCTURAL MODEL
Structure is modelled as 3D steel frame structure with fixed support at longitudinal direction and pinned support at transversal direction on trestle base while connection between gallery and trestle is fixed connection at transversal direction and simply supported (pinned) longitudinally.
(a)
(b)
Fig 2.1 3D Model Design in STAAD PRO Program Analysis (a) 3D (b) longitudinal section
2.2 LONGITUDINAL AND TRANSVERSAL SECTION
In longitudinal direction, structural members are designed to fully utilize its material strength by using fixed connection to join bottom chord, shear web, and top chord. In transversal section, structural member are joined with high strength bolt connection as shear and truss member.
Fig 2.2 Longitudinal and transversal section in STAAD PRO Program Analysis
2.3 LOADING APPLIED IN STRUCTURE MODEL
Steel truss gallery will be subjected to equipments and bulk material weight. Nodal loads at top chord steel are considered as uniform load subjected along the span. Based on preliminary design, gravitational load governs steel truss gallery design.
Fig. 2.3 Uniform Load is applied at top chord of steel truss conveyor gallery
(a) (b)
Fig. 2.4 (a) Wind pressure as uniform load is applied at trestle & gallery cross section (b) Earth quake load is subjected as nodal load at highest point of trestle.
Fig. 2.5 Single segment 6 meters-long of steel truss gallery structure
WZ
EZ
3. EXTERNAL LOADING CALCULATION 3.1 DEAD LOAD (D)
Dead loads are the self weight of structures or foundations and all permanent facilities, such as floor, roof, joist, stairways, etc.
3.1.1. Structure Self-weight
The Dead Load is the load of the structure itself (calculated by STAAD-PRO). with command "Selfweight Y-1.0", and other dead load as describes below.
3.1.2. Equipment Load
conveyor belt = 0,29 kN/ 30 kg/m
Frame = 0,27 kN/ 28 kg/m
Idler (carry) = 0,33 kN/ 34 kg/m
Idler (return) = 0,25 kN/ 26 kg/m
corrugated sheet belt cover 4 kg/m2 x 1 m = 0,04 kN/ 4 kg/m
pipe = 0,16 kN/ 16 kg/m
total equipment load (exc.
Pipe) = 1,20 kN/
subjected to idler
supports = 0,60 kN/
3.1.3. Walkway Platform
Platform Area Load span 0.8 m = 0,08 kN/ 19, kg/
Handrail at 1.5 m interval = 0,10 kN/
10 kg/m
cable tray 1 = 0,30 kN/
30 kg/m
Fig. 3.1 Dead Load (a) uniformly distributed force along top chord member (b) nodal load at walkway
3.2 LIVE LOAD (L)
3.2.1. Ore/Bulk Material Load
bulk material on conveyor = 2,35 kN/
m2 24
0 kg/
m2 belt width 1 m x 2.35 kN/m2 = 2,35 kN/m
subjected to idler supports = 1,18 kN/m 3.2.2. Walkway Live Load
Inspection
Platform = 0,98
kN/
m2
10 0
kg/
m2 subjected at 100 kg/m2 x 0.8
m span = 0,80 kN/m 80 kg/m
Fig. 3.2 Liveload uniformly distributed along top chord member along with nodal load for walkway
3.3 EARTHQUAKE LOAD (E)
Seismic load will be calculated by staadpro automatically with dynamic analysis.
Seismic load design is depend on natural period and ductility factor of the structure.
Design spectral = Spectral acceleration / R
R (structural system factor) = 4.5 (ordinary moment resisting ftrame) Importance factor = 1
Design response spectra for return period 500 years.
Dead Load (Self-weight + permanen equipment load) is used for seimic load calculation
Seismic Load is calculated based on
V = C
vI W R T
Rx = 4.5 (Ordinary moment resisting frame) Rz = 4.5 (Ordinary moment resisting frame) 3.3.1 Soil Properties
Based on soil investigation on site, Soil profile types on which conveyor structure is sat on is considered as stiff soil - SD (Soil Profile Types – UBC 1997-Table 16-J). Based on this category, Seismic coefficient Ca and Cv can be determined as follows :
Zone 3, SD soil profile type Ca = 0.36
Cv = 0.84 3.3.2 Self-Weight
Structure self-weight for conveyor structure is calculated on STAAD Pro “self-weight” command.
Table 3.1 Maximum Dead Load Support Reaction
Table 3.2 Maximum Dead Load Support Reaction for convetor side without walkway 3.3.3 Structure Natural Periode
Based on UBC 1997, steel moment resisting frame can be determined with T=Ct(hn)3/4 Where,
Ct = 0.0853
Hn = structure height (meter) T = Tx = Tz = 0.0853 x (12)3/4 = 0,549 s
3.3.4 Base Shear Force
Transversal Seismic Load (connection between gallery and trestle) Total base shear for seismic load calculation, for W = 27.840 kN
V = C
vI W R T =
0.84
x1
x27.840
4.5
x0.549
=9.465
kNMaximum total base shear
V = 2.5 C
aI W
R
=2.5
x0.36
x1
x27.840
4.5
=5.568
kNMaximum base shear value will be used for seismic load at transversal direction at node 450 SZ = 5.568 kN
Transversal Seismic Load (connection between gallery and trestle) Total base shear for seismic load calculation at node 965, W = 19.261 kN
V = C
vI W R T =
0.84
x1
x19.261
4.5
x0.549
=6.548
kNMaximum total base shear
V = 2.5 C
aI W
R
=2.5
x0.36
x1
x19.261
4.5
=3.852
kNMaximum base shear value will be used for seismic load at transversal direction at node 973 SZ = 3.852 kN
3.4 WIND LOAD (W)
Wind loads shall be generally as ASCE 7-05 Building category = III Exposure C
V = 68,351 mph 110 km/h
Basic wind speed
I = 1 Importance
factor
Kz = 1.005 10.21 m (see table 3.1)
Kd = 0,85
lattice
framework (see table 3.2) qz = 0.00256*Kz*Kd*(V*I)2
= 10.14 lb/ft2
= 0,489 kN/m2
Gust factor G = 0,85
Structure Properties
Longitudinal dimension = 24 m Transversal dimension = 2,6 m
Height = 10.21 m
Table 3.3 Kz coefficient based in structure height and exposure 9
8 8
6 7
5 5
1 4
Transversal direction
Longitudinal direction
wit h
z = 33.497 ft
zg = 900 ft
α = 9,5
Kz
= 1.00532
Table 3.4 Kd Coefficient based on structure type
Table 3.5 product of internal pressure coefficient and gust effect factor
Table 3.6 Wall pressure coefficient
Table 3.7 Roof pressure coefficient
Transversal direction
L/B = 0,144 h/L = 12.884
Fig 3.5 Wind Load applied to structural
contact surface directio Cp n
cod e windwar
d 1 0,8
roof 2=3 -1,3 leeward 4 -0,5 side
wall 5 -0,7
Table 3.8 Wind direction coefficient
F = Af*(qz*G*Cp)
wind trib. area GCp qz Fz
direct Af (m) kN/m
1 1.5 0.68 0.489 0.50
trestle
1 0.5 0.68 0.489 0.17
4 1.5 -0.425 0.489 -0.31
trestle
4 0.5 -0.425 0.489 -0.10
2=3 1.5 -1.105 0.489 -0.81
5 0.65 -0.595 0.489 -0.19
Table 3.9 Wind Force on Gallery Structure
4. MEMBER DESIGN
Steel profile selection is done by limitting unity ratio to 1. However, there are practical considerations involved in steel profile selection. Main members are mainly consist of angle and UNP steel profile which are used as bottom chord and top chord respectively. Equal angle is also chosen for shear web and lateral bracing.
4.1 CHECK CODE BASED ON AISC ASD FOR UNITY RATIO 4.1.1. BOTTOM CHORD UNITY RATIO
Table 4.1 Bottom Chord Unity Ratio Maximum unity ratio for top chord is 0.871 < 1 OK!
4.1.2. TOP CHORD UNITY RATIO
Table 4.2 Bottom Chord Unity Ratio Maximum unity ratio for top chord is 0.613 < 1 OK!
4.1.3. VERTICAL SHEAR WEB UNITY RATIO
Table 4.3 Shear Web Unity Ratio Maximum unity ratio for shear web is 0.962 < 1 OK!
Table 4.4 Diagonal Shear Web Unity Ratio Maximum unity ratio for shear web is 0.426 < 1 OK!
4.1.5. TRESTLE COLUMN
Table 4.5 Trestle Column Unity Ratio
Maximum unity ratio for shear web is 0.600 < 1 OK!
Table 4.6 Trestle Bracing Unity Ratio Maximum unity ratio for shear web is 0.587 < 1 OK!
4.2 DEFLECTION CHECK 4.2.1. Vertical Deflection
Allowable vertical deflection shall be less than L/240
Fig 4.1 Vertical deflection at top chord member
Fig 4.2 Vertical deflection at bottom chord member
Maximum deflection on main member (bottom chor and top chord) is 8.780 mm which is below allowable vertical deflection. Based on this value, it can be concluded that conveyor steel structure has adequate stiffness and strength capacity to withstand gravitational load.
4.2.2 Lateral Drift
Maximum lateral drift shall be less than H/200 where H is height of structure or in particular case such as conveyor trestle, H is defined as distance between base plate top surface and joint between gallery and trestle. Conveyor structure T-1022drift is calculated at +10.21 elevation.
Thus, allowable lateral drift of the structure is H/200 = 10528 mm/200 = 52.64 mm
According to Table 4.7 maximum lateral drift in Z axis is 19.312 mm < 52.64 mm OK!
In X axis direction or longitudinal section, maximum longitudinal deflection is 13.278 mm < 52.64 mm OK!
This longitudinal deflection doesn’t represent proportional structure behaviour because at start and end point of conveyor, the structures are tied in transfer tower with pinned and rolled support respectively.
However, lateral deflection in longitudinal direction shall be less than 2 span 12 meters model.
5. MEMBER TAKE OFF
Based on steel membes take off for 12 m span including gallery and trestle, rate of steel material requirement for main member is 162.989 kg/m.
Table 4.8 Conveyor structure Member Take Off
