Transcript
ANALYSIS OF EXISTING STRUCTURES
Self Supporting Tower 120 m Height
Prepared By;Jemi Dwi Astomo, ST
STANDARD/REFERENCETIA/EIA -222-F 1996 STANDARD
Structural Standards for Steel Antenna Towers and Antenna Supporting Structures
AISC-LRFD’99 Manual of Steel Construction
ACI-318 -99 Building Code Requirement For Structural Concrete
ASCE 7-98 Minimum Design Load For Building and Other Structures
CRITERIA FOR THE ANALYSIS OF EXISTING STRUCTURES
According to TIA/EIA -222-FStructural Standards for Steel Antenna
Towers and Antenna Supporting Structures
CRITERIA FOR THE ANALYSIS OF EXISTING CRITERIA FOR THE ANALYSIS OF EXISTING CRITERIA FOR THE ANALYSIS OF EXISTING STRUCTURESSTRUCTURESSTRUCTURES
There is change in antennas, transmission
lines, and /or appurtenances ( quantity, size,
location or type )
There is a change in Operational Requirements
( Twist and Sway )
There is need to increase wind speed to load
scale for safety ratio
When Structural Tower Structures Should be Reanalysis ?
CRITERIA FOR THE ANALYSIS OF EXISTING CRITERIA FOR THE ANALYSIS OF EXISTING CRITERIA FOR THE ANALYSIS OF EXISTING STRUCTURESSTRUCTURESSTRUCTURES
Member Size, Dimension, and Connection
Material Properties
Existing and Proposed loading ; antennas (size,
elevation, and azimuth), and Appurtenances.
To Perform the Analysis, The Following data is Required !
CRITERIA FOR THE ANALYSIS OF EXISTING CRITERIA FOR THE ANALYSIS OF EXISTING CRITERIA FOR THE ANALYSIS OF EXISTING STRUCTURESSTRUCTURESSTRUCTURES
Previous Stress and Rigidity analysis ( Structure and
Foundation )
Structural and detail drawing ( design and as-built )
Specifications
Construction Records
Field Investigation
Data may be obtained from the following sources ;
TECHNICAL SPECIFICATION OF EXISTING STRUCTURES
According to construction records SST 120 m - Height
TECHNICAL SPECIFICATION OF TOWERTECHNICAL SPECIFICATION OF TOWERTECHNICAL SPECIFICATION OF TOWER
Steel Structures SS-400 ( Fy = 2400 kg/cm2 )
Bolt & Nut JIS grade 8.8 (Fy= 5500 kg/cm2 )
Anchor Bolt ASTM A-307 ( Fy= 2400 kg/cm2 )
First Coating Hot Dip Galvanizing ASTM A-123
Welding Electrodes AWS D1.1 E60XX
Concrete K-225 ( Fc’=19 Mpa ) 28 days
Rebar Grade Fy= 240 < 12 mm ( BJTP )
Fy= 320 > 13 mm ( BJTD )
Materials
LOADING FOR THE ANALYSIS OF EXISTING STRUCTURES
According to TIA/EIA -222-FStructural Standards for Steel Antenna
Towers and Antenna Supporting Structures
LOADING OF TOWER STRUCTURELOADING OF TOWER STRUCTURELOADING OF TOWER STRUCTURE
LOADING OF TOWER STRUCTURELOADING OF TOWER STRUCTURELOADING OF TOWER STRUCTURE
Dead Load – The weight of the Structure and Appurtenance
Wind Load – The Horizontal force applied to the structures in
the direction of wind .
F= qz . GH [CF . AE+Σ(CA . AA)]
Antenna Load
Fa= CA . Kz.GH.V2
Fs= Cs . Kz.GH.V2
M= Cm . Kz.D.GH.V2
Seismic Load
Vertical and Horisontal Loading
LOADING OF TOWER STRUCTURELOADING OF TOWER STRUCTURELOADING OF TOWER STRUCTUREAntenna Load ( MW/Parabolic , GSM )
LOADING OF TOWER STRUCTURELOADING OF TOWER STRUCTURELOADING OF TOWER STRUCTUREAntenna Load ( MW/Parabolic , GSM )
REVIEW FOR THE ANALYSIS OF EXISTING STRUCTURES
According to TIA/EIA -222-FStructural Standards for Steel Antenna Towers and Antenna Supporting
AISC-LRFD’99
REVIEW FOR ANALYSIS TOWER STRUCTUREREVIEW FOR ANALYSIS TOWER STRUCTUREREVIEW FOR ANALYSIS TOWER STRUCTURE
Σ λi.Qi < φ Rn ( Member Checking By SAP
2000)
Stress
Slenderness Ratio
L/r < 150 For Legs member
L/r < 200 For Bracing member
L/r < 250 For Redundants member
REVIEW FOR ANALYSIS TOWER STRUCTUREREVIEW FOR ANALYSIS TOWER STRUCTUREREVIEW FOR ANALYSIS TOWER STRUCTURE
The angular rotation of the antenna beam path in a
Vertical plane
Sway
Twist
The angular rotation of the antenna beam path in a
Horizontal plane
REVIEW FOR ANALYSIS TOWER STRUCTUREREVIEW FOR ANALYSIS TOWER STRUCTUREREVIEW FOR ANALYSIS TOWER STRUCTURESway & Twist
FIELD INVESTIGATION OF EXISTING STRUCTURES
According to TIA/EIA -222-FStructural Standards for Steel Antenna
Towers and Antenna Supporting Structures ( Annex E Fig.E6 )
FIELD INVESTIGATIONFIELD INVESTIGATIONFIELD INVESTIGATIONTwist and Plumb Field Investigation
Twist – Angular rotation in horizontal Plane between any two
elevation shall not exceed 0.5 degree in 3 meter and total twist in the
structure shall not exceed 5 degree.
Plumb- The Horizontal distance between the vertical centerlines at
any two elevation shall not exceed 0.25 percent of the vertical distance
between the two elevation .
FIELD INVESTIGATIONFIELD INVESTIGATIONFIELD INVESTIGATIONTwist and Plumb
FIELD INVESTIGATIONFIELD INVESTIGATIONFIELD INVESTIGATION
SOIL INVESTIGATION TESTSONDER TEST
BORING TEST
VERYFICATION LOADINGTIA/EIA -222-F
VsIndonesia Loading code PMI/PPI’83
VERYFICATION LOADINGVERYFICATION LOADINGVERYFICATION LOADING
* see Grafik verify PMI & TIA/EIA-22-F
Discrete Apportunance
Σ(CA.AA)] =F=P.C.AF=qz.GH[CF.AE+Σ(CA.A
A)]DESIGN WIND LOAD6
1.0<GH<1.25
h = height of towerNot ApplicableGH=.65+0.6(h/10)1/7GUST RESPONSE FACTOR5
+1.2 ( behind wind dir.)( Normal Wind Direction )
+1.6 ( front wind dir.)1Wind Direction Factor4
e = Solidity Ratio( 3D Analysis Modeler)
e = ( AF + AR )/AGNot ApplicableCF=4.0 e2-5.9e+4.0STRUCTURE FORCE COEFFICIENTS3
ground level
z = height above
h = height of toweror V2/16
Kz= (z/10)2/7p=42.5+0.6 hKg/m2qz=0.613.KZ.V2 PaVELOCITY PRESSURE *2
120Kph120KPhBASIC WIND SPPEED ( STANDARD SATELINDO )1
7654321
FORMULAUNIT ( SI )FORMULAUNIT ( SI
)REMARKS
PMI/PPI'1983 TIA/EIA-222-FDESCRIPTIONN
O
FORMULA ( WIND FORCE CALCULATION )
VERYFICATION LOADINGVERYFICATION LOADINGVERYFICATION LOADINGVELOCITY PRESSURE
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