1.Analysis of Existing Structures

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