ViaDuct Vibration Analysis Final

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NATIONAL ENGINEERING SERVICES (PVT.) LTD.NESPAK

VIBRATION ANALYSIS OF VIADUCTORANGE LINE METRO RAIL PROJECT

VIBRATION ANALYSIS OFVIADUCTEVALUATION OF EFFECTS ON HERITAGE

BUILDINGS

LAHORE ORANGE LINEMETRO RAIL PROJECT

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NATIONAL ENGINEERING SERVICES (PVT.) LTD. NESPAK

VIBRATION ANALYSIS OF VIADUCTORANGE LINE METRO RAIL PROJECT

TABLE OF CONTENTS

1 INTRODUCTION....................................................................................1

2 FEA MODEL..........................................................................................2

3 VIBRATION EFFECTS HERITAGE BUILDINGS............................................64 CONCLUSIONS......................................................................................8

5 REFERENCES........................................................................................8

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VIBRATION ANALYSIS OF VIADUCTORANGE LINE METRO RAIL

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1 INTRODUCTION

The Viaduct of Lahore Orange line Metro project consists of U-Shaped simply supported girders

resting upon the piers hich are generally !"m apart# The $iaduct system is supported on piles and

pile caps su%structure system# The 1#&'m thic( pile cap consists of ) piles of 1#2m diameter and

piles are 1&m long *for +uger %oring method,# Piers of $iaduct are generally 2!""mm diameters#

The height of piers is generally 1!#'m# + 1"m long transom rests o$er the top of piers to support

the U shaped girders#

Figure 1: Typical Viaduct cross section

The $iaduct %ridge shall carry 1 type trains *according .hinese standards,/ consisting of '

$ehicles# The a0le load of type 1 train is 1"(/ and the a0le load of empty $ehicle is &"(#

3igure 2 %elo shos that train loads4

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Figure 2: Train live Load

.oncerns ha$e %een shon regarding the effects of $i%ration due to passage of train on the

heritage %uildings that e0ist along the Orange line#

3i$e sites ha$e %een identified among the heritage sites listed %elo4-

1# Shalamar 5arden

2# 5ula%i agh6s Tom%

!# uddu6s Tom%

# .ha%urji

'# 7ai% un isa6s Tom%

This document presents the results of $i%ration analysis of Viaduct system due to the passage of

train and its effect on the near%y structures#

2 FEA Model

+ 2-dimensional model is prepared using structural analysis program S+P2"""/ ith the o%jecti$e

of $i%ration time history analysis of the Viaduct# The model consists of pier/ pile cap/ the piles and

surrounding soil# +ll the materials in the model are modelled as elastic materials# The thic(ness of

28 model is (ept as 1m# The out of plane thic(ness of the piles/ pile cap and the pier are

proportioned %ased on the cali%ration of model ith the !8 model of $iaduct# The time period of the

pier in the !8 model is o%ser$ed to %e around 1#1 sec# The out of plane thic(ness of the pier is

adjusted so that the 28 model pro$ided similar fundamental time period *1#29 sec for 28 model,#

Since the soil is modelled as an elastic material *a $ery simplifying assumption,/ the model had to

%e cali%rated to the !8 model for similar $ertical deformations# The modulus of elasticity of the soil

material is adjusted so that the $ertical deflection of !#& mm that is o%ser$ed in the !8 $iaduct

model is o%tained from the 28 model# The model as cali%rated at modulus of elasticity of

2"""MPa for soil for hich the $ertical deflection under the pier is determined as mm# 3igure !

shos the 28 S+P2""" model# The surface nodes are la%elled here the response time histories

are o%tained from the 3:+ analysis#

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Figure 3: 2D FEA Model of Viaduct and surrounding soil system

The $ertical force time history at the top of pier is determined from the dynamic train model of Xia

at el 2001# The dynamic model of train used is presented in figure #

The model is %ased on the principle of modal superposition and the deflection at any section can

%e e0pressed as

Zb(x )

=n=1

n

qnn (x )

;n hich the nth modal e


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Figure %: Load &istory on pier !y moving train o!tained from "ia's (2$$1) model

The force time history is su%jected to the top of the pier# The results of the acceleration/ $elocity

and displacement at the node !9/ *in 3ig 2/ node o$er pile cap, are presented in figure ) to &

%elo#

Figure *: +esponse Acceleration Time ,istory at -ode 3. (at pile cap)

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Figure .: +esponse Velocity Time ,istory at -ode 3. (at pile cap)

Figure /: +esponse Displacement Time ,istory at -ode 3. (at pile cap)

The response of other nodes is similar %ut magnitudes are different# The 3igure = shos the

$ariation of acceleration and $elocity response ith respect to distance from the pier#

Figure 0: Attenuation of acceleration and velocity it& distance aay from viaduct pier

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3 VIBRATION EFFECTS HERITAGE BUILDINGS

>ith reference to the letter su%ject ?.onstruction of Orange line metro train Ser$ice @

;mplementation of +nti


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Figure 12: range Line alignment near 5udd&'s Tom!

Figure 13: range Line alignment near 6&u!ur7i Monument

Figure 1: range Line alignment near 8ai! un -isa Tom!

+ccording to the 5erman Standard 8; 1'" Part !-1=== ?AStructural Vi%ration in uildingsA/ the

ma0imum $i%ration $elocity at the foundation le$el of the heritage structure shall %e less than

!mmBsec# Ma0imum acceleration le$els of "#""' mBs2 are generally considered accepta%le for

human comfort during night#

Ta%le 1 %elo summariCe the findings for effects of $i%rations on Daritage %uildings

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Ta!le 1: T&eoretical Vi!ration magnitude and afe limits according to D9- 1%$ standard

Heritae Site Di!ta"#e $r%&Pier

Pea' e%#it*at !ite +&&,!-

Sa$e Li&it! a!

er DIN /012

!ta"3ar3

S4aa&ar Gar3e" 2= E"#"1

E!mmBsforDeritageSites

G5a6i Ba47! T%&6 21 "#")

B53357! T%&6 1 "#"&

C4a65r8i 1) "#12

9ai6 5" Ni!a7! T%&6 !!#' E"#"1

4 CONCLUSIONS

The locations of fi$e heritage sites along Metro Orange Line are analysed for the $i%rations induced

%y the passage of train o$er the Viaduct %ridge# ased on 3:+ modal $i%ration analysis of the

Viaduct/ it is concluded that the $i%rations are ithin the limits set up for Deritage sites according to

international standards#

5 Referene!

5erman Standard 8; 1'" Part !-1=== ?Structural Vi%ration in uildings @ :ffects on

StructureA

F;+# D/ 7D+5 #/ ?Vi%ration :ffects Of Light Gail Train Viaduct System on Surrounding

:n$ironmentsA Proceedings of the :astern +sia Society for Transportation Studies/ Vol#!/

o#!/ Octo%er/ 2""1#

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