Vertical Shortening and Health Monitoring of Lotte World TowerCase Study

7/28/2019 Vertical Shortening and Health Monitoring of Lotte World TowerCase Study

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Vertical Shortening &Structural Health

Monitoring of

Lotte World Tower 3rd April 2013


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Contents

I. Introduction

II. Vertical Shortening of Lotte World Tower

III. Structural Health Monitoring of Lotte World Tower


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Contents

I. IntroductionII. Vertical Shortening of Lotte World Tower



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Construction Stage Analysis

Why Construction Stage Analysis

In general structures are analyzed assuming that the structure is built and loaded in a moment.

Construction of structures is a time taking process and during this period Material Properties, Loads and

Boundaries conditions may change.

Construction Sequence

Self weight of slab

Other Dead Loads (Partions, Finishes)

Completed Structure

Dead Load + Live Load

Wind

Earthquake

LL,WL,EQActs


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Construction Stage Analysis

Why Construction Stage Analysis

In general structures are analyzed assuming that the structure is built and loaded in a moment.

Construction of structures is a time taking process and during this period Material Properties, Loads and

Boundaries conditions may change.

End Moment of Girder by Stories (Wall Connection)


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Column Shortening & Related Issues

The behavior of concrete structures are typically determined using Linear elastic analysis and/or summation of vertical column loads.

With the increase in building height the actual behavior of the structure increasingly diverges from the results of such conventional analysis.

Long-term, time-dependent deformations in response to the construction sequence, creep and shrinkage canredistribute the forces and gravity induced side sway that would not be detected by conventional methods.

When the time dependent effects of construction, creep, shrinkage, variation of concrete stiffness with time,sequential loading are not considered the predicted forces and deflections may be inaccurate.

With increased height of structures the effect of column shortening (Elastic & Inelastic) take on added significanceand need special consideration in design and construction.

The strains in the columns of low as well as ultra-high rise buildings are similar if the stress levels are similar;however, the overall column shortening is cumulative and depends upon the height of the structure.

Elastic Shortening of 80 Storey Steel Structure ~ 180 mm to 255 mm.

Elastic Shortening of 80 Storey Concrete Structure ~ 65 mm.

Total Shortening of 80 Storey Concrete Structure ~ 180 to 230 mm.

Inelastic Shortening ~ 1 to 3 times Elastic shortening.


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Steel Structures

- Linear elastic Behavior

Stress StrainStrain is constant for a given Stressduring loading & unloading

E = ( / )

L = (PL/A E)

Concrete Structures- Nonlinear Inelastic Behavior

- But in general Analysis and design behavior of concrete is treated as linear elastic material

Neither Stress StrainNor Strain is constant for a given StressDuring loading & unloading

Elastic Strain + Inelastic Strain


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Concrete Structures

Elastic Shortening

Modulus of Elasticity changes with time .

E i = ( / )

L = (PL/A E i)

Inelastic Shortening

Creep Shortening.Shrinkage Shortening.


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Effects of Column Shortening

Absolute shortening is rarely of practical interest.

Differential shortening between adjacent vertical elements is the most important factor for engineer.

Axial Shortening of vertical elements will not effect those elements very much, horizontal elements like beams and slabs and non

structural elements are affected.

Slabs may not be truly horizontal after some time.

Beams could be subjected to higher bending moments.Load transfer.

Structural Effects

Cracks in Partition Walls.Cracks in StaircasesDeformation of Cladding.

Mechanical Equipment. Architectural Finishes.Built in Furnishings.

Non Structural Effects


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Effects of Column Shortening

Deformation and breakage of Facades, windows &Parapet walls

Reverse Inclination of Drainage Piping System

Deformation of Vertical Piping System Deformation and breakage of internal partitions


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Procedure for Accounting

Two basic prerequisites for accurately and efficiently predicting these effectsare

Reliable Data for the creep and shrinkage characteristics of the particular concrete mix Analytical procedures for the inclusion of these time effects in the design of structure.

Some of the popular predictive methods for predicting creep and shrinkage

strains are

ACI 209 -92Bazant Bewaja B3CEB FIP (1978, 1990)PCA Method (Mark Fintel, S.K.Ghosh & Hal Iyengar)

GL 2000 (Gardner and Lockman)Eurocode

C


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C


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0.0E+00

5.0E-05

1.0E-04

1.5E-04

2.0E-04

2.5E-04

3.0E-04

3.5E-04

4.0E-04

4.5E-04

5.0E-04

0 50 100 150 200 250 300 350 400 450 500 550Date

S t r a i n

Back Analysis Output(TA1-20F-02)

Stain Gauge Output(TA1-20F-02)

Reflection of physical properties in calculation frommaterial experiment:

Youngs Modulus, Poissons Ratio, MeanCompressive strength, Volume to Surface ratio,Shapes, sizes etc.

Reflection of effects of Climate on shortening: Average Temperature , RH etc.

Construction Sequence:

Stage duration, Additional Steps, Member Age, Load activation age, Boundary activation age etc.

Reflection of the above effects on site master-schedule

Installation of sensors or gages in members for determining the actual shortening.

Understanding and noting the following:Curing procedure / Temperature,

Actual Shortening,Change in Ambient Temperature (Important),

Actual Humidity,Deviation from Defined Construction Stages,

Manipulation of factors in analytical Calculation,Re- Analysis

Deferent between analysis v alue and measurement

Analytical Measurement Experimental Measurement

Using Software or Manually(Manual calculation is almost impossible) Field Measurements

C


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Field Measurements

Determination of Installation location Installation of Gauge After Installation

After Installation of Gauge After Casting of Concrete Field data collection

C


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Compensation at Site

Pre-slab installation shortenings

Shortenings taking place up to the time of slab installation

Post-slab installation shortenings

Shortenings taking place after the time of slab installation

:Compensation

: Design Level

: Pre-slab Installation shortening

: Post-slab Installation shortening

Reinforced Concrete Structure

Pre-slab installation shortenings has no importance

Compensation by leveling the forms

Post-slab installation shortenings due to subsequent loads and creep/shrinkage

Steel Structure

Columns are fabricated to exact length.

Attachments to support the slabs

Pre-slab installation shortenings need to be known.

Compensation for the summation of Pre-installation and Post-installation shortenings

C


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ColumnColumn

1 st correction

2nd correction

1st correction

C


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SLAB THK.

B (= Height ofcorrection

filler

Height of correction

Column Rebar

CON'C Casting face The order of construction

installation of column forms

insertion of FILLER

insertion of correcting FILLER

Installation of SLAB forms

securing the thickness of slab.

C


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I. Introduction

II. Vertical Shortening of Lotte World Tower


C O i


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Overview

C O i


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Overview

Location Jamsil, Seoul, South Korea.

Height Roof 554.6 m; Antenna Spire 556 m

No. of Floors 123

Floor Area 304,081 m 2

Function / Usage Office, Residential, Hotel, Observation Deck

Structure Type Reinforced Concrete + Steel

Lateral load resisting system Core Wall + Outrigger Truss + Belt Truss

Foundation Type Mat Foundation

Construction Period March 2011 ~ 2015

Lotte World Tower

C Overview


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Overview

Location Jamsil, Seoul, South Korea.

Height Roof 554.6 m; Antenna Spire 556 m

No. of Floors 123

Floor Area 304,081 m 2

Function / Usage Office, Residential, Hotel, Observation Deck

Structure Type Reinforced Concrete + Steel

Lateral load resisting system Core Wall + Outrigger Truss + Belt Truss

Foundation Type Mat Foundation

Construction Period March 2011 ~ 2015

Lotte World Tower

C Overview


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Overview

1 1

2

Initial Curing

Concrete Structures deformation = = Elastic Strain 1 + Inelastic Strain 2

Inelastic Shortening ~ 1 to 3 times Elastic shortening.

Conc

Vertical

Member

Pre-slab Installation shortening

Core wall Column

CoreShortening Column

Shortening

< Deferential Deformation >

Deferential Shortening

General Height 555m / 123 floors

Tower Deformati

on

Deformation of the tower is a naturally occurring depending on material, constructionmethod

Vertical Deformation:Vertical Shortening / Settlement / Construction Errors

Horizontal Deformation:Differential Shortening / SettlementUneven load due to construction method

Asymmetric floor plan / Construction errors

Horizontal Deformation

VerticalDeformation

WithTime

C Vertical Shortening and Related Issue


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Vertical Shortening and Related Issue

High-rise Considerations

Wind Induced

acceleration control

Optimum StructureSystem

Construction Jointmanagement

Lateral-Displacement

control

Concrete PumpingTechnology

Health Monitoring

ShorteningPredictionTechnology

High performanceConcrete Spalling

Structural safety aspects Usability aspects

Cost increase due to Mega columns,outrigger additional stress

Safety concerns, accordingto the tilt of the tower

Absence of a connectionbetween tower and parking lotcause safety issue

Deformation of Material occursdue to Additional stress

Safety problems of unequal deformationcaused by the slab structure at the hotelarea

Elevators safety due to towers tilt

Curtain wall and exterior materialsdeformation and failure occurs

Deformation of Vertical pipingand breakage problems

Reverse Inclination of Drainage Piping System

Inconvenience to residents mayoccurs due to the slope of the slab

Defection problem due tobreakage of finishes

Deformation of VerticalPiping System

Elevators safety due totowers tiltAdditional Stress of Outrigger

C ShorteningReviewProcess


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Shortening Review Process

Preliminary Analysis

Material / Section Properties

Applied Load, Schedule

Main analysis

Updating material properties from experiments

Construction sequence considering the fieldcondition

1st, 2nd, 3rd Re-Analysis

Suggestion of compensation and details for non-constructed part of structure

Final Report

Shortening, result from test, measurement Review

Material Experiment

Compressive strength

Modulus of elasticity

Creep & Shrinkage

Measurement

Measurement of strain for Column & Wall

Design with AdditionalForce

ApplyingCompensation to in-situ

structure

Design

Const-ruction

0.0E+00

1.0E-04

2.0E-04

3.0E-04

4.0E-04

0 5 0 1 00 1 50 2 00 2 50 3 00 3 50

S t r a

i n

Day

Back Analysis Output (103-1F-01)

Strain GaugeOutput(103-1F-01)

C Pre-Analysis - Deformations


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Pre-Analysis - Deformations

Vertical deformation

Deferential Shortening

Horizontal deformation

Differential settlement

Deferential shortening btw Core & Column

Steel column: Max 18mm

Mega column: Max 65mm

Top of tower Steel Frame: 368.7 mm Core wall: 314.0 mm

Top of mega column

Mega Col: 297.8 mm Core wall: 241.3 mm

ABOVEFIRESHUTTER

ABOVE ABOVEFIRESHUTTER

ABOVE

X-Dir

Y - D i r

OW1OW2

OW9OW8

O W 1 1

O W 1 2

OW10

OW3OW4

O W 5

O W 6

O W 7

O W 1 0

O W 1

O W 4

OW7

Pridiction

X dir: 27.2mmY dir: 115.5mm

Safety check

Elevators rails

Vertical Pipes

X

Y

MEGACOL. CORE WALL

FOUNDATION

MEGACOL.

MEGACOL. CORE WALL

FOUNDATION

MEGACOL.

Core wall settlement: 35mmColumn settlement: 16mm

Core wall Column

CoreShortening

ColumnShortening

DeferentialShortening

Lantern & Core

C Pre-Analysis - Stresses


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Pre Analysis Stresses

Outriggers additional stressSlabs additional stress

Podiums additional stress

Differential Deformation btw Slab-Column

Slab has additional stress

Additional stress btwtower & podium

Max 100 ton.m

Require SettlementJoint & Safety check

Additional Stress without Delay Joint

1 st outrigger (L39~L43): 3,600 ton s 2nd outrigger (L72~L75): 4,700 ton s

required a delay joint installation

Additional Stress with Delay Joint

1 st outrigger (L39~L43): 1,700 ton s

2nd outrigger (L72~L75): 2,000 ton s

PodiumTower

connection

L87~L103

L72~L75

L39~L43

B06~B01

C Pre-Analysis Compensation


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Pre Analysis Compensation- Core wall: Absolute correction for securing design level

- Column: Relative correction for deferential shortening

Relative correction between core and column

correction due to measurement

pre-Analysis

Analysis

Re-analysis1~6 times

MaterialTest

Measurement

1 st correction

2nd correction

Additionalcorrection for unconstructed

L106~L123 + 1m m

L76~L105 + 2m m

L72~L75 +3m m +2 5m m 2nd O /R

L69~L71 + 3m m + 30 m m

L66~L68 + 3m m + 35 m m

L63~L65 + 2m m + 40 m m

L60~L62 + 2m m + 45 m m

L57~L59 + 2m m + 50 m m

L54~L56 + 3m m + 55 m m

L37~L53 +3 m m +6 0m m 1st O /R

L34~L36 + 3m m + 55 m m

L31~L33 + 3m m + 50 m m

L28~L30 + 3m m + 50 m m

L25~L27 + 3m m + 45 m m

L22~L24 + 3m m + 40 m m

L19~L21 + 3m m + 35 m m

L16~L18 + 3m m + 30 m m

L13~L15 + 3m m + 25 m m

L10~L12 + 3m m + 20 m m

L7~L9 + 3m m + 15 m m

L4~L6 + 3m m + 10 m m

B6~L3 + 3m m + 5m mB06

L01

L40

L20

L10

L30

L50

L60

L70

L80

L90

L100

L110

L120

TOP

2nd O/R

1 st O/R

Lantern

1 st B/T

2nd B/T

Floor Core Column

L106-L123 Design level+1mm Steel columns

L76-L105 Design level+2mm Steel columns

L72-L75 Design level+2mm Core level+25mm






L37-L56 Design level+3mm Core level+55mmL54-L56 Core level+60mm












B6-L3 Design level+3mm Core level+5mm

C Material Testing


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Loading of Specimens

Material TestingMatertial Testing ( Construction Materials, Chungnam National University Engineering Laboratory)

Specimenscreated

Curing

Testing

CREEP

Strain Gauge Attachment

Strain Gauge

2 years

Drying Shrinkage Elastic Modulus

Primary Modulus test

Secondary Modulus test

Third order Modulustest

Measure

DeformationMeasure

Deformation

2 Years

Final Report

Compressive strength / modulus of elasticity / drying shrinkage / creep experiments.

Generate formulations based on the test and update the model

Need on-site materials testing according to the construction progress

to reflect Site Conditions at a given time

Compressive strength of 80, 70, 60MPa concrete.

Chungnam National Laboratory (Period: 2011.01 ~2013.01)

C Material Testing


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0

2

4

6

8

10

12

14

16

18

20 30 40 50 60 70 80 90 100 110 120

( x 1 0 3

)

28

(PCA)

Measured vs Analytical

1) The case of a pre-interpretation(Analysis) is proceed based on assumptions about the

processes, materials, and environmental.

Safety review reflected as a result of conservative

Pre-analysis results reflect only the correction due to usability degradation concerns

2) Therefore, material test/ measurement / analysis step are suggested to perfome

shorten process of project

3) In the step of Construction, compensated during construction and verification neededthrough service company

ShorteningFactor Property

Loading

Environment Elastic Modulus /Concrete Strength Water Cement ratio Aggregate Characteristics Degrees of Compaction

Schedule change Design load vs Construction load Construction error Differential settlement in foundation

Temperature Relative humidity

(30~40%)

(15~25%)(30~40%)

Error minimization through material testingperformed

Measurement/Analysis in the future througherror correction

C Vertical Shortening Measurement


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g

0.0E+00

5.0E-05

1.0E-04

1.5E-04

2.0E-04

2.5E-04

3.0E-04

3.5E-04

4.0E-04

4.5E-04

5.0E-04

0 50 100 150 200 250 300 350 400 450 500 550Date

S t r a i n

Back Analysis Output(TA1-20F-02)

Stain Gauge Output(TA1-20F-02)

Analysis Measurement

Reflection of physical properties in calculation frommaterial experiment:

Youngs Modulus, Poissons Ratio, MeanCompressive strength, Volume to Surface ratio,Shapes, sizes etc.

Reflection of effects of Climate on shortening: Average Temperature , RH etc.

Construction Sequence:Stage duration, Additional Steps, Member Age, Load activation age, Boundary activation age etc.

Reflection of the above effects on site master-schedule

Installation of sensors or gages in members for determining the actual shortening.

Understanding and noting the following:Curing procedure / Temperature,

Actual Shortening,Change in Ambient Temperature (Important),

Actual Humidity,Deviation from Defined Construction Stages,

Manipulation of factors in analytical Calculation,Re- Analysis

Deferent between analysis value and measurement value

Deferent between analysis value and measurement

C Vertical Shortening Measurement


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g

B06

L01

L38

L18

L10

L28

L50

L60

L70

L76

L90

B03

Foundation settlement

400 gauges

(30~60 per floor)

ABOVEFIRESHUTTER ABOVE ABOVEFIRESHUTTER ABOVE

: Mega Column

: External Core

: Internal Core

Gauges Location in Plan

Gauges Location of settlement

: Pressure cell

: Level surveying

: Strain Gauge

: B006~L070

A

A-A

: B006~L050

A

C Structural Safety Review


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y

additional stress due to differential shorteningbetween core and column

Reinforcement counter measure by stress exceed

Provides reinforcement due to stress exceed Provide outrigger delay joint provide optimal days if delay Joint require

Effect & Countermeasure due to shortening

1 st Outrigger (L39~L43)

Steel Outrigger Delay Joint

Steel Outrigger Adjustment Joint

(Securing safety under construction)

Outrigger Structural Safety issues and alternatives proposed

2nd

Outrigger (L72~L75)

Additional Stress4700 kN

Additional Stress3660 kN



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additional stress due to differential shorteningbetween core and column

Reinforcement countermeasure by stress exceed

provide Detail of reinforcement in each area


L

Additional Force induced by differential shortening

Slabs additional stress check

STORY 26F~35F

2-HD19

2-HD19

2-HD19

1-HD19

3-HD19

2-HD19

Reinforcement

Example of reinforcement due to additional force

Tower Slab Structural Safety issues and alternatives proposed

Connecting member

Core WallColumn

DifferentialShortening



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Lower Levels Structural Safety issues and alternatives proposed

Moment & Shear force due to phase difference

Phase difference=Diff. shortening + Foundation Dif. settlements- Diff. shortening : difference between columns & podium

- Dif. settlements : difference between podium & foundation

Additional force due to phase difference

Alternative- Structural reinforcement & Control Joint- Settlement Joint


a

b

t

Control Joint

a + b 1/5 to 1/4 t

BEAM &

GIRDER

Jack Support

Settlement Joint

Detail of Control Joint

Detail of reinforcement

Reinforcement for moment

The Side of Podium The Side of Tower

The Side of Podium

The Side of Tower



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Curtain Wall Correction

To prevent damage / elimination of curtain wall due to

differential shortening among columns

To prevent damage / elimination of curtain wall due to Stack

Joint


JointControl

Thermalexpansion

ElasticShortening

InelasticShortening

HORIZONTAL SECTION DETAIL HORIZONTAL SECTION DETAIL(STACK JOINT)

Curtain Wall Stack Joint Plan

Required Stack Joint plan considering vertical shortening value



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Partition Wall Correction

1.0B SOLID BRICK

1.0B SOLID BRICK

T18 MORTAR

T18 MORTAR

THK10 VIBRATIONPROF RUBBER

FIRE SEALANT

Masonry Type Partition Panel Type

: Location of target partition

Column Core

PARTITION

Crack

Column Core

PARTITION

timeelapsed



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Correction for Vertical Piping

Review vertical piping deformation Appropriate deformation absorbing joint details and location

suggests

Review Reverse Inclination due to deferential settlement

Shortening impact and solutions

Expansion Joint

v1

: v = ( v1 + v2 + v3 )

h

v2

v3

Joint: h

vertical pipings joint

< Alternative against deformation >



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Elevator Equipment calibration

Drop of clip position due to Core collapse

Deformation of the elevator rails due to Core collapse

Rails the lower part of the bumper beam

Review in Buffer section require for the lower bumper beam

of rails

Shortening impact and solutions

Derail rail clips due to shortening

Decrease supporting capacity of guide rail

Sliding Clip derailed

Securing 5mm free spacein every floor

Cl


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Vertical Shortening and Health Monitoring of Lotte World TowerCase Study

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