20110628 MIDAS Advanced Gen Webinar

midas Gen

midas Gen

Advanced Webinar

Column Shortening for High-rise Building

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Column Shortening for

High-rise Building

Introduction in Column Shortening

Project Applications

Procedure for Construction Stage Analysis

Useful features for Construction Stage Analysis

Demonstration

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Demonstration

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Introduction in

Column Shortening

One Stop Solution for Building and General Structures

4

Introduction

Why construction stage analysis?

Column Shortening

Wind

Live

Earthquake

Completed structure

Live, Wind and Seismic Loads Sequential Loading: Dead Loads

Construction Sequence

Dead

(1) Dead load is sequential load.


5

Introduction


Column Shortening

End Moment of Girder by Stories (Wall Connection)

• Comparison between with and without considering sequential loading

8,000 9,000

4,500 4,500

8,000

9,400

9,400

9,400

3,800

3,800

1,800


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• Column Shortening

– Elastic stresses due to gravity loads

– Creep caused by gravity load

– Drying shrinkage

– Temperature variations of exposed columns

Steel Concrete

ElasticCreep

Shrinkage

19.6--

6.14.66.1

Total 19.6 16.8

Shortenings of an 80-story column (cm)

IntroductionColumn Shortening


(2) Compensation for the differential column shortening in high-rise building


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Effects of column shortening

• Deforms in pipes, elevator rails, cladding• Cracks in partitions


Nonstructural EffectNonstructural Effect

Structural EffectStructural Effect

• Distorted slabs or beams due to differential movements

• Gravity load redistribution


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Shortening related to construction sequence


• Pre-slab installation shortenings– Shortenings of supports that take place up to the time of slab installation

• Post-slab installation shortenings– Shortenings of supports that take place after the time of slab installation

① :Compensation

② : Design Level

③: Pre-slab Installation shortening

④: Post-slab Installation shortening


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Compensation for differential column 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


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Application procedure for column shortening

Application in fieldApplication in field

Material & Section property

Loads, Construction sequence

Pre analysis for column shorteningPre-analysis for column shortening

Considering load redistribution

due to differential shortening

Analysis

• Updating material properties

by experiments

• Construction sequence

considering the field condition

Column Shortening analysis

•Compressive strength

•Modulus of elasticity

•Creep & Shrinkage

Material Experiment

Using Strain gauge

Measuring shortening

• Predicting shortening

for further stages

• Providing an amount of

compensation

Column Column Shortening re-analysis


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Demonstration

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Burj Khalifa (Dubai, UAE)

Column Shortening

Height 705 m

No. of floors 160

Location Dubai, United Arab Emirates

Function / Usage Office Building & Residential Building

Designer Adrian D. Smith

Architect Skidmore, Owings & Merrill

General Contractor Samsung Development

ove

rvie

w


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SK S-Trenue (Seoul, Korea)

Column Shortening

Area 39,600m2

No. of floors 36

Location Seoul, Korea

Function / Usage Office Building

Structure Type Composite Structure

Foundation Type Mat Foundation

Lateral load resisting system RC Core + Steel + RC Composite Frame

ove

rvie

w

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Procedure for

Construction Stage Analysis





Demonstration

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How to use the construction stage analysis in midas Gen

Define materials, sectionsDefine materials, sections

Assign elements, boundaries, & loads to the groups

Assign elements, boundaries, & loads to the groups

Define time dependent materialsDefine time dependent materials

Enter the construction stage analysis dataEnter the construction stage analysis data

Perform an analysisPerform an analysis

Check results for each construction stageCheck results for each construction stage

Check column shorteningCheck column shortening

•Creep & Shrinkage•Compressive strength

Activate/Deactivate element groups / •Specify the duration of CS•Activate/Deactivate element groups / boundary groups/ load groups

Procedure for Construction Stage AnalysisColumn Shortening


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Time Dependent Material Properties

Column Shortening

1. Creep effects of concrete members having different maturities

2. Shrinkage effects of concrete members having different maturities

3. Time dependent compressive strength gain for concrete members


• Creep/Shrinkage

- Eurocode, ACI, CEB-FIP, PCA, India…

• Comp. Strength- Eurocode, ACI, CEB-FIP, Ohzagi , India …

Time dependent material propertiesTime dependent material properties

Construction StageConstruction Stage


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Construction Stage Analysis Data

Column Shortening Procedure for Construction Stage Analysis

0 day 10 day 20 day 30 day 40 day

Construction Stage Duration Construction Stage Duration

Activation or

Deactivation of

element, boundary,

and load

Activation or

Deactivation of load

with time span from

the stage start

Activation or

Deactivation of

element, boundary,

and load


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Check results for each construction stage

Column Shortening Procedure for Construction Stage Analysis

Analysis results can be checked for each construction stage.

Absolute minimum or maximum results of envelope can be also checked among entire construction stages.

Results for creep and shrinkage effect are provided.

[Beam Forces for each construction stage] [Displacement due to Creep & Shrinkage]

CS1

CS3

CS6

CS10

CS12

Min/Max

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Useful Features

for Construction Stage Analysis





Demonstration

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Building Model Generation Wizard

Column Shortening Useful Features for Construction Stage Analysis

The wizard readily allows us to define the timing of elements created and loadings applied in the

construction stages during the erection of a building.

You may find it more convenient to first click the [Automatic Generation] button to define the basic

construction stages and modify them as necessary.


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Construction Stage Analysis for Composite Members


Define an analytical model for each construction stage by assigning activated or inactivated sections

corresponding to each construction stage of a composite section.

By using Composite Section for Construction Stage, we can consider the construction sequence with

creep and shrinkage effect.


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Auto Climbing Formwork System


Construction stage for auto climbing formwork system (ACS) can be generated in midas Gen.


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Tendon Loss


Pre-stress load can be considered in construction stage analysis.

Tendon primary / secondary forces are provided with pre-stress loss graph.

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Demonstration





Demonstration

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One Stop Solution for Building and General StructuresDesign Procedure Demonstration

Example model

Structural plan & section

9@

4=

36m

2@

4.5

=9m

5m

50m

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One Stop Solution for Building and General StructuresDesign Procedure

Section name Section size

G1

G2

G3

G4

WG1

WG2

400x700

400x700

600x800

500x800

400x700

600x800

Story C1 C1A C2 C3 C4

10~12

8~9

6~7

4~5

2~3

1

600x600

800x800

800x1000

1000x1000

1000x1200

1000x1300

500x600

500x600

500x600

600x600

700x700

700x700

600x600

600x800

600x800

800x800

900x1000

1000x1000

600x700

600x800

600x800

800x800

800x800

1000x1000

600x700

600x800

600x800

800x800

900x900

900x900

Section Size and Material Properties

Girder

Column

Wall

Thk = 200

fck = 240 kg/cm2

fck = 280 kg/cm2

fck = 280 kg/cm2

Demonstration

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Construction Schedule

3rd day

1F FormworkInstallation

1F ConcreteCasting


2F ConcreteCasting

1st day 8th day 10th day

3 levels of shoringConstruction cycle time=7 daysTime of removal of lowest level of shores from concreting of top floor=5 days

Age

Age

0 5

0

7

Demonstration

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12

5

15th day

3F ConcreteCasting

7

17th day

0

1F FormworkRemoval


22th day

4F ConcreteCasting

24th day 29th day

2F FormworkRemoval


Age

Age

14

5

12

19

14

21

7

0 5

12

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Demonstration

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Date WorkFormworkRemoval

FormworkInstallation

Conc.Casting

StageDefinition

ProgramDate

StageDuration

1 1F Formwork Installation 1F

3 1F Concrete Casting 1F





22 1F Formwork Removal, 4F Formwork Installation 1F 4Fstage 1

17

24 4F Concrete Casting 4F 3


87



157



227



Demonstration

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Date WorkFormworkRemoval

FormworkInstallation

Conc.Casting

StageDefinition

ProgramDate

StageDuration


297



367



437



507



577


85 10F Formwork Removal 10F stage 10 64 7

92 11F Formwork Removal, 1~3F SDL 11F

stage 11

71

795 4~6F SDL 74

98 7~9F SDL 77

99 12F Formwork Removal 12Fstage 12

787

101 10~12F SDL 80

133 Live Load dummy 112 28


Demonstration

Thank You!Thank You!Thank You!


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Documents

20110628 MIDAS Advanced Gen Webinar