A Study on the Effective Lateral Drift Control of Super-tall Buildings …C).pdf · 2018-01-08 · A Study on the Effective Lateral Drift Control of Super-tall Buildings in Korea

Steel Structures 6 (2006) 237-246 www.kssc.or.kr

A Study on the Effective Lateral Drift Control of

Super-tall Buildings in Korea

Young-Hak Kim1,* and Sung-Woo Shin2

1Senior Researcher, Research & Development Institute, Lotte Engineering & Construction Co., Ltd., Korea2Professor, Department of Architectural Engineering, Hanyang University and

Chairman, KSTBF (Korea Super-Tall Building Forum), Korea

Abstract

High-rise residential buildings, especially multi-use residential and commercial buildings, have been prospering in Koreasince the late 1990s. Although six of the 200 tallest buildings in the world are in Seoul, no building over 100 stories tall hasyet been constructed. The characteristics of Korean high-rise buildings are as follows: they are located in Seoul City, Sung-nam City, Kyung-gi province, and Busan City; they are 100-300 m tall; and they are multi-use residential and commercialbuildings. The purpose of this study is to determine special features of super-tall buildings in Korea through the value of theirdisplacement contribution factor, calculated using the principle of virtual work. Ultimately, the most effective methods forcontrolling lateral drift are controlled analysis of real structural models using computer programs. Effects of lateral load-resisting systems are evaluated and compared in this study. Consequently, the most effective members for controlling lateraldrift are presented in this study through an analysis using computer programs on a real structural model.

Keywords: Super-tall building, lateral drift control, principle of virtual work, displacement contribution factor

1. Introduction

1.1. Social background

Six Korea high-rise buildings are ranked among the

world’s tallest buildings. In the last decade, Korean

construction companies have built high-rise buildings such

as the KLCC and Telecom builiding, overseas buildings,

and so many domestic high-rise buildings 100-300 m

high (Fig. 1).

As a result, Korea now has more than 70 over-100-m-

high buildings mostly in Seoul City and Busan City. In

addition, over-100-story building projects have been

announced one after another, and so many tall buildings

are still under construction (Fig. 2).

1.2. Research objective and background

A survey carried out during the 1st KSTBF International

Symposium (2002) showed that the necessity of super-tall

buildings is acknowledged by 70.6% of.experts and the

public in Korea.

Current circumstances such as demand for ESSD

(Environmentally Sound and Sustainable Development)

and the search for a solution to population explosion are

leading to expectations that tall buildings will be continually

constructed. Hence, technologies for constructing super-

tall buildings in Korea have shifted from those in the

initial phase to more advanced technologies.

Tall buildings are uniquely characterized by the prime

necessity for lateral loads to be considered in their design.

Two types of loads normally associated with lateral loads

are wind and earthquake loads.

This study first analyzes emerging issues with respect

to Korean super-tall buildings (STBs), then selects

existing or proposed structural systems of tall buildings,

analyzes these structural systems using a computer

program, calculates the displacement contribution factor

*Corresponding authorTel: +82-2-718-4688, Fax: +82-2-702-0959E-mail: [email protected]

Technical Article

Figure 1. Chart of height of buildings in Korea.

238 Young-Hak Kim and Sung-Woo Shin

of the structural components such as the beam, column,

shearwall, and outrigger using the principle of virtual

work, and evaluates the results.

Therefore, this study aims to present data for effective

structural control of lateral drift.

1.3. Research method

In this study, after analyzing a structural model similar

to a real structural model using a computer program

(MIDAS Genw. 5.8.1) and values calculated as one

member force of each structural component under the

ultimate loading condition and the member force of each

structural component under the unit load (P = 1), the

displacement of each structural component is calculated,

and then the value is divided by the volume of each

component. Finally, the impact on the relative size and

locations of various structural elements is evaluated.

2. Emerging Status of Structural Systems of STBs in Korea

Korean super-tall buildings are mainly located in Seoul

City, Kyung-gi province, Sung-nam City, and Busan City;

are 100-200 m tall; and are mostly multi-use residential

and commercial buildings.

In selecting the structural systems, economic considerations

demand that the economics of the structural system be

considered the most important factor in Korea. The

possible structural systems for the defined high-rise buildings

are: a reinforced concrete shearwall + a moment-resisting

frame (MRF), a reinforced concrete shearwall + an outrigger

system, a tubular system, a multi-tubular system, and a

mega-structure system. Among these, the structural system

composed of a shearwall with high-strength concrete in

its core, a moment-resisting system, and an outrigger is

the more popular structural system in Korea (Table 2).

The quest for more efficient structural systems has led

to a new generation of hybrid mixed steel and concrete

building structures.

The displacement contribution factor of each component

is calculated by applying it to the lateral resisting system

of Korean super-tall buildings that consist of a reinforced

concrete corewall, a moment resisting frame, and an

outrigger and beltwall system. The purpose of this study

is to find the most essential element in controlling lateral

drift and to suggest the most effective method of lateral

drift control.

3. Importance of the Core Position in the Building Plan

The higher the building is, the more important it is to

solve the vertical flow. For an effective structural system,

it is important to determine the shape of the building plan

and to determine the position of the core in the plan.

Lotte world II (555 m) Lotte world II (510 m)

Figure 2. Korea super-tall building projects being planned.

IBC130 Project (570 m) Songdo tower (510 m)

Figure 3. Super-tall buildings in Seoul.

A Study on the Effective Lateral Drift Control of Super-tall Buildings in Korea 239

3.1. Classification of STBs in Korea according to plan

type

Table 3 presents the types of plans of Korean super-tall

buildings, which are generally classified into 8 groups.

3.2. Study on the efficiency of building plans

according to the building’s core position

To design super-tall buildings effectively and economically,

the position of the core in the plan should be carefully

determined. This study demonstrates a simple example

using a 60-story building structural analysis model that

has the same size plan under the same loading condition.

The design variable is the position of the core in the plan;

the central reinforced concrete corewall, the eccentric

Table 1. List of Korea’s Super-tall Buildings

Rank NameNo. ofstories

Height(m)

Type of plan Structural system

1 Tower Place 69 261 YRC Core + RC Belt Wall (16, 55 F) +

SRC Column

2Hyperion (Mok dong)

A 동69 256 X RC Core + MRF + Outrigger Truss (9, 32, 50 F)

3 KLI 63 building 60 249 Rectangular MRF + Interior Brace

4 Tower Place I 66 234 BoxRC Core + Steel Outrigger with Belt Truss +

SRC Column

5 Trade Tower 54 228 Box RC Core + MRF

6 Star Tower 45 206 RectangularRC Core + MRF + Outrigger/Belt Truss/Cap

Truss

7 Tower Palace 55 195 Box+BoxRC Core + Steel Outrigger

With Belt Truss + SRC Column

8 Techno Mark (Kang Byun) 39 189 - -

8 ASEM Tower 41 170 - Tube + Brace + Moment Frame

10 Lotte World (Busan) 41 167 - -

Table 2. Lateral force resisting system in Korea

Table 3. Types of plans of Korean super-tall buildings

Rectangular Boxed Triangular Box + Box

Y T X Free

Figure 4. Analytical models.

Figure 5. Diagram of test results.


Table 4. Analytical model (Real structural model in Korea)

Group NameLateral force resisting system

Shearwall MRF Outrigger Belt Truss Number(s) Outrigger position

A

H-239-A O O O O 4 9, 30, 50, 69 F

C-175-A O O O O 1 19 F

S-145-AA O O O O 1 15 F

D-133-A O O O O 2 23, 43 F

H-106-A O O O O 1 10 F

B

H-156-C O O × × - -

D-129-AA O O × × - -

HW-109-Y O O × × - -

C

S-81-B O O × × - -

S-79-B O O × × - -

S-56-B O O × × - -

H - 239 - A

A: Type of plan

239: Overall height

H: Construction company

Table 5. Lateral force resisting system with outrigger

Lateral force resisting system with outrigger

H-239-A C-175-A S-145-AA

D-133-A H-106-A

Table 6. Lateral force resisting system without an outrigger

Lateral force resisting system without an outrigger

H-156-C D-129-AA HW-109-Y

Table 7. General structural buildings

Approximately 20-story structural buildings

S-81-B S-79-B S-56-B


reinforced concrete corewall, and the exterior reinforced

concrete corewall (Fig. 4).

The results show that the most effective case is the

application of the central core, the second eccentric core,

and the third exterior core. If the application of the

exterior corewall will be used, however, a reinforced

concrete brace should be used. This is very unreasonable,

though.

Figure 5 graphically shows the difference according to

the application of concrete compressive strength.

Table 8. H-239-A diagrams

Displacement contribution factor of H-239-A

Beam

Column

Outrigger

Truss

Wall

Table 9. C-175-A diagrams

Displacement contribution factor of C-175-A

Beam

Column

Outrigger&

Belt Truss

Wall


4. Analysis of the Displacement Contribution Factor

Once the structural layout of a tall building is defined,

the main effort is to size the structural elements to satisfy

the lateral serviceability performance criteria.

Generally, under wind or seismic loading conditions,

the lateral top deflection is limited to H/500 and the inter-

story drift is limited to 0.015 h, where H is the overall

height of the building above the pile cap level and h is the

story height in Korea.

Using the principle of virtual work, explicit serviceability

stiffness constraints can be expressed in terms of the

cross-sectional properties of the structural elements.

4.1. Analytical method of determining the

displacement contribution factor

4.1.1. Principle of virtual work

The exterior virtual work (∆ext) done by a unit load (P

= 1) in a linearly elastic structure is the verified work

done by a unit load while accruing virtual deformation, as

shown in Eq. (1).

Wext = 1 · ∆ (1)

Deformation occurs by unit load (P = 1). The interior

virtual work is shown in Eq. (2).

Wext = (2)

The deformation is presented in Eq. (3) based on the

virtual work.

∆ = (3)

Using the unit loading method, the maximum lateral

drift of the building is calculated. Adding this to the unit

load (P = 1) at the top position of the building in the same

NN

EA-------- xd

0

l

∫MM

EI---------- xd

0

l

∫feVV

GA----------- xd

0

l

∫TT

GI------ xd

0

l

∫+ + +

NN

EA-------- xd

0

l

∫MM

EI---------- xd

0

l

∫feVV

GA----------- xd

0

l

∫TT

GI------ xd

0

l

∫+ + +

Table 10. S-145-AA diagrams

Displacement contribution factor of S-145-AA

Beam&

Outrigger

Column

Wall

Table 11. D-133-A diagrams

Displacement Contribution Factor of D-133-A

Beam&

Outrigger

Column

Wall


direction, the sum of the values of the components is the

lateral drift of the building.

4.2. Analysis of the displacement contribution factor

in a real structural model

4.2.1. Analytical structural model

Table 4 presents 11 analytical models. The structural

systems are classified into three groups. One group

consists of five models with outrigger systems, another

group consists of three models without outrigger systems,

and the third group consists of three 20-story or so

models. The variables are the structural height and the

outrigger system.

4.3. Analysis of the displacement contribution factor

of structural components

4.3.1. Displacement contribution factor of H-239-A

The outriggers are located at the 9th, 30th, 50th and

69th floors. Thus, stiffness is more significant on these

floors than on other floors.

The displacement contribution factor of the truss and

the beam is distributed uniformly. In the upper floors, the

outrigger affects the column more than the wall, so that

the what? of the column is larger than that of the upper

floors.

The outrigger on the upper floors contributes more than

the outrigger on the lower floors.

4.3.2. Displacement contribution factor of C-175-A

The rigidity of the upper and lower floors and the

outrigger is larger than that of the other floors.

The displacement contribution factors reach their

maximum value on the 19th floor.

4.3.3. Displacement contribution factor of S-145-AA

The residential and commercial building, S-145-AA,

has a marked stiffness at its podium.

The displacement contribution factor of the beams is

influenced by the outrigger on the middle floor. That of

the columns and walls on the lower floors is relatively

large.

The outrigger on the 15th floor has maximum value.

4.3.4. Displacement Contribution Factor of D-133-A

The stiffness of the lower floors is large. The rigidity of

the wall on the 41st floor is larger than of the beam on the

23rd floor.

Table 12. H-106-A diagrams

Displacement contribution factor of H-106-A

Column

Wall

Table 13. H-156-C diagrams

Displacement contribution factor of H-156-C

Beam

Column

Wall


4.3.5. Displacement contribution factor of H-106-A

The stiffness of the lower and upper floors is large. The

rigidity of the beam on the 10th floor is larger than on the

other floors.

4.3.6. Displacement contribution factor of H-156-C

The structural system consists of a flat slab and a

reinforced concrete shearwall that affect the displacement

contribution factor of the beams.

The value is especially large at the beams on the middle

floor.

4.3.7. Displacement contribution factor of D-129-AA

The structural system is similar to that of H-156-C.

Also, the results were similar to those shown in Table

13.

The value is especially large at the beams on the middle

floor.

4.3.8. Displacement contribution factor of HW-109-Y

This structural model has a transfer layer on the 2nd

floor.

Table 14. D-129-AA diagrams

Displacement contribution factor of D-129-AA

Beam

Column

Wall

Table 15. HW-109-Y diagrams

Displacement contribution factor of HW-109-Y

Beam

Column

TransferGirder

Wall


The displacement contribution factor of the beam is

distributed equally on all floors.

4.3.9. Displacement contribution factor of S-81/79/

56-B

These buildings were selected to evaluate the behavior

of super-tall buildings in Korea.

The displacement contribution factor of the beams is

distributed equally on all the floors.

5. Conclusions

In this paper, the lateral resisting system was analyzed

and the most effective method of lateral drift control was

suggested.

The results of the study are as follows.

a. To control the lateral drift effectively, the structural

system consisting of a reinforced concrete corewall,

a moment-resisting system, outriggers, and a belt

wall is popular in Korea.

b. In the case of the usage of an exterior corewall in the

plan, a concrete brace should be used in the

reinforced concrete building.

c. The structural system consisting of a reinforced

concrete corewall, a moment-resisting frame, and an

oOutrigger is common in Korea.

d. To determine the structural system of a super-tall

building, a Korean construction company reviewed

the structural system at the point of economic

efficiency.

e. It is important to determine the position of the core

in the plan close to the center to promote the

efficiency of the structural system.

f. The value of the displacement contribution factor is

as follows:

- In the structural system with an outrigger:

Wall > Beam > Column

- In the structural system without an outrigger:

Wall > Column > Beam

g. The curve of the displacement contribution factor is

similar to the curve of the stiffness ratio of the

building.

h. In using a structural member such as an outrigger,

the stiffness of which is higher than of others, the

displacement contribution factor also has a higher

factor. Moreover, in using an outrigger system, the

position of the outrigger must be considered carefully.

i. The stiffness curve of the structural models, the

lateral drift curve, and the displacement contribution

factor curve have a similar behavior.

j. Generally, stiffness is inversely proportional to stiffness;

but the concentration of the stress makes the drift is

larger.

Acknowledgments

The authors would like to thank MIDAS IT and

STRESS (advanced STructure RESearch Station) at

Hanyang University for their technical support.

References

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A. Jaafari (1998), Cost and Performance Analysis of Tall

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Alex Coull and W. H. Otto Lau (1989), Analysis of Multi-

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Displacement contribution factor of S-81-B

Beam

Column

Wall


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A Study on the Effective Lateral Drift Control of Super-tall Buildings …C).pdf · 2018-01-08 · A Study on the Effective Lateral Drift Control of Super-tall Buildings in Korea