space shear wall as an innovative seismic resistant … shear wall as an innovative seismic...

INTERNATIONAL JOURNAL OF CIVIL AND STRUCTURAL ENGINEERING

Volume 3, No 2, 2013

© Copyright by the authors - Licensee IPA- Under Creative Commons license 3.0

Research article ISSN 0976 – 4399

Received on September, 2013 Published on November 2014 203

Space shear wall as an innovative seismic resistant system for structures Behzad Bayat, Mohd. Zulkifli M. Ghazali, Mahmood Tahir

Faculty of Civil Engineering, Universiti Teknologi Malaysia (UTM)

[email protected]

doi: 10.6088/ijcser.201304010021

ABSTRACT

Optimisation of stiffness, ductility and construction cost is the main challenge for structural

engineers in attempting to create an excellent lateral system. Conventional seismic systems

like braced frames and shear walls could not completely satisfy engineers due to excess

rigidity, and low ductility. Then innovators developed advanced ductile structural systems

like viscous elastic dampers to dissipate earthquake forces and insulate important structural

elements in safe zone; however these systems have not been pervasive in construction

industry due to high production cost. This paper introduces an innovative application of space

frame system as Space Shear Wall (SpaSW) to overview its feasibility and advantages for

seismic performance enhancement. This concept has initially been formed based on the

double-layer diagonal spatial structures with Mero connections. In conclusion high stiffness,

ductility and energy dissipation, lightness, industrialization, maintainability and reparability,

compatibility with architectural considerations, low cost, simple and fast fabrication are the

main expected advantages of this system. Developing this concept would be considered in the

future studies through optimization of material, grid patterns, connection, and additional

dampers.

Keyword: Space Shear Wall, SpaSW, Innovation, Seismic System, Spatial Structure, Space

Frame, Earthquake.

1. Introduction

Over the past decades, earthquake and wind hazards have seriously influenced structural

engineering principals. In this respect, major advances have occurred in both understanding

and practice of seismic force-resisting systems. Therefore, various kinds of seismic systems

were created to protect buildings from natural disasters but most of these systems could not

completely satisfy engineers. Critics believe that common rigid systems can absorb the

earthquake energy and transfer it to the structural elements. Hence engineers introduced

ductile seismic systems to dissipate dynamic forces and insulate important structural elements

in safe zone. A ductile seismic system under earthquake loading performs like a fuse box in

an electrical board, which is an essential safety device that cut off the flow of electricity if a

fault occurs and protect individual circuits that carry electricity to the various applications.

However, the use of ductile systems has resulted in invention of many advanced systems like

base isolators and viscous elastic dampers, but these high-tech systems have not commonly

been used due to their high costs and complicated fabrication. Concisely, optimisation of

stiffness, ductility, and construction cost are the major challenges facing the engineering

profession in designing a perfect lateral system. Space structure is a three dimensional truss

with high stiffness and ductility due to its numerous members and flexible joints. Many high

rise and long span structures have been constructed based on this sophisticated system as

well.

Space shear wall as an innovative seismic resistant system for structures

Behzad Bayat et al

International Journal of Civil and Structural Engineering

Volume 3 Issue 2 2013

204

This paper introduces an innovative application for space grid system as Space Shear Wall.

Behzad Bayat (2010) presented a research proposal to Universiti Teknologi Malaysia to study

on suitability of space shear wall to perform as ductile, stiff and low cost seismic system.

This concept has initially been formed based on two-way diagonal spatial structures with

Mero joints; however, developing this system would be considered in future studies through

optimization of materials, grid patterns, connections, and additional dampers. Initial literature

research proves that this concept has not been proposed as yet. The main challenges of

common lateral systems are found to be as follows: a) High rigidity and low ductility (e.g.

cross bracing), b) High cost like (e.g. viscous elastic dampers), c) Inability for

industrialization (e.g. concrete shear wall). This paper presents the space shear wall to cover

the weakness points of common lateral systems as mentioned above. Based on this paper,

further study would be undertaken to turn the concept of using Space frame system to an

innovation of a new seismic system to improve the ductility and energy dissipation of

structures.

2. Literature Review

Space structure is a three-dimensional structural system assembled in single, double or

multiple layers with interlocked strut elements and joint-connections (Nooshin, 2013). Space

frame connection is the most determinant component in order to connecting linear members

and distributing the imposed loads in three-dimensional manner (Lan, 2012). In 1880 August

Foppl introduced space structures through his treatise. This invention aided Gustave Eiffle for

his tower analysis and later was developed by Graham Bell to provide the rigid space frames

for nautical and aeronautical engineering (Russell, 2003). Bell constructed the first space grid

structure for observation tower at Beinn Bhreagh, USA, in 1907. In 1928 Max

Mengeringhausen innovatively introduced Mero system consist of steel tubes interconnected

into steel nodes on geometric pattern which is still is the most common method of space

frame construction. Through 1950s, Denings of Chard created space deck system using

prefabricated steel pyramidal modules and developed this system in the construction of army

barrack blocks. Engineers’ intention to accommodate the large unobstructed span developed

the applications of space structures. In the USA, Richard Buckminster Fuller (1895–1981)

continued his investigation on closest packing of spheres and developed the Octet Truss

system. Recognition of the innovative work of Richard Buckminster Fuller could recognize

and speed up the acceptance of space grid structures through adoption of a 76 m diameter,

three-quarter sphere, and geodesic dome for the US pavilion in Montreal, Canada (Chilton).

The use of continuous cold-formed steel sections for the top and bottom chord members of

node-less space trusses resulted in development of cheaper and lightweight systems in 1980s.

Simultaneously, the advancement of computer programs rendered the tedious manual

calculation obsolete. These programs are capable to analyze the large space structures

accurately in less time involved. This system is extremely being used in the total range of

construction types, like sport stadiums, transportation terminals, industrial factories, airplane

hangars, domes, hyperbolic roofs, and exhibition pavilions. In 2004, Robert A. Halvorson

and Partners provided the structural solution for a competition on high rise buildings in Milan.

This proposal consists of diagonal steel bracing with rigid connection linked to the concrete

wall elements. This solution provided a proper lateral stiffness and also great transparency in

both the units and the central spaces. In addition, Halvorson designed an innovative braced

spine structural system for the Russia tower that is the Europe’s tallest building with a total

height of 612 meters (Halvorson, 2008).


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3. How the Idea of Space Shear Wall Has Been Formed

The idea of SpaSW is based on the capability of space trusses to resist the lateral forces

generated by the seismic activities. Such lateral forces may be resisted quite effectively by

integration of three-dimensional structures with two dimensional lateral systems like cross

bracing as illustrated in Figure 1, where the building frame is designed to carry the vertical

loads, and the bracing the lateral force. Whereas most of the seismic systems only perform

under the in-plane loads, a new concept can be discovered through integration of three-

dimensional seismic systems with structural frames as shown in Figure 2 Originally this

concept has been inspired from a special tree that situates its upper ground roots into three

directions to resist the wind load as per Figure 3 Therefore, the evidences show that a three

dimensional system like spatial truss can be introduced as an individual seismic system in

concrete and steel frames. Figure 4 shows the perspective of SpaSW in R.C frame.

Figure 1: Forming a Common Seismic Systems i.e. Cross Bracing

Figure 2: Early Concepts for Space Shear Wall based on adding a three dimension system to

building frame

Figure 3: Natural inspired model of space shear wall


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Figure 4: Initial Concept of Space Shear Wall

4. Expected Advantages of Space Shear Wall

According to appropriate structural performance of space truss under past earthquakes and its

unique characteristics, high stiffness, ductility and energy dissipation, lightness,

industrialization, maintainability and reparability, compatibility with architectural

considerations, low cost, simple and fast fabrication are the major advantages of SpaSW.

4.1 High Stiffness

Space structure is adequately stiff due to its three-dimensional geometric and proper

contribution of its interconnected elements for load taking (Ramaswamy, et al., 2002). Table

1 shows a list of famous space structures with their free span length and carried dead load.

The large free span and imposed heavy load in existing space structures demonstrate the high

stiffness of space structures.

Table 1: Examples of Famous Buildings Using Space Frame Structures (Karni, 1996)

4.2 High Ductility

Ductility is the ability of nonlinear structural systems, to be stressed beyond its yield strength

and into its plastic range with large elongation before rupturing in a ductile mode (SEAOC,

1995). The ratio of ultimate deformation to the yield deformation drives the ductility factor

for Single Degree of Freedom systems. Basically, the sources of ductility and nonlinearities

Project Free Span (m) Dead Load(kPa)

Currigan Hall 55 -

Sao Paulo Exhibition Center 60 -

Boeing 747 Hanger, London Airport, 1970 84 11.1

Omni Coliseum 107 7.3

Expo 68, Osaka 108 15.2

Pauly Pavilion 122 7.8

Kloten Airport, Zurich, 1975 128 18.8

Nartia Airport, Tokyo, 1972 190 25.6


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are material, plastic deformation, cross-section deformation, geometric system, friction, and

connections (Gioncu and Mazzolani, 2002), (Fadaee and Bayat, 2007). Therefore SpaSW

would perform as nonlinear ductile system due to its potentials for deformation without

significant failure, geometric pattern, and out-coming friction on connections.

4.3 High Damping

Damping is the energy dissipation mechanism of free vibrant system. In actual structures,

many mechanisms like exothermal impact of cyclic straining on material, friction at nodal

joints, creation micro cracks, rotation and deflection of linear members and connections, and

interaction between the structural and nun-structural elements lead to energy dissipation

(Chopra, 2012). SpaSW ball joints allow structure to displace and rotate members and this

process makes space structure to undergo deformations after its yield stress and dissipate the

seismic energy. In addition, rupture of several members and connections of space frame may

not result to whole the system failure.

4.4 Lightness

Lightness is the most significant advantage of space structures due to its spatial distribution

of light hollow section members. Simply support ball joints let isolate members from moment

and convert the imposed load into tension and compression can be withstands by nominal

hollow sections. In addition, space frames are mainly cast by steel or aluminum, which

considerably reduces structure self-weight compared to concrete structures. The self-weight

of SpaSW is approximately around 30 kilogram per square meter; however, this quantity for

steel bracing is 40 and for concrete shear wall is 480 kilogram per square meter.

4.5 Ability to be Industrialized

The space frame units are widely fabricated in the factory to use the industrialization

advantages. This structural system can be made from simple manufactured typical modules.

These units would be simply transferred and rapidly assembled on construction site by semi-

professional workers which all minimize the construction expenses (Lan, 2012). Since the

initial concept of SpaSW is based on common type of space systems, they can be produced

by existing manufacturers without requiring advanced and complex technologies. This kind

of industrialization distinguishes the SpaSW compared to the other seismic system such as

steel bracing, concrete shear wall, and viscous elastic dampers.

4.6 Compatibility with Architectural Consideration

Architects intention to create long spans and minimize the vertical structural elements

resulted in development of space structures in past decades. Space frame structure is a

valuable system for the architect and engineer in the search for new forms, owing to their

wide diversity, application, and flexibility. Using this system brings opportunities to integrate

structural and architectural elements, together. Lord Norman Foster is one of the most famous

architects that have high intention to utilize the exposed spatial structural elements in his

architectural design, as shown in Figure 5. Perimeter space frames are structurally very

efficient in high-rise buildings; however their perimeter structural members may interference

the openings at facades. The main challenges of structural-architectural integration of space


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frames refers to the interior view; however architects practically utilize the space members as

exposed architectural elements. Sutjiadi and Charleson (2012) investigated on challenges of

structural-architectural integration of various types of space grid in high-rise buildings as

demonstrated in Figure 6 (Sutjiadi and Charleson, 2012). According to stated evidences, it

can be concluded not only utilizing space frame structure as shear wall is compatible with

architectural design, but also many architects have shown high intention to consider the

exposed space frame as part of their design. Therefore, SpaSW would be introduced as a

compatible seismic system for architectural considerations.

Figure 5: Architectural-Structural Integration of Space Grid Structures a) 30 St Mary Axe,

London b) Hearst Tower, New York c) Almaty Twin Tower, Almaty d) Double-Layer Space

Structure of an un-built 150 storey Project, Chicago e) Gakuen Spiral Tower, Nogoya f)

Skytree Tower, Tokyo


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Figure 6: a) A Section of Three-Storey Building Using Boundary Double-layer Space

Structure b) Exposed Structure Using Exterior Space Frame c) Typical Interior Area Affected

by Perimeter Space frame d) Typical Balconies Surrounded by Space Structure e) Using

space Frame Structural Elements in Façade Design f) Curved external glazing (Sutjiadi and

Charleson, 2012)


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4.7 Maintainability and Reparability

The large majority of space frames includes steel members with a yield strength ranging from

210 to 450 MPa and welded or bolted connections. Using space frame as exposed system

brings a unique opportunity to be maintained by re-coating against corrosion during the

service period. Moreover the failed members might be replaced by new members and

connection, if they fail under natural disasters like fire, earthquake, etc. Buck minister

Fuller’s dome is a good example for reparability of space structure. In 1967 a distinctive

Buckminister Fuller’s geodesic dome was constructed in Montreal, Canada. After 9 years,

spectacular fire caused by welding works during maintenance operation destroyed the entire

outer acrylic cover. In 1992, Canadian government appointed professional architects to

redesign the layout to comply the new application, and engineers to treat the steel members

with anti-corrosive paint. Finally a new building was opened on 1995, as Canada’s first

Ecowatch Centre (EC, 2009).

4.8 Ability for Retrofitting of Structures

Recent earthquakes like Kobe and Northridge have shown the vulnerability of huge numbers

of existing buildings. Generally, retrofitting techniques include treating material, and

enhancing the lateral stiffness by adding a new seismic system to the building. Space frame is

a suitable option for retrofitting the existing structures in terms of high stiffness and ductility

and its lightness. Sumikei-Nikkei Engineering Company invented the SNE-Truss as a seismic

retrofit technology, to reinforce existing concrete buildings. SNE-Truss reinforces existing

concrete buildings from the outside of the structure using aluminum alloy space grids latticed

wall. The purpose of reinforcing the existing structure is improvement of the seismic capacity

of existing RC buildings by the in-plane strength and stiffness of this aluminum-latticed wall.

Figure 7 illustrates a computer graphic drawing of existing RC buildings reinforced by SNE-

Truss. The main characteristics of SNE-Truss include: 1) The adaptability with existing RC

buildings for retrofitting works; 2) The minimal self-weight and a high strength of aluminum

used in SNE-Truss, and 3) The high performance of corrosion resistance of aluminum

(Kabeyasawa, 2005).

Figure 7: Computer graphic drawing of existing R/C buildings reinforced by SNE-

Truss (Kabeyasawa, 2005)


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Figure 8: Retrofitted Building of Shiraz University of Medical Science, Iran

Figure 8 shows Shiraz University of Medical Science, Iran, retrofitted by space frame

structures. This three dimensional exposed frame is significantly efficient in controlling the

settlement of building and enhancement of lateral stiffness.

4.9 Low Cost

Space frame systems are produced by normal material like mild steel or aluminium.

Therefore this system is considered as a low cost system due to its lightness, constitute

material, industrial prefabrication and reducing construction duration. Moreover, the cost of

this industrial system can be competitively minimized by suppliers in market compared to the

other seismic system that should be executed in construction site by contractors.

4.10 Simple and Fast Construction

There are 250 different types of jointing system in the world fabricated through many space

frame manufacturers. Although every type is designed for a special application but most of

them are in common in simplicity. This simplicity beside the industrialization of space frame

system leads to significant reduction of construction period compared to the in-situ systems

like concrete shear wall.

4. The Conceptual Detail of Space Shear Wall (SpaSW)

The success of space structures under earthquake and wind loads proves that even this

system can be proposed as an individual seismic system especially in high-rise buildings.

This article elaborates the innovative implementation of space system as Space Shear Wall

(SpaSW) to create high ductile, stiff and economic seismic system. Although this study start

with SpaSW using double layer diagonal system with Mero joints but authors plan to

develop this system via optimization of material, grid patterns, connection, and adding

dampers in the future plans. Figure 8a to 8d show the three-dimensional view of SpaSW

surrounded by beam and columns.

As it can be seen from Figure 8, the SpaSW included internal and external layer that are

linked together through inner members. The diagonal members take the lateral load as an

axial force from column and beam and distribute to other members. Figure 9 shows the

distribution of lateral load into the space frame members. The inner members reduce the

effect of out of plane buckling and also they perform as compressive members under out of


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plane earthquake load. Moreover, Table 2 evaluates the capabilities of SpaSW compared to

common lateral systems.

Figure 8: Three Dimensional Model of Diagonal and Two-Way SpaSW

Figure 9: Distribution of Lateral Loads into the SpaSW Members

Table 2: Comparison of SpaSW Features with Common Lateral Systems

No. Feature SpaSW CB* CSW*

* 1 High stiffness √ √ √

2 High ductility √ × ×

3 Lightness √ √ ×

4 Ability to be industrialized √ × ×

5 Compatibility with architectural

considerations

√ √ √

6 Maintainability √ × ×

7 Reparability √ √ ×

8 Ability for retrofitting structures √ √ ×

9 Low cost √ √ ×

10 Simple and fast fabrication and

installation

√ √ ×

*CB: Cross Bracing; **CSW: Concrete Shear Wall

C

C

C T

T

Earthquake Load


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5. Conclusion

This paper introduces an alternative application of the space frame system as Space Shear

Wall (SpaSW). The successful performance of the space structure would prove that this

system even can be utilized as an individual shear wall in structures. High stiffness, ductility

and energy dissipation, lightness, ability to be industrialized, maintainability, compatibility

with architectural considerations, reparability, having low cost, simple and fast fabrication

would be anticipated as the main advantages of this system. This system due to having

numerous members and bolted joints would be able to absorb the harmful energy of

earthquake and keep the surrounded frame in elastic zone. This study is currently going on

early work that SpaSW can be fabricated in factory and installed in construction site to create

a high stiff-ductile system especially for high rise buildings. Moreover this system is able to

carry part of vertical load as well as out of plane lateral load.

6. References

Chilton, J., (2012), Space Grid Structures. Architectural Press, ISBN 0750632755, 1-

11.

Chopra, A. K., (2012), Dynamic of Structures; Theory and Application to Earthquake

Engineering. 3rd Edition. ISBN 0-13-156174-X.

Environment Canada (EC), (2009), Richard Buckminster Fuller, Retrieved June 3,

2013 from http://www.ec.gc.ca/biosphere/default.asp?lang=En&n=30956246-1.

Fadaee, M. J., and Bayat, B., (2007), Effects of Using Low Yield Point Steel instead

of Normal Steel in Steel Shear Walls. 11th International Conference on Civil,

Structural and Environmental Engineering Computing, Civil-Comp Press,

Stirlingshire, UK, Paper 209, 2007. doi:10.4203/ccp.86.209.

Gioncu, V., and Mazzolani. F., (2002), Ductility of Seismic-Resistant Steel Structures,

Spon Press. ISBN-10: 0419225501.

Halvorson, R. A. (2008), Structural Design Innovation: Russia Tower and Other Tall

Collaborations. CTBUH 8th World Congress, Dubai, EU, March, 2008.

Kabeyasawa, T., (2005), Recent Development of Seismic Retrofit Methods in Japan.

Japan Building Disaster Prevention Association.

Karni, E., (1996). Plastic cladding for bar, joint and cladding structures physical

properties and performance. Materials and Structures, Vol. 29, May 1996, pp 241-249.

Lan, T. T., (2012), Space Frame Structure. In: Chen, W. F. & Lui, E. M. ed.,

Handbook of Structural Engineering, Second Edition, Taylor & Francis. ISBN 0-

8493-1569-7 CRC Press, 24.1-50.

Nooshin, H., (2013), What is a Space Structure? Official Website of Surrey

University, Space Structures Research Centre. Retrieved August 4, 2013, from

http://portal.surrey.ac.uk/portal/page?_pageid=822,568927&_dad=portal&_schema=P

ORTAL

http://www.ec.gc.ca/biosphere/default.asp?lang=En&n=30956246-1


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Russell, J. S., (2003), Perspectives in Civil Engineering: Commemorating the 150th

Anniversary of the American Society of Civil Engineers, American Society of Civil

Engineers (ASCE) Publications, ISBN 0784475385, 157.

Structural Engineers Association of California (SEAOC), (1995), Applied

Technology Council (ATC) & Caifornia Iniversities for Research in Earthquake

Engineering. Steel Moment Frame Connections. Advisory No. 3, SAC-95.01, D-146.

Sutjiadi, H. Y., and Charleson, A. W. (2012), Structural‐Architectural Integration of

Double‐Layer Space Structures in Tall Buildings, Journal of Architectural

Engineering. doi: 10.1061/(ASCE)AE.1943-5568.0000096.

Ramaswamy, G. S., Eekhout, M., & Suresh, G. R., (2002), Analysis, Design and

Construction of Steel Space Frames, Thomas Telford.

space shear wall as an innovative seismic resistant … shear wall as an innovative seismic...

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