2.1 Introduction

This chapter is discussing on the previous of related studied done by other researcher. In this chapter, an overview of demand of high rise building and wind behavior in Malaysia are discussed. The existing lateral system such as shear wall and proposed new system, space shear wall are also discussed. The lateral performance of high rise building is also presented when exerting lateral loading.

2.2 High Rise Building

A ‘tall building’ is defined as a multi-story structure in which most occupants reach their destinations on higher floor depend on elevators (lifts) (Craighead, 2009). This tall building can be categorized as low, mid, high and super high rise (skyscraper). The low rise building is defined as less than four stories, mid rise is considering from five up to fifteen stories, while high rise is ranging from sixteen to fifty and more than fifty stories is the skyscraper (Fadzil, 2016).

Besides, The National Fire Protection Association (NFPA) defined a high-rise building as a building taller than 75 ft (23 meters) in height measured from the lowest level of fire department vehicle access to the floor of the highest occupiable storey (Mohamad Yatim, 2009). Another opinion says a high-rise structure is one that extends higher than the maximum reach of available fire-fighting equipment and it is between 75 ft and 100 ft (23 meters to 31 meters) (Craighead, 2009).

The overall slenderness of a high rise building is defined by its “height-to-base ratio”, being the height of the building divided by its narrowest plan dimension. Basically, higher height-to-base ratios and lower natural frequencies increase the dynamic component of the response to wind. A building with a height-to-base ratio of more than around 5 is expected to respond to wind loads in a significantly dynamic way (where building inertial effects are significant) (Kayvani, 2014).

In fact, New York’s most advanced towers are defined not by their height but by their width or rather, their slenderness. The slenderness ratio is defined as the ratio between a building’s height and its smallest width. For example, a 1,000ft (310m) height of tower that has 100ft (31m) at its narrowest width would have a slenderness ratio of 10:1. “The slenderness of a building is maybe more important than anything else,” said by Silvian Marcus, director of building structures at WSP USA (Runaghan, 2014). In New York’s building code, designs for buildings over 600ft (183m) and any building with a slenderness ratio above 7:1 must be peer reviewed by another engineering practice (Runaghan, 2014).

Therefore, the issue of slenderness must also be considered. A measure of a building’s slenderness is the aspect ratio. For core wall only lateral systems, ratios typically range from 10:1 to 13:1. For lateral systems that engage exterior elements, an aspect ratio up to 8:1 is feasible. Pushing this ratio up to 10:1 can result in the need for special damping devices to mitigate excessive motion perception (Zils & Viise, 2013). The space shear wall system is considered as exterior lateral element, due to the consideration of authenticity in real construction, the ratio used in this research is 4:1.

2.2.1 Demand of High Rise Building

Nowadays, due to the increasing of population in urban areas in Malaysia such as Penang, Kuala Lumpur, Selangor and Johor Bahru, demand for housing is increasing and development of high-rise residential schemes is accelerated in these high-density areas due to scarcity of land for development of landed residential properties (Tiun, 2009). These high rise properties are being promoted because high rise living became a logical response to soaring of land prices. There are successful example countries that implement high rise such as Singapore and Hong Kong where the traditional lifestyle is high-density, high-rise living (Tiun, 2009).

In Penang, there is a trend of developers preferring to build tall building such as condominiums. In coming years, especially on Penang Island, there is a higher proportion of new high-rise units (Lim, 2015). According to Table 2.1, on the statistics obtained from the National Property Information Centre (NAPIC), it is estimated that there were at least 203,618 units of high rise properties inclusive of flats, condominiums and apartments are under constructing for incoming supply in Malaysia by the end of 2017 and the number is growing yearly. From the data, Penang is the third highest state in constructing more high rise building which is about 35,793 units. This is due to the high demand of housing in this developing area.

Table 2.1: Incoming Supply of High Rise Building in Malaysia as of Q3 2017

State Low Cost Flat Flat Condominium/ Apartment Total
Selangor 2887 6255 43859 53001
W.P. Kuala Lumpur 0 0 40460 40460
Pulau Pinang 7280 8256 20257 35793
Johor 2451 4451 13011 19913
Sabah 3562 418 12426 16406
Sarawak 0 0 8801 8801
Table 2.1 – continued

Perak 0 724 6264 6988
W.P. Putrajaya 0 0 6944 6944
Pahang 0 840 3488 4328
Negeri Sembilan 0 1684 1588 3272
Kelantan 218 1001 1451 2670
Melaka 250 324 1392 1966
Terengganu 640 35 612 1287
W.P. Labuan 0 0 1143 1143
Kedah 416 0 196 612
Perlis 0 0 34 34
Malaysia 17704 23988 161926 203618

Source: Residential Property Stock Table Q3 2017, NAPIC.

2.3 Size of Column and Beam

Based on a study on wind behavior of buildings with and without shear wall (in different location) for structural stability and economy (Gourav P. Bajaj, 2016), the column size is 600 mm x 600 mm and beam size is 500 mm x 300 mm. The building dimension is 20 m in length and 15 m in width with a height of 47.6 m. The research is about determination of shear wall application toward wind load which is similar to this study, the dimension of building is also almost similar in this study. Therefore, the size of column and beam is determined as 600 mm x 600 mm and 500 mm x 300 mm respectively.

2.4 Shear Wall

Shear wall is a structural element installed in a building to resist horizontal forces parallel to the plane of the wall. Due to its highly in plane stiffness and strength, it can resist large both horizontal loads and support gravity loads simultaneously (Sardar & Karadi, 2013). The main horizontal forces that are induces by the shear wall are wind, earthquake and other lateral forces. They are mainly flexural members and mostly provided in high rise buildings to avoid the total collapse of the high rise buildings under seismic forces, wind forces or other lateral forces (Gourav P. Bajaj, 2016). Figure 2.1 and Figure 2.2 show the construction of shear wall in high rise building.

Sources: Kopczynski, 2011

Figure 2.1: Construction of shear wall of 40-storeys residential tower at Eighth and Pine.

Sources: PERI Group, 2017

Figure 2.2: Construction of shear wall of 26-storeys Aspen Residence in George Town, Malaysia
When the buildings are tall, which are more than twelve storeys or so, the sizes of beam and column need to be constructed larger and reinforcement at the beam and column junction works become heavier, therefore, there is a lot of obstruction at to place and vibrate concrete at these joints, which generally will affect the safety of buildings (Gourav P. Bajaj, 2016). So, the present of shear walls in high rise buildings solves these practical difficulties. However, recent RC tall buildings would have more complicated structural behavior than before. Shear wall system with irregular openings are that undergoes both lateral and gravity loads, and may result some especial issues in the behavior of structural elements and stability of structure (Abd-El-Rahim & Farghaly, 2010). Besides, installation of openings in the shear walls can affect on the top displacements of the buildings and it is related with openings arrangement system of openings. The top displacement is agreed quit well with that induced in shear walls without openings but this obstructs the transmission natural lighting into the building (Abd-El-Rahim & Farghaly, 2010). Therefore, new system called space shear wall which is a combination of shear wall and space frame structure is introduced to modified traditional shear wall.

2.5 Space Frame Structure

Space structure is defined as a three-dimensional structural system assemble in single, double or multiple layer with interlocked strut elements & joint-connections (Bayat et al., 2014). Besides, innovation of space structures provided the domineering features emphasizing the giant impact exerted by three-dimensional structures upon modern architecture and structural engineering (Makowski, 2018). Space frame connection is the most determinant component in order to connecting linear members and distributing the imposed loads in three-dimensional manner (Bayat et al., 2014).

The space frame can be formed either in a flat or a curved surface. The earliest form of space frame structures is a single layer grid. By adding intermediate grids and including rigid connecting to the joist and girder framing system, the single layer grid is formed. The major characteristic of grid construction is the omni-directional spreading of the load as opposed to the linear transfer of the load in an ordinary framing system. Since such load transfer is mainly by bending, for larger spans, the bending stiffness is increased most efficiently by going to a double layer system. The load transfer mechanism of curved surface space frames essentially different from the grid system that is primarily membrane-like action (Wai-fah, 1999).

A good example of space structure is Baltimore-Washington International Thurgood Marshall Airport (BWI Airport) shown in Figure 2.1. Baltimore-Washington International Airport is an international airport located in Linthicum, an unincorporated community in northern Anne Arundel County, Maryland, United States. The airport has the signature space frame design while increasing passenger capacity and improving the traveler’s experience. The design is a 90-foot atrium, topped by a large skylight, floods the upper and lower levels, including waiting and shopping areas, with natural light, while supported by the steel space frame elements. This project even won the WBC (Washington Building Congress) Craftsmanship Award for the Metals/Structural Steel Categories (Airport Technology, 2018).

Sources: Airport Technology, 2018

Figure 2.3: Space frame structure of Baltimore-Washington International Thurgood Marshall Airport

The advantage of a space frame structure is lightweight properties. The material is distributed spatially in such away that the loads transfer mechanism are primarily axial loads which are in tension or compression (Makowski, 2018). Furthermore, space frames can be built from simple prefabricated units, which are often of standard size and shape. Such units can be easily transported and rapidly assembled on site by semi-skilled labor. Besides, space structure compatible with architecture aspect. Architects appreciate the visual beauty and the impressive simplicity of lines in space frames. A trend is very noticeable in which the structural members are left exposed as a part of the architectural expression. Desire for openness for both visual impact as well as the ability to accommodate variable space requirements always calls for space frames as the most favorable solution (Wai-fah, 1999).

2.6 Space Shear Wall

Space Shear Wall is space trusses to resist the lateral forces generated by the wind activities. Such lateral forces may be resisted quite effectively by integration of three-dimensional structures with two dimensional lateral systems like cross bracing, where the building frame is designed to carry the vertical loads, and the bracing the lateral force (Bayat et al., 2014). The concept of space shear wall can be simplified as the combination of shear wall and space structure. Figure 2.2 shows the initial concept of space shear wall.

Sources: Bayat et al., 2014

Figure 2.4: Initial Concept of Space Shear wall

The idea of Space shear wall is based on the capability of space trusses to resist the lateral forces generated by the seismic activities or wind activities. These lateral forces may be resisted by integration of three-dimensional structures with two dimensional lateral systems quite effectively where the building frame is designed to carry the vertical loads, and the space truss resists the lateral force (Sutjiadi ; Charleson, 2014).

The expected advantages of space shear wall are high stiffness, ductility and energy dissipation, lightness, industrialization, maintainability and reparability, compatibility with architectural considerations, low cost, simple and fast fabrication. These advantages are expected based on the structural performance of space truss under past earthquakes and its unique characteristics (Bayat et al., 2014).

Space structure is high stiffness due to its three-dimensional geometric and proper contribution of loading by its interconnected elements (G.S. Ramaswamy, M. Eekhout, G.R. Suresh, 2002). Table 2.2 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 2.2: Examples of Famous Buildings Using Space Frame Structures

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

Source: Bayat et al., 2014
Besides that, space shear wall is compatible with architectural consideration. Architects always wish to design long vertical structure with fewer structural components (Sutjiadi ; Charleson, 2014). Therefore, there is development of space structures in previous years. Space frame structure is a precious system that can optimise between engineer and architect to create a new forms, that provide wider application, flexibility and diversity. High intention by one of the most famous architects, Lord Norman Foster, is frequently applying the exposed spatial structural elements in his architectural design, as shown in Figure 2.6 (Bayat et al., 2014). By using space shear wall, the integration between structural and architectural elements can be improved and investigated on its challenges in high-rise buildings as demonstrated in Figure 2.5 (Sutjiadi ; Charleson, 2014). Therefore, space shear wall would be introduced as a compatible lateral resisting system for architectural considerations.

Sources: Sutjiadi ; Charleson, 2014

Figure 2.5: A Section of Three-Storeys Building Using Boundary Double-layer Space Structure

Source: Bayat et al., 2014

Figure 2.6: 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 storeys Project, Chicago e) Gakuen Spiral Tower, Nogoya f) Skytree Tower, Tokyo International

2.7 Lateral Load

Lateral loads are defined as the live loads in the form of horizontal force acting on the structure. Typical lateral loads would be a wind load against a facade, an earthquake, the earth pressure against a beach front, retaining wall or the earth pressure against the basement wall (Hoogendoorn, 2009). Most lateral loads vary in intensity depending on the buildings geographic location, structural materials, height and shape. The dynamic effects of wind and earthquake loads are usually analyzed as an equivalent static load in most small and moderate sized buildings (Brownjohn, 2015).

2.7.1 Wind Behaviour

Wind is a phenomenon of great complexity because of the many flow situations arising from the interaction of wind with structures. Wind has some negative and positive effects. For structural engineers, it always causes trouble with height (Lotfabadi, 2014). The average wind speed over a time period of the order of ten minutes or more, tends to increase with height (Mendis et al., 2007). Therefore, high rise building which is tall or slender, respond dynamically to the effects of wind. In Penang, an estimation of maximum wind speed at a building with height of 145.6m was conducted and indicated the value of 29.85 m/s (Deraman ; Chik, 2014). According to Malaysia Standard (MS1553:2002), the basic wind speed of Penang which categorised as Zone II is about 32.5m/s.

2.7.2 Wind Load

The principal lateral load this thesis is focused on the wind action. An introduction is presented to wind loading and wind-induced building response. It is tried to combine both wind engineering and the building code prescriptions (Hoogendoorn, 2009). The recommendations of Eurocode 1 are discussed and on occasion compared with the consulted literature on wind engineering (Hoogendoorn, 2009). Practically all building codes consider the wind action as a quasi-static load. To allow a static structural calculation, factors are introduced accounting for the spatial and temporal averaging of wind gustiness and the dynamic amplification of the building response (Patruno, Ricci, de Miranda, ; Ubertini, 2017). Eurocode 1 defines the wind load acting on any structure or element by: