Multi-storey buildings

Transcription

1 Doc. Ing. Hana Gattermayerova,CSc Contents Multi strorey buildings Sources, literature Definition Features Statical systems Interior Extrior Materials Hájek P. a kol.: Konstrukce pozemních staveb 1 Nosné konstrukce I, skriptum ČVUT, Praha 2006 Ching, F.: Building structures illustrated ructural-engg/high-risestructures/5/

2 Definition Definition 10 stories or more or 30 m (100 feet) more Various definition: Buildings between 23 m and150 m high are considered high-rises. Buildings taller than 150 m are classified as skyscrapers.

3 Definition Definition of high-rise building (Council on Tall Buildings): A tall building is not defined by its height or number of stories. It is a building in which tallness strongly influences planning, design and use. The height of this building creates different conditions in the design, construction, operation...

4 Definition Fire definition Certain height above the lowest level of fire department vehicle access (Building Code, ČSN ) ČSN Požární bezpečnost staveb Společná ustanovení Fire protection of buildings General requirements ČSN Požární bezpečnost staveb -Fire protection of buildings Non-industrial buildings

5 Definition fire height (ČSN) hp: floor hp < 12 m hp 12 m < hp 22,5 m hp > 22,5 m basement

6 Feature office building residential buildings multi-functional buildings

7 Statical systems High-rise buildings are dividing into two categories, based on the dominant location of the vertical lateral - resisting systems: Interior Structures Exterior structures

8 Statical systems Interior Structures Interior Structures resist lateral load primarily through lateral-force-resisting elements located within the interior of the structure interior elements are constructed into a closed system that acts as a structural tube Types of interior structures: Rigid frame Braced frame Shear wall core Rigid frame Braced frame cores Shear wall cores

9 Statical systems Interior Structures Recomended number of Stories

10 Exterior Structures Resist lateral load primarily through lateral-force-resisting elements located along the perimeter of the structure Types of interior structures: Braced frames Tube structures Tube-in-tube Structures Diagrid Structure Trussed Tubes Bundled Tubes Space Truss Megaframe Structures Braced Frames Tube Structures Tube-in-tube Strucrures

11 Diagrid Structure Trussed Tubes Bundled Tubes Space Truss Megaframe Structures

12 Recomended number of Stories

13 Rigid Frame Structure Consist of columns and girders joined by moment resistant connections. Lateral stiffness of a rigid frame bent depends on the bending stiffness of the columns, girders, and connection in the plane of the bents. Ideally suited for reinforced concrete buildings because of the inherent rigidity of reinforced concrete joints. Also used for steel frame buildings, but momentresistant connections in steel tend to be costly. Buisness Men s Assurance, Kansas City, USA

14 Advantages of rigid frames: May be place in or around the core, on the exterior, or throughout the interior of the building with minimal constraint on the planning module. The frame may be architecturally exposed to express the grid like nature of the structure. The spacing of the columns in a moment resisting frame can match that required for gravity framing. Bank, Kasas City, USA

15 Disadvantages of rigid frames: Only suitable for building up to stories only Member proportions and materials cost become unreasonable for building higher than that. Vince's St. Louis, USA: B131 - Drury Plaza Hotel. Built with the seldom used Vierendeel truss system creating a rigid steel frame expressed in a stainless steel grid

16 Braced Frame Structures Braced frames are cantilevered vertical trusses resisting laterals loads primarily through the axial stiffness of the frame members. The effectiveness of the system, as characterized by a high ratio of stiffness to material quantity, is recognized for multi-storey building in the low to mid height range. Generally regarded as an exclusively steel system because the diagonal are inevitably subjected to tension for or to the other directions of lateral loading. Able to produce a laterally very stiff structure for a minimum of additional material, makes it an economical structural form for any height of buildings, up to the very tallest.

17 Advantages of braced frames Girders only participate minimally in the lateral bracing action-floor framing design is independent of its level in the structure. Can be repetitive up the height of the building with obvious economy in design and fabrication. Disadvantages Obstruct the internal planning and the locations of the windows and doors; for this reason, braced bent are usually incorporated internally along wall and partition lines, especially around elevator, stair, and service shaft.-diagonal connections are expensive to fabricate and erect.

18 Statical systems Exterior/Interior Structures Shear Wall Structure Concrete or masonry continuous vertical walls may serve both architecturally partitions and structurally to carry gravity and lateral loading. Very high in plane stiffness and strength make them ideally suited for bracing tall building. Act as vertical cantilevers in the form of separate planar walls, and as non-planar assemblies of connected walls around elevator, stair and service shaft. Well suited to hotel and residential buildings where the floor-by floor repetitive planning allow the walls to be vertically continuous and where they serve simultaneously as excellent acoustic and fire insulators between rooms and apartments.

19 Statical systems Exterior/Interior Structures Shear Wall Structure Tensile reinforcement for areas where tension stresses occur in walls when wind uplifts stresses exceeds gravity stresses. Individual shear walls, at the edge of a tall building, are design as blade walls or as columns resisting shear and bending as required. High strength concrete has enable wall thickness to be minimized, hence maximizing rentable floor space. Burj Dubai, Dubai, Arab Emirates

20 Diagrid structure Is a design for constructing tall buildings with steel that creates triangular structures with diagonal support beams. It requires less structural steel than a conventional steel frame. Jean Nouvel: 53 West 53rd, NY Norman Foster: 30 St Mary Axe, London, UK

21 The Trussed tube The trussed tube system represents a classic solution for a tube uniquely suited to the qualities and character of structural steel. Interconnect all exterior columns to form a rigid box, which can resist lateral shears by axial in its members rather than through flexure. Introducing a minimum number of diagonals on each façade and making the diagonal intersect at the same point at the corner column. Relatively broad column spacing can resulted large clear spaces for windows, a particular characteristic of steel buildings. John Hancock Building, Chicago, USA

22 The Trussed tube The Onterie Center in Chicago interpreted the trussed-tube structural system for reinforced concrete construction.

23 Space truss The Hong Kong Bank of China Tower has an externally visible truss structure. The whole structure is supported by the five steel columns at the corners of the building, with the triangular frameworks transferring the weight of the structure into these five columns. It is covered with glass curtain walls. Bank of China, Hong Kong Bank_of_China_Tower_model.png

24 Tube-in-Tube or Hull Core Structure This variation of the framed tube consists of an outer frame tube, the Hull, together with an internal elevator and service core. The Hull and core act jointly in resisting both gravity and lateral loading. The outer framed tube and the inner core interact horizontally as the shear and flexural components of a wall-frame structure, with the benefit of increased lateral stiffness. The structural tube usually adopts a highly dominant role because of its much greater structural depth. Tabung Haji Building, Designed by Hijas Katsuri, Kuala Lumpur, Malaysia

25 Bundled-Tube structures The concept allows for wider column spacing in the tubular walls than would be possible with only the exterior frame tube form. The spacing which make it possible to place interior frame lines without seriously compromising interior space planning. The ability to modulate the cells vertically can create a powerful vocabulary for a variety of dynamic shapes therefore offers great latitude in architectural planning of a tall building. Sears Tower Chicago, USA

26 Sears Tower bundled tube The building is constructed of nine 75-footsquare tubes of welded steel that extend between 50 and 108 stories high. Floors are suspended within the tubes.

27 Megaframes Structures The structural efficiency is obtained from the concentration of material close to the corners. Each of these vertical legs is required to be stiff in its own plane. The legs then take the form of a diagonalized truss chord. The corner truss legs need strong horizontal connections at frequent modular intervals to make them function together like an equivalent cantilever. The horizontal members, therefore, will need to be equally stiff, and are diagonalized as well.

28 - Materials The materials used for the structural system of high-rise buildings are reinforced concrete and steel. Most skyscrapers have a steel frame, while residential buildings are usually constructed out of concrete. Steel Drawn steel sections

29 - Materials Concrete in-situ concrete moving formwork (posuvné) permanent formwork (ztracené)