The Architect's Studio Companion Flashcards
___ are solid walls engineered to resist the effects of lateral forces.
Can be made of almost any structura material
Are stiff, and a good coirce for stablizing elements.
Shear Walls
Shear Walls:
To minimize interference with floor plan arrangements, shear walls are frequently incorporated into ____, ___ or ___ within the building.
Building cores,
Stair Towers
Vertical structures
Shear walls can also be part of the exterior wall, although in this location they limit access to ___
daylight and exterior views,
Composed of open triangulated frameworks
constructed of steel or wood
good in terms of strength per weight
most efficient lateral force stabilzing system
may be incorporated into the building core or other vertical structures
may be part of the exterior wall and may be come aesthetic element.
Braced Frames
Rigid Frames:
depend on stiffer and more difficult to construct column to beam connections, called _____
Moment connections
depend on stiffer and more difficult to construct column to beam connections, called moment connections
easily constructed with steel or sitecast concrete
Rigid Frames
The ___ is also the most structurally inefficient lateral force-resisting system. It is most suitable for low or broad structures requiring relatively modest resistance. In taller buildings, it is most frequently used in combination wit heither shear walls or braced frames.
Rigid Frame
Rigid frame introduces additional stresses into the strucural framework. This frequently results in coluns and beams that are ___ or in columns more closely spaced than would otherwise be requried.
heavier
___ connections, with intermediate stiffness, may also be used in combination wit hshear walls or braced frames, and at less cost than fully rigid moment conditions.
Semi-rgid connections,
Configuring Lateral Stabilizing Elements:
they must be arranged so as to resist lateral forces acting from all directions. This is usually accomplished by _________.
Alighting one set of stabilizing elements alogn each of the two major axes of the building.
also must be arranged in a balanced fashion
Configuring Lateral Stabilizing Elements:
Arrangements that displace the center of resistance away from the center of mass of teh building may lead to difficult-to-control movements or ______ under lateral load conditions.
excessive stresses
Configuring Stabilizing Elements:
lateral force-resisting elements are ____ and most extensive at the base of a building, and diminish in size and extent toward the top of the building. In addition, considerations of lateral stability become increasingly important as the ____ of the building increases. The Configuration of stabilizing elements is discussed further on the following pages.
Heaviest
Height and Slenderness
Stabilizing Elements should be arranged in a ____ fashion and to resist lateral forces from ____.
Balanced
Any direction
_____ are boards that function as framing elements in your home, supporting the walls. They’re spaced either 16 or 24 inches on-center (measured from center to center) along the wall and run between the floor and ceiling. Drywall or lath (for plaster walls) is attached to the edge of the studs.
Wood Stud Walls
Systems Well Suited to Wall and Slab Framing:
Wood Stud Walls
Cross-Laminaed Timber
Brick Masonry Walls
Concrete Masonry walls
Lightweight Steel Stud Walls
Sitecast Concrete Walls
Precast Concrete Wall Panels
_____ is a wood panel product made from gluing layers of solid-sawn lumber together. Each layer of boards is oriented perpendicular to adjacent layers and glued on the wide faces of each board, usually in a symmetric way so that the outer layers have the same orientation.
Cross-laminated timber
_____ are the most durable part of any building or structure. … Masonry is the word used for construction with mortar as a binding material with individual units of bricks, stones, marbles, granites, concrete blocks, tiles etc. Mortar is a mixture of binding material with sand.
Brick Masonry walls
_______ (or as it is more commonly called, concrete blockwork) is based on thousands of years experience in building structures of stone, mud and clay bricks.
Concrete masonry construction
As opposed to precast, _____ , is poured, molded and cured on site. Like precast concrete, on site concrete is formed in a mold and then lifted in place. However, one of its advantages over precast slabs is that it does not need to be moved far to be lifted into place.
site cast, sometimes known as in-situ concrete
_____ is a construction product produced by casting concrete in a reusable mold or “form” which is then cured in a controlled environment, transported to the construction site and lifted into place (“tilt up”). … Precast is used within exterior and interior walls.
Precast concrete
Shear walls may be arrange in a ____ to resist lateral forces from all directions.
box form
In wall and slab systems, the distance between walls is _______ . Openings in walls may be made when beams are added to carry loads from above.
Equal to the span of the slab above.
Bearing walls may act as _____ to span openings below, as shown in this schematic cross section.
deep beams
Bearing wall and column systems may be combined for _____ in plan layouts.
more flexibility
_____ systems are composed of vertical columns, horizontally spanning girders and beams, and slabs spannign the area between the beams.
Compared to wall and slab systems, this system palce fewer constraints on the organization of space.
Column and Beam Systems
Column and beam systems of steel frame or sitecast concrete construction are well suited to act as ____ for some or all of the structure’s lateral force resistance.
rigid frame
In _____, beam to column moment connections are usually easily produced as a normal feature of the system.
Sitecast Concrete
Moment connections are most difficult to construct and less frequently used in ____ structures.
Precast concrete
Rigid frames are normally not well suited for structures with _____
UNusually long spans or tall, slender columns.
Deeper beams, termed ____, span the columns.
In turn, support shasllower secondary beams, spannign perpendicular to them.
Girders
In column and beam systems, columns are located on ___.
Beam Lines
Beams span ____ in beam and girder systems
both directions
_____ systems are composed of vertical columns directly supporting horizontally spanning slabs without intermediary beams.
Column and Slab Systems
The absence of beams in column and slab systems may permit even _____ in column placements that with column and beam systems, because columns are not restricted to beam lines.
Greater flexibility
Most column and slab systems are constructed of _____.
Sitecast concrete
Rigid frame action is sometimes possible in column and slab systems, although its effectiveness depends on the ____ of the slab, particularly in the areas close to the columns.
Depth
Systems well suited to column and Slab Framing:
Site Cast Concrete Two Way Flat Plate
Sitecast Concrete Two way Flat Slab
Sitecast Concrete One-way Joists
Sitecast COncrete Waffle Slab
The most iconic site cast concretesystem is the _____. Preformed pans are used to create a form that casts the concrete into a wafflepattern
waffle slab
___ are frequenly used with column and slab systems to provide greater resitance to lateral forces. In this elevation and plan, the shear walls are shown incorporated into a pair of vertical cores.
Shear walls
Column and Slab system layouts
Column spacing either direction is equal to the span of the slab. For maximum economy and structural efficiency, column bays should be roughly ___ in proportion and columns should be arranged along regularly spaced bearing lines.
Where driven by design considerrations column and slab systems can tolerate deviations in standard column placements, variations in bay sizes and _______
Square
irregular plans shapes
Structural Limitations of Column and Slab Systems:
The relatively shallow depth of the joint between the columns and slabs can _____ and limit their resistance to lateral forces.
restrict their vertical load -carrying capacity.
Define Flat Slab
two way reinforced structural system
Has Drop panels or Column capitals to prevent punching shear
Define Flat Plate
Two way reinforced framing system
The absence of beams in column and slab systems facilitates _____ layouts or plan shapes.
Irregular column
Tall Building Structures:
In the tallest buildings, ______ are msot common due to their efficient use of space, sturctural versatility and ease of construction.
Column and beam, or column and slab
Tall structures, to the greatest extent possible, building core structures, columns and other loadbearing elements should extend ____ to the foundation and should avoid offsets from floor to floor or other discontinuities.
continuously
Tall Building Structures:
Where more significant redistributions of load are required, ____ or ____ structures may be used. In other cases, changes in the selection of structural system or its basic configuration and design may be appropriate.
Transfer Beams
Heavy Long-Span Truss
Tall Building Structures:
In the tallest building, structural design is driven foremost by resistant to ____, more so than either gravity loads or lateral earthquake forces.
Wind Loads
Tall BUilding Structures:
An open space with long horizontal spans at the base of a tall building can produce excessive flexibility or weakness at that level. If such a ___ cannot be avoided, extra effort to provide adequate lateral support at that level may be required.
Soft Story
Tall Building Structures:
____ can cause oscillation or twisting of the building structure, lateral accelerations that are uncomfortable for occupants, or localized areas of high pressure acting on the facade.
Wind Forces
Tall Building Structures:
Discrete building masses should be structurally ____. INherently unstable buildin masses should be avoided.
independent
Tall Building Structures:
_____ in the stiffness of structures at different levels should be avoided, or additional stabilizing elements may be requried.
Discontinuities
Tall Building Structures
Conventional Structural Configurations:
The conventional arrangements of stabilizing elements used in low-rise buildings may be extended for use in buildings up to ____ stories in height. Stabilizing elements should be arranged so as to resist lateral forces along all major axes of the building.
20 - 25
Tall Building Structures
Conventional Structural Configurations:
___ and _____ are the stabilizing elements most common used in buildings of this height due to their structural efficiency. They may be used either separately or in combination.
The use of rigid frams systems as the sole means of achieving lateral stability may be feasible in buildings up to ____ stories in height in areas of low seismic activity.
Shear walls and braced frames
15 - 20
Tall Building Structures:
Core Structures:
One of the principal advantages of core structures is that with the placement of the resisting elements in the _____, interference wit hthe remainder of the floor plan is minimized.
building core
Core Structures:
In concrete construction, core walls already intended to enclose building systems can easily be designed to also act as ____. In steel construction, core structures are usually designed as ____.
Shear walls
Braced Frames
Core Structures:
A single core servicing an entire building shouldbe located at the ___ of the building. In building with more than one core, the cores should be located ____ in the building plan so as to provide balanced resistance under lateral loads from any direction.
center
symmetrically
Core Structures:
Cores typically comprise approximately ____ of the floor area of a mid or high rise building. They should be formed as closed elements, approximately square or cylindrical, with openings into the core kept to a minimum.
20 - 25%
Core Structures:
Simeple core structures can be used in buildings as high as ____ stories.
35 - 40 stories
Core Structures:
Core structures can also be enhanced structurall with ____ (at top of the structure) ir ____ (at points lower down) that engage the perimeter’s structural elements in the resistance to lateral loads, thus improving the performance of the building as a whole.
These elements may be aesthetically expressed on the building facade or serve as preferred locations for dedicated mechanical floors. Columns at the perimeter of the building may also increase in size with these systems. These core-interactive structures are suitable for buildings up to approximately ___ stories in height.
hat trusses
belt trusses
60
In structural engineering, the ____ is a system where, to resist lateral loads, a building is designed to act like a hollow cylinder, cantilevered perpendicular to the ground. This system was introduced by Fazlur Rahman Khan while at the architectural firm Skidmore, Owings & Merrill, in their Chicago office.
Tube
Tube Structures:
Many of the world’s tallest buildings are designed as ____. IN this system, stabilizing elements are located at the ____ of the structure, leaving the layout of the interior of the building unrestricted by considerations of lateral stability.
Tube structures
perimeter
Tube Structures:
Simple tube structures and their variations are generally suitable for buildings approximately ___ stories or greater in height.
55
Tube Structures:
When building in steel, the welded joints requried in this system may be more sostly to construct, although systems taht allow the ___ fabrication of these joints acan minimize this disadvantage.
off site
Tube Structures:
As with core structures, the performance of rigid frame tubes may be enhanced with ____ or ___ integrated within the perimeter structure.
hat trusses or belt trusses
Tube Structures:
_____ tubes are highly structurally efficient lateral load-resisting configurations. When built in steel, these structures rely on more easily constructed hinged connections. The diagonal braces that are an integral part of this system often have a significant impact on the appearance of the building facade.
Braced frame
Tube Structures:
_____ structures allow perimeter tubes to interact with rigid cores.
Tube-in-tube
Tube Structures:
___ structures allow greater variation in building massing.
Bundled tube
Tube Structures:
_____ structures are similar to braced tubes, with the addition of large-sacale diagonals that pass through the building’s interior.
Space Truss
Tube Structures:
____ rely on latticed framworks that carry both vertical and lateral loads, with few or no vertical columns.
Diagrid Structures
Pratical Limits on the Height and Slendernes of Tall Buildings
At the time of this writing, the world’s tallest building is Dubai’s Burj Khalifa Tower, with ___ occupied floors and a height of _____. For most of its height, this building constructed as a ____, wall and slab structure. Lateral stabiity is provided by a central concret ecore buttressed by heavy shear wall radiating toward the tower extremities. This buttressed core design is considered practical for buildings_____ tall or greater. Looking to the future, buildings up 3280 ft (1km) in height are reportedly instages of planning or early construction.
163
828m
sitecast concrete flat plate
Pratical Limits on the Height and Slendernes of Tall Buildings
Typical tall commercial and mixed-use buildings have slenderness ratios (ratio of height to least plan dimension at the base) in the range of ____. For example, the burj Khalifa is 9 times as tall as it is wide at its base.
5 - 10
Pratical Limits on the Height and Slendernes of Tall Buildings
On constrained, high-value urban sites, residential towers with slenderness ratios of ___ or higher have been constructed. The 111 West 57th Street residential tower in New York City is at this time, one of the world’s most slender tall buildings, approximately ____ in height and 23 times tall as it is wide.
15
440m
Architect of 111 West 57th Street Residential Tower
Shop Architects
composed of 4 principals
111 West 57th Street Residential Tower in NEw York by SHoP Archtiects
Special Considerations in The Design of Tall Structures:
Steel Structural Systems
____ also has particular advantages for buildings located in areas of high seismic activity. A lower-mass structure experiences lower forces during an earthquake.
Structural Steel
Special Considerations in The Design of Tall Structures:
Concrete Structural Systems
In comparison to structural steel, ___ is a more massive and less ductile material. For these reason, it has traditionally been considered to be at a disadvantage for the design of tall buildings.
concrete
Special Considerations in The Design of Tall Structures:
Concre’s unique characteristics can also offer advantages. ___ is tough and resistant to impact, nd unlike steel, it usually does not require a separate covering to protect it from the heat of building fires.
Concrete
Special Considerations in The Design of Tall Structures:
Composite columns made of steel box hapes filled with high strength concrete can achieve very high load-carrying capacity. Such composite columns form a primary structural element in one of the world’s tallest buildings, the _____. At the base of this building, each of eight “supercolumns” measures almost 8 x 10 (2.4 x 3m) in section. Even in building structures nominally described as steel, concrete-core structures and floor systems common play essential roles as well.
Taipei 101
Damping MEchanism for Resisting Lateral Forces
A tall building structure;s response to the effects of wind or earthquake can be effects of wind or earthquake can be enhanced with devices designed to dampen the movements imparted to it by these loads. _____ dampers are shock-absorber like devices. They may be incorporated into parts of the building frame, where they can reduce building deflections during high lateral loading as well as increase the structure’s energy-absorbing capacity.
Viscous Dampers
Viscous dampers may also be combined with a system of ____ at the foundation of the building. This arrangement allows a degree of separation between the building structure and the ground upon which it rests. In the event of an earthquake, a significant portion of teh ground motion that occurs is never transmitted into the building structure at all.
Base Isolators
Damping Mechanisms for Resisting Lateral Forces:
____ may be used to control deflection or “side sway” in tall buildings. These are heavy masses, suspended, pendum-like, within the building structure, usually near its top and connected to it by an array of dampers similar to those discussed above.
AS wind forces act to deflect the structure sideways, the inertial of the suspended mass resists theses movements and erduces the magnitude of the sdideways deflection.
Tuned mass dampers
Damping Mechanism for Resisting Lateral Forces:
More recently, ____ dampers consisting of water tanks with specially configured internal chambers and baffles have been designed to work in a similar manner. The water stored in these tanks can also serve as emergency supply for the building’s fire suppression systems.
Tune Liquid Dampers
___ dampers relu on sensors place near the top of the building structure that measure accelerations in real time This information is processed and then used to command hydraulic activators that exert counteracting forces on portions of the structure, thereby limiting structure movements.
Active Dampers
____ damer systems may not be suitable for use in areas of high seismic activity, where lost of power during earthquakes could render the system inoperable.
Such dampening systems can be useful in very tall buildings where the discomfort caused by building sway frequently becomes the controlling factor in the structural design.
Active Damper
Viscous Damper define
Same mechanism used in car shock absorber
Hydraulic device that has viscous fluid to releast heat and accept lateral forces
Base Isolators define
A cylindrical like damping device that works in a swinging motion, located primarily atthe foundation of the structure.
_____ timber, also called___ , is a type of structural engineered wood product comprising a number of layers of dimensional lumberbonded together with durable, moisture-resistant structural adhesives. In North America, the material providing the laminations is termed laminating stock or lamstock
Glued laminated
glulam
In structural engineering, the _____ is a lightweight steel truss consisting, in the standard form, of parallel chords and a triangulated web system, proportioned to span between bearing points
Open-Web Steel Joists
