WRITTEN REPORT

IN ARDES 8

Submitted by:

Cabrera, Rojen T.

Ogena, Alvin Jhon A.

Sumabong, Ezra Jerameel B.

Valdez, Gerardo M.

BS Architecture 4A

Submitted to :

Arch. Amelia Bautista

Professor

The term structural system or structural frame in structural engineering refers to load-resisting sub-

system of a structure. The structural system transfers loads through interconnected structural

components or members.

Commonly used structures can be classified into five major categories, depending on the type of primary

stress that may arise in the members of the structures under major design loads. However any two or more

of the basic structural types described in the following may be combined in a single structure, such as a

building or a bridge in order to meet the structures functional requirements.

Tensile structures: Members of tensile structures are subjects to pure tension under the action of

external loads. Because the tensile stress is uniformly distributed over the cross-sectional area of

members, the material of such a structure is utilized in the most efficient manner.

Compressive structures: Compression structures develop mainly compressive stresses under the

action of axial loads. Because compressive structures are susceptible to buckling or instability, the

possibility of such a failure should be considered in their designs if necessary, adequate bracing must

be provided to avoid such failures.

Trusses: Trusses are composed of straight members connected at their ends by hinged connections to

form a stable configuration. Because of their light weight and high strength, are among the most

commonly used type of structure.

Shear structures: These are structures such as reinforced concrete shear walls, which are used in

multistory buildings to reduce lateral movements due to wind loads and earthquake excitations. Shear

structures develop mainly in-plane shear with relatively small bending stresses under the action of

external loads.

Bending structures: Bending structures develop mainly bending stresses under the action of external

loads. The shear stresses associated with the changes in bending moments may also be significant

should be considered in their designs.

High-rise buildings

The structural system of a high-rise building is designed to cope with the vertical gravity loads and lateral loads caused by wind or seismic activity. The structural system consists only of the members designed to carry the loads, all other members are referred to as non-structural.

A classification for the structural system of a high-rise was introduced in 1969 by Fazlur Khan (3 April 1929 – 27 March 1982 was a Bangladeshi-American  structural engineer and architect, who initiated structural systems that form the basis of tall building construction today. Considered the Father oftubular designs for high-rise, Khan became an icon in both architecture and structural engineering. He was also a pioneer in computer-aided design (CAD) and helped in initiating the widespread use of computers for structural engineering. He is the designer of Willis Tower – the 2nd tallest building in the United States (and tallest in the world for many years) and John Hancock Center, a 100-story tall building, both in Chicago, Illinois. He also designed structures that are not high rises such as the Hajj Terminal. Khan, more than any other individual, ushered in a renaissance in skyscraper construction during the second half of the twentieth century and made it possible for people to live and work in "cities in the sky".Khan in his short life created a legacy of innovations that is without peer and left an unprecedented and lasting influence on the profession, both nationally and internationally. He has been called the "Einstein of structural engineering" and the "Greatest Structural Engineer of the 20th Century" for his innovative use of structural systems that remain fundamental to modern skyscraper construction. CTBUH named an award after him called Fazlur Khan Lifetime Achievement Medal. Khan's seminal work of developing tall building structural systems are still used today as the starting point when considering design options for tall buildings.)  and was extended to incorporate interior and exterior structures. The primary lateral load-resisting system defines if a structural system is an interior or exterior one.

The following interior structures are possible:

1)Hinged frame

2)Rigid frame - A rigid frame in structural engineering is the load-resisting skeleton constructed with straight or curved members interconnected by mostly rigid connections which resist movements induced at the joints of members. Its member can take bending moment,shear and axial loads.

3)Braced frame and Shear-walled frame - In structural engineering, a shear wall is a wall composed of

braced panels (also known as shear panels) to counter the effects of lateral load acting on a

structure. Wind and seismic[1] loads are the most common loads braced wall lines are designed to

counteract. Under several building codes, including the International Building Code (where it is called

a braced wall line) and Uniform Building Code, all exterior wall lines in wood or steel frame

construction must be braced. Depending on the size of the building some interior walls must be braced as

well. A more traditional method is to use let-in diagonal wood bracing throughout the wall line, and a

newer alternative is let-in metal T-bracing but these methods may not be viable for buildings with many

door and window openings and may not meet seismic or high wind zone codes.

The following exterior structures are possible:

1.Tube - In structural engineering, the tube is the system where in order to resist lateral loads (wind,

seismic, etc.) 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 Skidmore, Owings and Merrill's

(SOM) Chicago office. The first example of the tube’s use is the 43-story Khan-designed DeWitt-

Chestnut Apartment Building in Chicago, Illinois, completed in 1963.

The system can be constructed using steel, concrete, or composite construction (the discrete use of both

steel and concrete). It can be used for office,apartment and mixed-use buildings. Most buildings in excess

of 40 stories constructed since the 1960s are of this structural type.

John Hancock Center in Chicago , designed in 1965 and completed in 1969, is an example of the trussed tube structural design

The tube system concept is based on the idea that a building can be designed to resist lateral loads by

designing it as a hollow cantilever perpendicular to the ground. In the simplest incarnation of the tube, the

perimeter of the exterior consists of closely spaced columns that are tied together with

deepspandrel beams through moment connections. This assembly of columns and beams forms a rigid

frame that amounts to a dense and strong structural wall along the exterior of the building.

This exterior framing is designed sufficiently strong to resist all lateral loads on the building, thereby

allowing the interior of the building to be simply framed for gravity loads. Interior columns are

comparatively few and located at the core. The distance between the exterior and the core frames is

spanned with beams or trusses and intentionally left column-free. This maximizes the effectiveness of the

perimeter tube by transferring some of the gravity loads within the structure to it and increases its ability

to resist overturning due to lateral loads.

2.Diagrid - Diagrid (a portmanteau of diagonal grid) is a design for constructing large buildings

with steel that creates triangular structures with diagonal support beams.[1] It requires less structural

steel than a conventional steel frame. Hearst Tower in New York City, designed by Sir Norman Foster,

reportedly uses 21 percent less steel than a standard design. The Diagrid also obviates the need for large

corner columns and provides a better distribution of load in the case of a compromised building. Another

building designed by Sir Norman Foster, 30 St Mary Axe, known as "the Gherkin", also makes use of this

structural system.

British architect Ian Ritchie wrote in 2012, "... The origin of ‘diagonal’ structures is surely the Russian

genius Vladimir Shukhov. He pioneered new analytical methods in many different fields, and I have been

fortunate to visit some of his constructed projects more than once. Shukhov left a lasting legacy to early

Soviet Russia constructivism, and as the leading engineer and mathematician during the late 19th and

early 20th century he created hyperboloid, thin shell and tensile structures of extraordinary refinement

and elegance. ..."

The World's First Diagrid Hyperboloid structure in Polibino, Russia

3. Space Truss

4. Superframe

VERTICAL STRUCTURE SYSTEM

-Structure system which the main task is to collect loads from horizontal planes stacked upon one another and to vertically transmit them to the base, are vertical structure system.

-Characterized by the particular system of load collection, load transfer, and lateral stabilization.

-Vertical structure systems employ for redirection and transmittance of forces systems of form active, vector active, bulk active, or surface active mechanisms.

-Vertical structure system is solid rigid elements in predominantly vertical extension, secured against lateral strong and firmly anchored to the ground, can collect load from horizontal planes in high altitude above the ground and transfer them to the foundation.

- vertical structure system are instrument and order for the construction of high rise building, in thin capacity, they are codeterminant in shaping modern building and cities.

- vertical structure system require continuity of the elements that the load to the ground and hence concentrate congruency of the points of load collection for each storey. The distribution of land collecting points has to be determined not only by consideration of structural efficiency but also by those of floor utilization.

1. In the bay system – the collecting points are distributed over the whole floor plan.

A bay is a unit of form in architecture. This unit is defined as the zone between the outer edges of an engaged ('attached') column, pilaster, or post; or within a window frame, doorframe, or vertical 'bas relief' wall form.

Iglesia de San Sebastian Manila Cathedral 

2. In the free span system – the collecting points are arranged peripherally.

The State University of New York at New Paltz The Ramon Magsaysay Center (RMC)

3.In the cantilever system – the load collecting zone in centrally located.

The Cultural Center of the Philippines

BAY SYSTEM CANTILIVER SYSTEM FREE-SPAN SYSTEM

-Though suspension of the stories instead of their support, a sizeable reduction in the section of load- transmitting elements can be achieved. However, this indirect load transfer necessitates a super-imposed structural system for the final load transport to the ground.

Eco-Pod Vertical Farming Tended By Robots

Load are collected per area unit and individually led to the ground.

Load are in Center Load are transmitted to the external skin peripherally led to the ground.

SUSPENSION SYSTEMS IN VERTICAL STRUCTURES

-being economically section, the design of vertical structure system aims at the greatest possible reduction of load transmitted vertical elements in section and number.

-wind compression per area unit increases with building height. Its impact upon the structure becomes predominant in relation to that caused by verticals, the vertical structure is stressed by wind like a cantilevered beam is stressed by continuous vertical loads.

(CRITICAL LOADS AND DEFLECTIONS IN VERTICAL STRUCTURE SYSTEMS.)

(Additive and integral systems for transmission of wind loads.)

TENSION & COMPRESSION STRUCTURE SYSTEMS

- Carry loads by pure tensile or compressive stress

- Tents and cables need to be prestressed to stabilize

- Light, suitable to long spans and kinetic structures.

Tensile structures: Members of tensile structures are subjects to pure tension under the action of

external loads. Because the tensile stress is uniformly distributed over the cross-sectional area of

members, the material of such a structure is utilized in the most efficient manner.

Compressive structures: Compression structures develop mainly compressive stresses under the

action of axial loads. Because compressive structures are susceptible to buckling or instability, the

possibility of such a failure should be considered in their designs if necessary, adequate bracing must

be provided to avoid such failures.

TENTS AND CABLES

ANCHORS

PNEUMATIC STRUCTURES (foot ball field, Vancouver)

KINETIC STRUCTURE ( open-air theater by Otto) INSTANT CITY BY ARCHIGRAM GROUP

CONTROLLED ENVIRONMENT BY F. OTTO( MONTREAL WORLD’S FAIR)

FLOATING CITY BY W. CATAVOLOS