Light Thread

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A. Design Concept

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A-1

■Light Thread

"Light Thread" forms this architecture.

"Light Thread" symbolizes a pulse of multiple lives. This innovative idea brings a completely new architectural form by its lighting and illuminating effect and by its construct method, which nobody has ever seen in the world. “Light Thread” is cut out three-dimensionally from a rectangular concrete body. This quite rational, beautiful, simple and strong method creates architecture economically.

 

A-2

■Forest

This architecture is a forest.

“Light Thread” covers the whole architecture. According to a lighting condition, some “Light Thread” makes an area of ceramic printed glass with various characteristic patterns on it, which introduces sunlight to inside. It seems as like a nature wraps the architecture in grass with its flowers and fruits. Its complex appearance reminds an eloquent life of plants. We can find an amazingly eloquent light from there. As like a light in forest this architecture is luxuriance.

 

A-3

■Light Wall

This light wall functions as a structural wall.

The dynamic “Light Thread” on this architecture is made by a flat bar type steel that fits within a wall thickness of 400mm. It composes a very stable triangular lattice with sewing the slit. By this method “Light Thread” forms wall structure with keeping flexibility of direction. And it enables to realize various design of the slit in a huge architectural scale. This structural system is a very unique one in the world.

 

A-4

■Leafscape

A landscape of this architecture is soils, roots and water, which bring up a forest, that is to say earth. It is abstracted “Leaf” which comes down on the earth.

The landscape of abstracted “Leaf” becomes a center of the east campus. According to the master plan concept of the campus of China Agricultural University, high-rise buildings areas are arranged on the perimeter of the campus. Therefore, the roof and the landscape of this architecture can be seen well from the high-rise buildings. Beautiful scenery of “Leafscape” in the east campus with beautiful woods of gingko, maple tree, white birch and oak etc. in a image of the forest mingled in the universal rectangle shaped architecture is in harmony with a shine on 小月川 river.

 

A-5

■Luminous Structure

“Light Thread” over this architecture is a light tube.

“Light Thread” leads a daylight to the interior space, which is as like a play of sunlight through the trees. In the night it radiates light by a progressive light-up system. The light tube reminds a physical motion pulse of wrestling games. It glows as a luminous structure, namely lighting wire frame.

 

■Gymnasium with Four Fields

This architecture is a gymnasium of “4 + 4”.

There are four arenas and four halls inside. Four arenas are namely a main arena, a sub arena, a swimming pool and a martial arts arena. Four halls are namely a dance studio, a training room, a music room and a conference hall. The architecture has an universal rectangular plan. It enables a rational coordination between various functions during the Olympics and the Paralympics economically. And also, it will realize long life facility usability as a proud Cultural Gymnasium of China Agricultural University. Moreover, almost of the arenas and the halls locate on ground floor level, which enables to use the gymnasium together with outer playground.

 

A-6

Innovative form by “Light Thread”

■Innovative Façade by “Light Thread”

This architecture has an abstract form with random crossing curves on a rectangular body.

Its façade has a dynamic, unique and amazing strong ness.

With its strong ness a lithe form of “Light Thread” symbolizes a feeling of plant’s life growing from a ground to a sky, a pulse of sports and an energy of the Olympics, which reminds an image of a dynamism, a growth, a development and a breakthrough of China in future.

 

■Dramatic Interior Space

“Light Thread” creates a dramatic space with a calm and tender daylight crossing inside. The interior space of this architecture is luxurious as like a forest with the play of sunlight through the trees.

 

■Form inspiring Imagination

 “Light Thread” is an abstract form, which inspires various imagination.

This form expresses a feeling of plants’ life and a physical motion of athletes. At the same time it realizes a symbolic character as a facility for the Olympics and also as a main facility of China Agricultural University. 

 

A-7

Imaginings by curvy slits 1

■Image of Forest

 “Light Thread” expresses the pregnant working of nature in four seasons.

-The sprouts, the fresh green, the murmur of a stream, the birds on trees and the butterflies in spring.

-The fruits, the blooming trees, the fluttering leaves, the clouds at dusk, the fairly, the plenty of bunches and the fern in summer.

-The red leaves, the ears of rice, the beans, the color of red and yellow, the variety of shade, the copious crops, the fields, the falling leaves and the mushrooms in autumn.

-The groves, the ivies, the beaches, the rainy nights, the snow, the mist, the fog, the stars, the crystals, the bulbs, the roots in winter.

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Imaginings by curvy slits 2

■Image of Plants

This architecture is a tube thrusting up toward the sky.

The form of this architecture expresses a power welled from the earth and the roots. A bounding power of the plants growing up from the earth into the sky. A tube thrusting up toward the sky. Bounding China. China thrusting up from the earth toward the sky. Besides having a stable base, this form has an origin in plants, which roots have a strength to grow taking root in the earth, which sprout in great force, and which thrust spontaneously up toward the sky.

 

A-9

Imaginings by curvy slits 3

■Image of Sports

“Light Thread” expresses a feeling of pulse in the wrestling games. Besides the wrestling games, “Light Thread” expresses various sports of the Olympics.

It shows a sketch of the pulse of various sports, such as a step of dance, strength in athletes’ leg, swimming, badminton, volleyball, basketball, tennis, a swing of table tennis, jumping, flying, biceps, stretching and limber ness of the martial arts.

 

A-10

Imaginings by curvy slits 4

■Image of Wresting

A conception origin of “Light Thread” is in holds of wrestling and its physical motion.

To create monumentality as a wrestling arena for the Olympics, this architecture abstracts a physical motion, intertwining arms, legs and bodies of wrestling games. A power of this great wall with “Light Thread” functions as a structural wall that memorializes the Olympics wrestling arena.

 

B. Structure System

 

B-1

Structure System 1

■"Thin-walled spatial structure" with the three-dimensional effect

　This architecture has "Thin-walled spatial structure"

 "Light Thread" runs over the whole architecture randomly. The exterior wall of the architecture seems to be cut in pieces. But "Light Thread" stitches up the exterior wall as one structural body.

The roof is made from a concrete as same as the wall, so that "Light Thread" can wrap over the whole architecture continuously. It enables the three dimensional expansion of "Light Thread"

Four sides of the exterior wall, ground and roof establish a structural characteristic (three dimensional effect) as one solidified body. By this effect the architecture can be realized by a quite thin, light and reasonable structural body.

　

■"Semi-rigid parabolic truss" optimizing the three-dimensional effect

The biggest structural span of this architecture is 144×90m. A vertical structural element to support this large space is nothing but the wall of "Thin-walled spatial structure" We adopt "Semi-rigid parabolic truss" optimizing a rigidity of four sidewalls, so that the roof span of 90m can be realized efficiently and economically.

"Semi-rigid parabolic truss" is composed of concrete slabs to share a horizontal rigidity and a parabolic truss to share a roof load.

 

B-2

Structure System 2

■Structure of "Light Thread"

"Light Thread" is made up by a flat bar type steel that fits within a wall thickness of 400mm, which stitches up a triangular lattice. The lattice components are anchored in a concrete. The anchor plate covers wall headers of "Light Thread" which is used also as a formwork plate to improve construction efficiency.

 

■Structural Design for Swift Construction

This architecture is designed considering a swift construction.

The wall of "Thin-walled spatial structure" and interior skeleton are made of cast-in-place concrete. The roof beams are made of steel. Therefore, a production of shop drawings for a steel work and a fittings work a manufacturing in factories can be done during a construction period of cast-in-place concrete. The construction period can be used quite efficiently to contribute to a perfect preparation for the Olympics.

 

■Economy by the three-dimensional effect

A utilization of the three-dimensional effect by each structural component contributes to design a long span structure economically.

The structure design of this architecture is considered that. We optimize a big stretching rigidity of structural planes (roof and walls) that are arranged on different directions effectively, so that the three-dimensional effect can work to increase economical efficiency.

 

 

C. Conversion

 

Conversion

■Universal

The planning of this architecture is based on a simple rectangular, so that it is easy to convert interior space into other functions. It is a universal design.

Its simple rectangular planning fits justly with a characteristic of a wrestling court, moreover of a swimming pool and of rectangular court for sub arena. There is no lost space in this planning. It enables easy functional conversion after the Olympics. And it economically realizes a various usage as a multifunctional gymnasium after the Olympics.

 

 

■Economy, Construction Efficiency

A rectangular body of this architecture optimizes efficient use of the whole interior space.

Grand planning achieves a high possibility to realize this architecture by reducing an underground volume and by an efficient cost planning with rationalized structural spans and so on. It enables to realize a unique and symbolic character of this architecture within a remitted total budget. 

 

■Rectangular Body

Though this architecture has a compact rectangular body, it realizes an absolutely new landscape with “Light Thread” over it.

With curvy slits on its rectangular volume of 144mx90mx19m this architecture matches with the neighbor campus buildings in view of a far distance. And also it realizes a powerful symbolic character in view of a near distance.

 

■Three Dimensional Figures in Rectangular Body

This architecture is quite unique in its characteristic “Light Thread” that spreads randomly from wall to roof, from roof to wall and from wall to wall. This architecture creates completely new space, which has never been found in the simple box architectures yet completed.

 

D. Landscape

 

Landscape: View in Far Distance

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■Five Sides Facade

The project site locates in the center of east campus of China Agricultural University. In east campus, high-rise buildings are planed to be built on the perimeter, and low-rise buildings are planed to be built in the center. This architecture is “visible” from five directions, such as east, west, south, north and from above.

Therefore, this architecture prepares beautiful façades of “Light Thread” on east, on west, on south, on north and on the roof.

 

■“Leafscape”

In front of this architecture we design “Leaf Plaza” as a new central plaza of the campus. The project site for this architecture locates in a high densely campus area. It is quite important to achieve a good continuity of architectural design between the surroundings and this gymnasium. “Leafscape” design method of this project enables that.

“Leafscape” is a landscape design using a motive of abstract curvy line patterns as same as the wall and the roof of the architecture. “Leafscape” is formed of a pattern of big arcs. This pattern expresses “leaves” fell on the earth.

 

Landscape: View in Near Distance

■Continuity of the Whole Campus by “Leafscape”

The groves in the campus are abstracted in the design of “Leafscape”.

Beautiful grove scenery with ginkgoes, maple trees, white birches and oak trees in the east campus is re-created as a contemporary landscape in this site.

 

■Promenade to the river

 “Leafscape” shapes a promenade to the river. “Leafscape” makes small water ponds dotted in the site. Its landscape lays next to the river with a symbolic foretaste of the surface of the river. It is elegant as like leaves floating on the water softly.

“Leafscape” is designed to show off the grove and nature in the campus. It snuggles to the luxuriance of the architecture that is wrapped with an image of the forest. At the east side of this gymnasium the center area of outer playground track have a “leaf” shaped shrubbery. This will remain as memorial trees for the Olympics after the Olympics is closed.

 

■Materials, Outer Playground

“Leafscape” carves cuts on the ground, which are the abstracted image of water, grasses, stones and earth. The ground cuts with an image of “Light Thread” have different kind of stone in a width of 500mm. “Leafscape” extends its design concept also to the outer playground at east side of the architecture. We plan the outer playground with respecting a nature environment.

 

■Sense of Unity with the Ground

“Light Thread” introduces a sunlight and a natural wind into the rectangular body. Many of curvy slits continue from the roof to the ground. People next to the wall will find that the interior space is see-through from outside, and that the exterior space is see-through from inside on the other hand. The slits unify the interior and the exterior of this architecture.

 

Light

■Forest

This architecture is a forest of light and shadow.

“Light Thread” is figured by light and shadow. Treasured light in this architecture is as like a light through a forest and as like a light through leaves. And this architecture releases the treasured light.

 

■Lighting Control System

This architecture becomes a wire frame of light.

“Light Thread” over this architecture is a tube of light. During the daytime it introduces sunlight to the interior space, which is as like sunlight in the forest through trees. During the nighttime the slits radiate light by using a progressive light-up system. The architecture becomes luminous body with various lighting equipments, such as diffusive lightings on the concourse ceiling, high brightness lightings with highly color rendering function in the bottom of the slits, upper lights on the exterior wall and “luminous painted” metal plates on the header of the slits.

 

Shadow

■Design of Shadow in Landscape

This architecture increases its variety of the lighting effect together with “Leafscape”.

The light through the slits on the architecture figures shadow on the landscape of “Leaves”. The stone-finished landscape reflects the shadow clearly. A design of the wall slits is equal to a design of the landscape. The shadow by the slits of the architecture wavers on the curvy lines of “Leafscape”. The shadow on different types of stones and water body is colored in a character of exotic art.

 

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E. Structure outline

 

E-1

Structure outline 1

■Analysis and description of the structure sizing

This building has the length of 142m in north - south direction, width of 90m in east- west direction, and the height of 19m.

This building consists of two floors above ground and one basement floor.

Reinforced concrete rigid frame structure with earthquake resisting wall (basic grid:8mx8m) is adopted for the internal space, thin-walled spatial structure of reinforced concrete for the outer wall, and Semi-rigid parabolic truss (it is 6m pitch at SPAN 90m) which combines reinforced concrete and steel structure for the roof.

These applied structural systems have rationality as well as economical efficiency.

 

■Aseismic design of structures

Reinforced concrete rigid frame structure with earthquake resisting wall (basic grid:8mx8m) is adopted for the internal space.

This structural system is effective against earthquake, and secures high earthquake resistance by locating the earthquake resisting wall with balance.

The earthquake resisting wall is located rationally, structurally and economically by considering the reconstruction.

Thin-walled spatial structure of reinforced concrete is adopted for the outer wall.

Semi-rigid parabolic truss (it is 6m pitch at SPAN 90m) which combines reinforced concrete and steel structure is applied to the roof.

The structural elements have very large in-plane stiffness as a plate.

High seismic resistance of the building skin is realized by the combination of those elements in three dimension.

 

■Sizing of roof structures

Semi-rigid parabolic truss (it is 6m pitch at SPAN 90m) which combines reinforced concrete and steel structure is applied to the roof.

The Semi-rigid parabolic truss has span of 90m in east - west direction, and pitch of 6m in north -south direction.

Since the structure which supports the roof is a wall (continuous), the location of this truss will not be influenced by the basic grid in internal space.

Therefore, the pitch of a roof truss can be determined rationally and economically.

 

E-2

Structure outline 2

■Application of new structure

Two new structures are proposed in this building.

One is the "Thin-walled spatial structure" of the exterior wall. Reinforced concrete wall structure which consists of no particular column or beam is combined with "Light-Thread" in this new structure. This structure system enables to obtain abundant natural light which is the architectural demand of this facility. In the "Light-Thread" portion, in-plane stiffness of the wall is obtained by bridging with lattice of steel flat bar within the walls thickness of 400mm.

The other is the "Semi-rigid parabolic truss" of the roof. This structure is so-called composite beam system of concrete plate and steel beam. New roof structure with architectural diversity is proposed by locating each structural element in position where their capability can be utilized. This concrete plate secures the horizontal stiffness uniting with the wall in three dimension, and treats the in-plane stress of the roof emerged by the horizontal forces. Moreover, this plate bears a part of out-plane bending stiffness of the roof. The steel beam which supports the concrete plate secures the out-plane bending stiffness of the roof, and treats the bending moment of the roof emerged by the vertical forces. Therefore, it is defined as semi-rigid structure which is the intermediate structure of composite beam and non-composite beam. Moreover, the steel beam is a parabolic truss. The structural system is imperfect truss structure system for its parabolic shape of the lower chord, however it has sufficient strength as a structure.

 

E-3

Structure outline 3

■Sizing of foundations

According to the report, the underground water level of this site is near to the ground surface.

Taking this concern into account, minimum basement is planned.

The foundation system is a pile foundation as the measure against lift when the underground water level rose to the ground surface. Economic and rational pile diameter and length is decided based on the results of standard penetration test.

 

■Structural design and reliability analysis of temporary seats to be added during the Olympic Games

Seats in the north-south upper rows of the arena are movable. Flexible structure is adopted to those seating, so that they can be utilized as seats of the arena during the Olympics and of athletic field in the main campus of CAU after the Olympics. The structural system is designed considering the transfer to outdoor. The steel structure with the precast concrete plate is applied for its demolition, transportation, and refabrication.

Seats in the east-west lower rows of the arena can be moved and stored. Flexible structure is adopted to those seating, so that they shall be utilizable as a seat if needed after the Olympics. The structural system is designed considering its storing and moving. The light steel structure is applied for its storing, transportation, and refabrication.

 

■Structural style and reconstruction method of associated and service facilities that can be rebuilt after the Olympic Games

Walls which are planned to be transferred according to the modification of intended use after the Olympics are non-earthquake resisting wall, and the partition wall will be supported by steel studs and furring strips. Bolted joints are applied to each connection in principle, so that the detail will be simple for transfer.

 

E-4

Structure outline 4

■Structural Concept

The present facility functions as the venue for the wrestling competition during the Olympics and general arenas of the university. The facility consists of the roof (RC + S) with the semi-rigid parabolic truss, the wall of thin-walled spatial structure which supports the roof, and the reinforced concrete rigid frame structure with earthquake resisting wall which supports the interior space.

 

Structural elements of the roof are the thin reinforced concrete plate which maintains the in-plane stiffness of the roof, and the steel beam which supports the plate. The combination of those elements realizes the semi-rigid structure, in which the thin reinforced concrete plate with very large in-plane stiffness resists against horizontal force such as earthquakes, and the steel beam resists the transverse bending moment. Light-thread and skylight are provided in this thin reinforced concrete plate, and introduces the natural light to the interior space.

Moreover, this plate is very important for improving the performance of sound insulation at heavy rain which is peculiar to Beijing and heat insulation of the building. The steel beams are arranged in the short span direction, and the structure is an imperfect parabolic truss in both parallel and perpendicular direction of the beam.

The structure which supports the roof is the reinforced concrete wall. This wall transfers the vertical force from the roof and horizontal force in the in-plane direction to the lower structure utilizing the very large in-plane stiffness. For the horizontal force in the out-plane direction, it resists using the in-plane stiffness of the plates (the roof and the wall) located effectively in each direction. This wall has "Light-thread" as the same in the roof, in order to realize internal space with natural light.

Reinforced concrete rigid frame structure with seismic resisting wall is applied to the rigid frame which supports the interior space considering its seismic resistance.

Earthquake resisting wall resists against earthquake of grade eight by locating them with balance.

 

These " Semi-rigid parabolic truss and Thin-walled spatial structure" are new technologies symbolizing the "High-tech Olympics", though they are realizable by utilizing the existing technology.

Furthermore, the present facility accomplished the integration of the architectural design with structure taking rationality, economical efficiency and construction feasibility into consideration, and will become the legacy to posterity as the symbol of "New Beijing" and "Great Olympics".

 

 

F. Special features of Semi-rigid parabolic truss

 

■Composition of Semi-rigid parabolic truss

1.thin reinforced concrete plate

2.parabolic truss

 

■Treatment of vertical force

Vertical force such as self load acting on the roof is transferred to the foundation through the structure of imperfect truss system and building perimeter wall.

 

■Treatment of horizontal force

Horizontal force such as seismic force acting on the roof is transferred to the foundation through the thin reinforced concrete plate and the building perimeter wall.

 

■Upward wind pressure on the roof surface

The safety factor will increase against upward wind pressure by giving sufficient self-load to the roof surface, in addition to the high bending rigidity in the thickness direction.

Present method has been proven to have the following wind force coefficient from the previous wind tunnel test, however it will be reconfirmed by carrying out the wind tunnel test to the present facility.

 

■The Advantages of Semi-rigid parabolic truss

・ The structure is economical, because the thin reinforced concrete plate resists against horizontal force acting on the roof, and no additional steel structural element is required.

・ The cubic space is obtained rationally by accommodating the form of the seat area, and the structural form also has advantages from the natural lighting and acoustic points of view.

・ The rational building integrating architecture and structure is realized, by giving flexibility to the arrangement of "Light thread"and skylights which provides natural light to interior space.

・ It is easy to secure performance of heat insulation and sound insulation compared with conventional light-weight roof (for instance, folded steel plate).

 

 

G. Special features of of Thin-walled spatial structure

 

■ Composition of Thin-walled spatial structure

In this new structure, reinforced concrete wall structure is combined with "Light-Thread" and with itself in three dimension.

 

■Treatment of vertical force

Vertical force such as self load acting on the roof is transferred to the foundation as the in-plate force.

 

■Treatment of horizontal force

Horizontal force such as seismic force acting on the roof is transferred to the foundation as the in-plate force.

 

■The Advantages of Thin-walled spatial structure

・ The thin wall is realized, by uniting with the roof in three dimension.

・ The rational building integrating architecture and structure is realized, by giving flexibility to the arrangement of "Light thread" and skylights which provides natural light to interior space.

・ It is easy to secure performance of heat insulation and sound insulation compared with conventional light-weight roof (for instance, folded steel plate).​