From "technical code design" to "Material speaks design"

Norihide Imagawa Surgical Architect / CEO of TIS & PARTNERS. Co., Ltd. / Emeritus Professor of Tokyo Denki University

The Second MTC International Conference on Wood Architecture 9 November 2017

IASS WG12+18 “Timber and Environment” - September 26-30, Tokyo, Japan

1. Overview a. Introduction

2500 Projects achieved….. ● In 25 Countries ● In diverse environmental conditions ● with various materials

Material

Skeleton

= Energy volume??

Ensuring that the designed structure is safe and secure by:

1. verifying the acceptable performance of the undiscovered quality and capability of the materials and the skeleton used

2. examining the design with respect to external forces, such as gravity, earthquake, typhoon, heavy snowfall and tsunami, etc.

1. Overview b. Function of structural design recognition

Material &

Skeleton

Space &

Skeleton

Load Resistant System

OPEN

CLOSE

SLENDER

MASSIVE

1. Overview c. Figure of space and skeletal recognition

※ This red point is introduced later.

1. Overview c. Figure of space and skeletal recognition

2. The energy Theory of material and skeleton a. Background

The theory of material and skeletal energy is formulated by categorizing, analyzing and summarizing the outcomes of the completed 2500 designs and the integration value of material energy, using the theory of structure design and recognition.

1 joule of energy is equal to the force used to move a specific object 1 meter in the same direction as the force by adding an acceleration magnitude of 1m/s2

E[kN/m2] = Energy per m2

E[kN/m3] = Energy per m3 kN・m = J (unit of material energy per 1m3 )

1J = 1 kg･m･m/s2 = 1 kg･m2/s2

Function of the energy of material:

How each material works in the designed structural space?

b. The energy theory 2. The energy Theory of material and skeleton

Timber and Structural Design Timber is an organic material and is highly variable in quality compared to concrete and steel, but since it is an anisotropic material, useful life depends on usage. Therefore timber is second only to stone in structural design affecting the longevity of the structure.

<Recognizing Structural Design of Timber> 1. Use fiber direction as axial force member

2. Plan as a compression member to make a simple joint

3. Timber is a low stress intensity junction tensile member

4. Only to be used as a compression member when partnering with hybrid frames

5. Assemble in increasing bending stress increments

6. Reduce number of joints as much as possible

7. Lumber and round timber member should be 6m or less (best within 4m)

8. Laminated timber increases structural performance of long members

9. Reduce bending at the joint member

10. Avoid multiple acute member junctions

11. To avoid the burden of the same stress in hybrid members, use Yasehosori phenomenon

12. Each hybrid member should bear a single stress

13. Using low bending stiffness to omit bending

14. How thinned wood is used?

15. Reuse of the same joint

Hakone Open-Air Museum Net Forest

■ Wooden Masonry Dome ・Wooden masonry dome has been assembled using Rotegrity joints that do not use any hardware. Semi-rigid joints were used for integrity to counter the rotation of the joints. Use cast iron for the junction of net and fulcrum required a joint that has a smooth shape.

組積造

Cast iron fulcrum joint

Masonry 木 Wood/Timber

□ Construction Site Hakone-machi, Kanagawa □ Building Type playground equipment □ Design Noriko Horiuchi MacAdam □ Builder Net Noriko Horiuchi MacAdam Tent Taiyokogyo □ Structure nylon net □ Scale 1-story above ground Maximum height: 12.0m Building area: 528.5㎡

Azekura Mountain Retreat 組積造

■ Use mountain-shaped hybrid structure with rebar (25φ) and timber (Douglas fir) on the roof. ■ Use the pre-stress on rebar and building from its own weight as the frictional resistance force. ■ Retension (of the rebar on top) every year due to shrinkage of the materials.

Masonry 木 Wood/Timber

□ Construction site Azumi County, Nagano Prefecture □ Building type Pension □ Design Tsutomo Ishii + TIME Planning □ Structure timber and rebar □ Scale 2 floor above ground Building area: 367.5㎡ Total floor area: 450.0㎡

Ohara Nanafukuten Temple 筋交構造

■ The structural design of this plan was designed using a new design for V-shaped columns, not in the Japanese style, for the transmembrane structure. ■ For the basic form of the timber Rahmen frame, by using V-shaped pillars, the bending resistance was converted to axial force resistance.

V-shaped pillar detail

Brace木 Wood/Timber

Frame elevation

Exterior

V-shaped columns

□ Construction site Isumi, Chiba □ Building type temple □ Design Architect Cube □ Structure Timber □ Scale 1 floor above ground

ＫＥＬKaruizawa Home

■ Realization of a 60㎡ column-free space by using lattice beams in 2m grids. ■ Bolts and epoxy were used as bonding bolts for the Douglas fir laminated double beam grid members.

Grid Beam木 Wood/Timber

□ Construction site Kitasaku-gun, Nagano, Karuizawa-machi □ Building type Dormitory □ Design Furuhashi Architects □ Structure reinforced concrete, timber □ Scale 2 floor above ground

Analysis model

Lattice beam

Minamisanriku Asahi Kindergarten ラーメン構造

■ Joining method without using hardware 1. Transmembrane structure beam-to column joints (implantation of plug and wedge with epoxy resin injection with the plug) 2. Girder joints (large plug fittings) bonding by plug + epoxy resin ■ Use of 300 year old cedar that were damaged by the Great East Japan Earthquake tsunami

Bending Frame木 Wood/Timber

Transmembrane junctions using included plug and wedge

□ Construction site Motoyoshi-gun, Miyagi Prefecture □ Building type Educational facilities □ Design Tezuka Architects □ Structure Timber □ Scale 1 floor above ground Maximum height: 3.8m Building area: 488.3㎡ Total floor area: 376.7㎡ □ Winner of 2013 Good Design Gold Award

Health Pia Shirane 折板構造

■ Condensation was resolved by employing a half dome structure to take advantage of the wood's compression form resistance. ■ 32 3-4m wooden panels were used to form an origami-like folded plate form. The wooden dome was 3m in diameter and composed of 6 radial arrangement. ■ The folded-plate dome was designed with a simple joint using a flat bar on top with round steel at the intersection.

Top junction

Cylinder junction

Cylinder radial placement

Folder Plate木 Wood/Timber

Folded-plate dome (Interior)

Cylinder

□ Construction site Yamanashi Prefecture, Minami Alps □ Building type Hot spring facilities □ Design Tomohiko Shibata □ Structure Reinforced concrete and timber □ Scale 2 floor above ground Maximum height: 12.05m Building area: 502.284㎡ Total floor area: 552.971㎡

Onomichi Shimanami Exchange Center, station front facility シェル構造

■ Timber and RC hybrid shell structure ・temporary construction of biplane RC curved surface shell of large space ・temporary curved form of timber lattice system that uses long threaded bolt for intersection joint, using the weak bending stiffness of thin wood for the cross section

Large span roof construction

Shell木 Wood/Timber

Analysis results during long-term load

□ Construction site Onomichi, Hiroshima Prefecture □ Building type Hall, housing □ Design RIA □ Structure RC, timber □ Scale 3 floor above ground Maximum height: 24.9m Building area: 6849.0㎡ Total floor area: 32042.0㎡

Reihoku Community Hall HPシェル造

■Three-dimensional Curved Surface Slender wooden members were realized by using three-dimensional curved shear walls

■Summary The Reihoku Town Hall is a timber structure constructed for a space that is 44m long and 20m wide. In order to make the continuously changing peripheral pillars slender, the roof load must be transmitted from the girders to the inner pillars by attaching the diagonal buckling prevention member that is attached to the pillar.

■Sound Insulating Timber Hall Roof Straight members that can be configured for curved surface shear walls depending on H.P. curved surfaces were used. Various standing materials that support receipt materials which do not interfere with spatial variation and bucking were used. The hall roof is a timber and RC slab hybrid dome, that controlss sound insulation and deformation.

Reihoku Hall exterior and side diagram.

HP Shell Wall 木 Wood/Timber

□ Construction Site Hitoshi Abe, Yasuaki Onada □ Building Type Community Hall □ Design Atelier Hitoshi Abe □ Structure Timber □ Scale Building area: 394㎡

Atsushi Imai Memorial Gymnasium ペンタゴントラスシステム

■ Orthotropic dome ・steel pipes were used as the upper and lower chord member for the long side of the roof frames and T-type steel and LSL materials were used for the short side. ■ Durability in heavy snow region ・The earthquake stress full-scale experiment confirmed that the structure strength takes into account snow cover of more than 5m.

Pentagon Truss System木 Wood/Timber

Steel lattice material junction and LSL

□ Construction site Odate, Akita Prefecture □ Building type Indoor stadium □ Design Shigeru Ban Architects □ Structure Timber + steel frame and RC □ Scale 1 floor underground Maximum height: 8.0m Building area: 940.6㎡ Total floor area: 980.6㎡

Imai University Hospital Child Care 曲げわっぱ構造

■ LVL was used as a compressed material to form the arch of the tunnel-shaped structure. ■ The roof was a steel folded-plate and FRP for lighting. Glass is fitted into the hole in the LVL. ■ Contruction site is a heavy-snow region so the roof was tilted at 45° and aims to reduce the load.

Bentwood木 Wood/Timber

□ Construction site Odate, Akita Prefecture □ Building type Child care □ Design Shigeru Ban Architects □ Structure timber □ Scale 1 floor above ground Maximum height: 5.9m Building area: 131.2㎡ Total floor area: 73.84㎡

Kai Eastern Materials Market 張弦梁構造

Hybrid timber and steel lattice shell

■ The sawmill is a hybrid timber and steel lattice shell structure. By using lumber thinnings for short compression members because the long compression member has a weak bending stiffness axis due to the nature of the timber, a column free space of about 1000㎡ was designed. Round steel was used as tensile resistance member and round pipe was used to bear the compressive force and tension. ■ The pre-cut plant is a hybrid timber and steel structure. A column free space of 2500㎡ was built using members within 6m. The span between columns is 25m. Shear bending is small and compression force is large in the upper chord member. Because the lower chord member only experiences tension, a hybrid tension frame was planned.

Beam String木 Wood/Timber

Pre-cut plant

Steel and timber hybrid

Construction flow

□ Construction site Yamanashi Prefecture □ Building type factory □ Design I.N.A. New Building Research Institute □ Structure timber and reinforced concrete □ Scale 1 floor above ground

Shingu Health Promotion Center, P-UP Shingu 張弦梁構造

■ For the arch, straight and curved materials made for easy lamination of the wood. ■ For the suspension, a wood-based material called a parallam that can make thick homogenous cross sections and thin, long materials was used. By taking advantage of timber by using the parallam, the design and method of making the curve without a bending process was enabled.

Wooden roof (interior)

End joints of wooden tension member

Beam String木 Wood/Timber

□ Construction site Shingu, Wakayama Prefecture □ Building type Indoor sports facilities □ Design Furuhashi Architectural Firm □ Contractor Kumagai Gumi Co., Ltd. □ Structure reinforced concrete structure (shear wall rahmen structure) wooden roof □ Scale 2 story above ground Maximum height: 12.0m Building area: 2540.6㎡ Total floor area: 2966.0㎡

Hiroike Senkyuu Akira Nakatsu Memorial 張弦梁構造

1Unit isometrics Roof frame isometrics

Isometrics

Arched beam structure

Unit manufacturing

■ Wood-based Spatial Structure I constructed a 13mx17m large space with a three-dimensional system using a suspension truss ■ Unit Construction The construction period was shortened by fabricating units at the factory and reducing fabrication in the field. ■ Ball joint using a casting A clear pin joint was made by making the junction of the upper chord member and lower chord member a ball joint using a casting.

Beam String 木 Wood/Timber

□ Construction Site Nakatsu, Oita Prefecture □ Building Type Training institute □ Design Haruhiko Onuki/Nisso Construction □ Builders Kajimadoro, Chuto (woodwork) □ Structure Timber □ Scale 1 story above ground Maximum height: 8.7m Building area: 860.0㎡ Total floor area: 860.0㎡

Suizenji Ezuko Park Administration Building 合成梁構造

■ The structure has laminated timber pillars, and uses a construction method with concrete beams for the roof. ■ The laminated materials of the columns and beams use pin joints in places where braces are not used and the joint plate of the beam has a welded steel pipe that fits the semicircular pillar. ■ By arranging the portal of beam to column in parallel and placing the timber lattice on it, the structure is as simple and light as possible. ■ Placing diamond braces reduces the buckling length and can bear the horizontal force efficiently.

Hybrid Beam 木 Wood/Timber

Gate frame and lightweight roof Shear connector

□ Construction site Kumamoto □ Building type Office □ Design Ushida Findlay Partnership □ Structure timber □ Scale 1 floor above ground Height: 3.49m Total floor area: 266㎡

Sakuraikanseido Senseki-tei 合成梁構造

Composite beam section Composite beam

Isometrics

■ Hybrid concrete and timber beam ・Considering the vibration of the equipment on the roof, a hybrid concrete and timber beam was used for the column-free space of 6m x 8m, which has a deformation performance greater than or equal to steel beams. ・Using 2 pieces of bonded (t = 24) structural plywood for the subfloor, additional support was not required when pouring the concrete. ■ Structural design of traditional timber building ・The structural design from basic design to completion of a large-scale traditional timber building of about 700㎡ total floor space was completed in 1.5 months. ・Assuming transmembrane roof truss structure to support a large roof of about 300 ㎡, traditional "stand carrier coupling" joints were used.

Hybrid Beam木 Wood/Timber

□ Construction site Kamitakai County, Nagano Prefecture □ Building type Restaurant □ Structure timber □ Scale 2 floor above ground Maximum height: 11.6m Building area: 449.4㎡ Total floor area: 666.2㎡

Exchange Center of Kawakami-mura Forestry Research Center ハイブリッド屋根構造

■ Bending pin intersection joint Generally in timber structures, a pin joint is used and the frame is used to resist the bending stress on the joint. ■ Hybrid roof frames Using hybrid roof frame, bear tensile force with timber and compressive force with RC. The principal frame structure according to columns and beams of LVL, has to be a structure that secures horizontal stiffness by using rebar bracing as a resistance member and binds with the lag screw bolts and tension concrete. ■ Timber tension resistance frames using bending stiffness of weak wood. Office buildings employ hybrid steel and LVL frames for the roof structure. Timber is used for the short span compression material, LVL for the long bending material, and steel for tensile bending material.

事務棟内観

柱・梁交点接合部

Hybrid Roofing System木 Wood/Timber

□ Construction site Minamisaku County, Nagano Prefecture □ Building type Exhibition facilities, office □ Design Yoshihiko Iida Architects □ Structure timber and part steel frame □ Scale 2 floor above ground Maximum height: 8.3m Building area: 677.5㎡ Total floor area: 989.3㎡ □ 1998 Architectural Institute of Japan Award

Shizuoka International Horticultural Exposition フィーレンディール・トラス構造

■ Realization of a large space using a hybrid timber and steel frame by incorporating a catenary-shaped tension rod in a timber Vierendeel frame to introduce a tension rack to the whole structure. ■ For the treatment of the Vierendeel tension rod, it was transmitted to the timber shear wall at both ends (240mm thick). ■ Realization of a large space with timber beams up to 25m using arge section of laminated timber integrated side by side in 20 walls.

Vierendeel Truss木 Wood/Timber

Hybrid Frames

Front gate

Front gate

□ Construction site Hamamatsu, Shizuoka Prefecture □ Building type Exposition facility □ Design Kurio □ Structure timber + steel frame □ Scale 1 floor above ground Total floor area: 690㎡

Utukushima Future Expo 21st Century New Building

Cross-ring joint

Art tree-structuring

ツリー構造

■ A temporary exposition facility that can be relocated by dismantling, using members less than 4m long, and is currently at Fukushima Airport Park. ■ Supported by 14 pillars called Art tree-structuring. ■ Cross-ring joint for transmitting axial force in eight directions to the diagonal pillars that support the roof. ■ Cross joint for avoiding a single point of focus for less load bearing and instead is dispersed at 4 points. Tree Cross-ring joint Art

Tree 木 Wood/Timber

Crisscross joint

Cross-ring joint

外観

□ Construction site Fukushima Sukagawa □ Building type Exhibition hall □ Design Iwamura Atelier □ Structure timber □ Scale 1 floor above ground Total floor area: 661㎡ □ Awards American Wood Design Award 2002 Special Technology Commendation Award