17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020
Paper N° C C002277
Registration Code: S-A01704

Sliding-Rocking Combined Actions at Base Foundation Influencing Global andLocal Deformations of Upper Wood Structure
T. Nagae(1), S. Uwadan(2), K. Takaya(3), C. Yenidogan(4) (5), S. Yamada(6), H. Kashiwa(7), K. Hayashi(8),T. Takahashi(9), T. Inoue(10)(1) Associate Professor, Nagoya University, nagae@nagoya-u.jp(2) Graduate Student, Nagoya University(3) Undergraduate Student, Nagoya University(4) JSPS Fellow, Nagoya University, cem.yenidogan@gmail.com(5) Assistant Professor, Bahçeşehir University, cem.yenidogan@eng.bau.edu.tr(6) Associate, NIKKEN SEKKEI LTD, shohei.yamada@nikken.jp(7) Senior Researcher, NILIM, kashiwa-h92ta@mlit.go.jp(8) Assistant Professor, Toyohashi University of Technology, hayashi@ace.tut.ac.jp(9) Senior Researcher, NIED, takehiro@bosai.go.jp(10) Deputy Director, NIED, dinoue@bosai.go.jp

Abstract
A three-story wood test building was prepared to assess the sliding-rocking combined action at the foundation as well as
its influence to the response deformations of the upper wood structure. The test building adopted a generic construction
method of the Japanese Grade-3 index building. A reinforced concrete foundation was constructed on a 1.5 m-high soil
layer. Then, the upper wood structure was fully constructed anchored to the foundation. The entire test system was setup
on the large shaking table facility at E-Defense, and a series of tests were conducted using Maximum-ConsideredEarthquake motions. Regarding the foundation performance, the initial friction and cyclic friction strength capacities
between the foundation and soil were quantitatively evaluated. Rocking at the foundation was assessed with theoretical
uplifting capacities. Energy dissipation was calculated to the different deformation mechanism, and the distribution in theentire test system was shown.
Keywords: Shaking table test, Wood house, Soil-structure interaction, Functionality, Base isolation

1. Introduction
The 1995 Kobe earthquake and 2011 Tohoku earthquake caused catastrophic consequences to buildings andinfrastructures. Solutions are the most important social issue in such earthquake-prone regions. Primary visions
to enhance the resilience capacity of human communities have induced a shift of the relevant assessment
methodology from approaches towards individual components to more comprehensive approaches towards
entire building systems. This test program regarding full-scale wood dwellings produced real foundation-soil
interactions. Figure 1 shows the test setup of a pair of three-story test buildings. B-building on the soil box
adopted the special experimental function. [1] [2]Fig. 1

Setup of the test building (B-building), and the foundation constructed on 1.5 m-high soil

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

2. Test System
The test system included the 1.5m-high soil in a rigid soil box of the size of 1.7 m (H) x 7.0 m (W) x 13.0 m(L). Silica sand was used for the soil layer. The soil base was divided into five layers with a height of 0.25 m.
Each layer was inspected by the SWS test after compacting. Figure 2 shows the construction process. The
locations of the SWS tests are also shown in the figure. Table 1 shows the results the SWS test. The inspectedvalues reached three times the guideline requirement of 30 kN/m2. The reinforced concrete foundation was
designed assuming the equivalent ground condition. Then, the foundation was constructed according to a
generic construction procedure, which started from a leveling concrete set and a broken stone foundation set.
Figure 3 shows the plan and partial cross section of the foundation. Regarding the upper wood structure, aShear-Wall structure known as the Two-by-Four construction was adopted. Figure 4 shows the plan of the firstfloor and framing elevation. The three-story building has a height of 9,879 mm and plan of 4,550 mm (X:Longitudinal direction) x 10,010 mm (Y: Span-direction).

Foundation

(4)

(3)

1.280

(5)

(1)

Fig. 2

Construction of soil and locations of SWS test

Table 1 Soil evaluations by SWS test (allowable stress values for sustained loading)
SWS test for soil

(1)

(2)

(3)

(4)

(5)

Average(kN/m2)

85.2

89.4

82.8

81.0

86.4

85.0

Fig. 3 Plan and cross section of reinforced concrete foundation

2(2)

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

Fig. 4 Plan of the first floor and framing elevation
The design of the Grade-3 index building was applied. The stress margin to the requirement was
minimized. That is, the design stress level to the design base shear coefficient of 0.3 was close to the allowablestress level. The total weight was 790.9 kN. This consisted of the roof level (79.9 kN), third floor level (146.9kN), second floor level (149.7 kN), first floor level (71.0 kN), and foundation (343.4 kN). Table 2 shows theseismic force used in the design.
Table 3 shows the physical boundary conditions of the test systems in each sequential test of Phase 1,
Phase 2 and Phase 3. In the first Phase 1, the foundation was set on soil. In the second Phase 2, twenty castiron plates were inserted between the foundation slab and soil to change the friction resistance. Note that castiron is known as a steady lubricant. [3] Figure 5 shows the locations of the cast iron plates in the foundation
plan. The installation procedure is also shown in the figure; the soil was excavated from the exterior parts ofthe foundation, and after installing the cast iron plates, the same original soil was returned and compacted. The
remained parts of leveling concrete were removed in this process. In the third Phase 3, the foundation slab was
firmly fixed to the rigid soil box by stiff steel beams and high-tension bolts.
Figure 6 shows the setup process of the test system to the E-Defense table. The sequential process ofcarrying, lifting and placing on the E-Defense table was carefully and slowly proceeded. Conditions of thefoundation on soil were stable in the rigid soil box. After placing the test system on the table, the bottom flangeof the soil box was firmly fixed to the table with a number of prestressing steel bars.
Table 2 Seismic force used in the allowable stress design
Total weightwi (kN)

Ai

Shear force coefficient
Ci

Seismic forceeQi (kN)

3rd story

79.91

1.60

0.480

38.32

2nd story

226.83

1.21

0.363

82.31

1st story

376.50

1.00

0.300

112.953

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

Table 3

Testing program and boundary conditions of foundation

Phase / Test datePhase 1January 31, 2019
February 1, 2019

Phase 2February 7, 2019
Phase 3February 12, 2019

Steel frame
Concrete wall
Test soil layer
Leveling concrete
Cast iron plate20(11) JMA-Kobe 100%

2

3

4

5

6

8

18

9
16

15

14

13

12

Condition of foundation

Foundation slab set on soil

Cast iron plates inserted between
foundation slab and soil
Firmly fixed foundation

7

19

17

Fig. 51

Input motion(1) JMA-Kobe 25%(2) JMA-Kobe 50%(3) JR-Takatori 25%(4) JR-Takatori 50%(5) JMA-Kobe 100%(6) JR-Takatori 100%(7) JMA-Kobe 25%(8) JMA-Kobe 50%(9) JMA-Kobe 100%
(10) JR-Takatori 100%1110

Base slab
Cast iron plate
Supporter
Jack

Locations of twenty cast-iron plates in the foundation plan and the installation procedure

Fig. 6 Setup process of the test system to the E-Defense table

3. Test Results
The acceleration spectra were evaluated by sensors placed on the foundation slab and shaking table. Figure 7
shows the comparisons of acceleration spectra evaluated in Phase 1. The spectra of the foundation slab and theshaking table were identical in the X and Y-directions in JMA-Kobe 50%. The results of JMA-Kobe 100%
were different from JMA-Kobe 50%. The spectrum amplitude of the foundation slab was smaller than that of
the shaking table in the period range of 0.3 sec -1.0 sec in each direction. The same trends were observed in4

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

JR-Takatori 100%. The spectrum amplitudes of foundation were lager than that of that shaking table at theperiod range of 0 – 0.8 sec in the Z-direction. The horizontal acceleration spectrum was influenced by slidingof the foundation, and the vertical acceleration spectrum was influenced by rocking of the foundation, as statedbelow.
Table
振動台
基礎
Foundation
slab

振動台
Table
基礎
Foundation
slab

Table
振動台
基礎
Foundationslab

X-direction
X方向

Y-direction
Y方向

Z-direction
Z方向(1) JMA-Kobe 50%
振動台
Table
基礎
Foundation
slab

振動台
Table
基礎
Foundation
slab

振動台
Table
基礎
Foundationslab

X-direction
X方向

Y-direction
Y方向

Z-direction
Z方向(2) JMA-Kobe 100%

振動台
Table
基礎
Foundation
slab

振動台
Table
基礎
Foundationslab

X-direction
X方向

振動台
Table
基礎
Foundationslab

Y-direction
Y方向

Z-direction
Z方向(3) JR-Takatori 100%

Fig. 7 Acceleration spectra evaluated by sensors placed on the foundation slab and shaking table
(1X)

(2X)
(3Y)

(2Y)

X-direction

Y-direction(Unit: mm)(1Y)

Fig. 8 Sliding displacement orbit of foundation during JMA-Kobe 100% and JR-Taktori 100%
Regarding the tests of Phase 1, Figure 8 depicts the orbits of two-directional sliding displacement at thefoundation. Figure 9 shows the time histories of the sliding displacement in the sequential tests. The maximum
lateral sliding displacement reached 240 mm in the X-direction and 100 mm in the Y-direction during JMAKobe 100%. The maximum lateral sliding displacement reached 300 mm in the X-direction during JR-Takatori
100%. The foundation moved around on the soil without touching the soil box.

5

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

X-direction (Sequential test data)(1)JMA-Kobe100%
JMA-Kobe
100%
JMA
神戸波100%Y-direction (Sequential test data)(2)
JR-Takatori
100%
JR-Takatori
100%JR
鷹取波 100%(1) JMA-Kobe
JMA-Kobe100%
JMA 神戸波 100%
100%

(2)
JR-Takatori
100%
JR-TakatoriJR鷹取波 100%
100%

Fig. 9 Sliding displacement time history in the sequential tests of Phase 1

Before test

After test

(1) VP drain pipe line system

Before test

After test(2) Polyethylene gas pipe system

Fig. 10 Embedded pipelines dragged by sliding foundation when subjected to JMA-Kobe 100%
Figure 10 shows the embedded pipelines were dragged by the sliding foundation when subjected to JMA-Kobe
100% in Phase 1. Brittle VP drainpipes were fractured resulting in a significant loss of the functionality. On
the other hand, polyethylene gas pipe system showed high deformability, as shown in Fig. 10 (2), butmaintained the inside gas pressures even after the test of JR-Takatori 100%.

3.1 Hysteretic Behaviors of Foundation and Upper Structure / Phase 1
Figure 11 shows the hysteretic behaviors of the foundation and upper structure observed in the tests of
Phase 1. Figure 11 (1) shows the relationship of the shear force coefficient and sliding displacement of thefoundation, and Fig.11 (2) shows the relationship of the story shear force coefficient and story drift angle atthe first story. The figure legend, D1/X1 stands for the record of X1 axis shown in Fig. 8. The axes of X2, Y1,
Y2 and Y3 are also shown in Fig. 8. In JMA-Kobe 50%, the maximum sliding displacement of the foundation
was only 3.5 mm. The maximum shear force coefficient of the foundation was 0.63 in the X-direction and 0.45
in the Y-direction. The maximum story drift angle was 0.003 rad in the X-direction and 0.007 rad in the Ydirection. In JMA-Kobe 100%, the maximum sliding displacement reached 240 mm in the X-direction, while
the maximum shear force coefficient of the foundation was 0.91 in the X-direction. The maximum story drift

6

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

angle was 0.008 rad in the X-direction and 0.015 rad in the Y-direction. In JR-Takatori 100%, the maximum
shear force coefficient of the foundation was smaller than that of JMA-Kobe 100%, and was 0.68 in the Xdirection. The maximum story drift angles were close values of JMA-Kobe 100%, and 0.008 rad in the Xdirection and 0.015 rad in the Y-direction.
Regarding the response of the foundation, the highest value of shear force coefficient of 0.91 was shownat the start moment of the first sliding in JMA-Kobe 100%. The shear force coefficient decreased and kept thevalues at around 0.6 during JR-Takatori 100%. This indicates that shear failure occurred in the soil beneaththe foundation with significant first sliding and the condition of the soil changed to a relatively stable condition.
Regarding the responses of the upper structure, the maximum story shear force coefficient was 0.8 in JMAKobe 50% and 1.2 in JMA-Kobe 100%. The stiffness remained even in JMA-Kobe 100%. That is, the shear
force response of the first story became 1.5 times when the input motion was increased by two times. This
indicates that the sliding of the foundation provided the upper limit of the shear force in the upper structure.

3.2 Hysteretic Behaviors of Foundation and Upper Structure / Phase 2
Figure 12 shows the hysteretic behaviors of the foundation and upper structure in Phase 2. Figure12 (1)shows the relationship of the shear force coefficient and sliding displacement beneath the foundation, andFig.12 (2) shows the relationship of the story shear force coefficient and story drift angle at the first story.
During JMA-Kobe 50%, the foundation started sliding, and the maximum sliding displacement of thefoundation reached 100 mm. The maximum shear force coefficient of foundation was 0.48 in the X-direction

JMA-Kobe
50%

JMA-Kobe

X-direction

Y-direction

X-direction

Y-direction

X-direction

Y-direction

Y-direction

100%
X-direction

JR-Takatori
100%(1) Foundation

Fig. 11(2) First story

Foundation- soil system: (1) Shear force coefficient and sliding displacement at the foundation,(2) Story shear force coefficient and story drift angle at the first story

7

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

JMA-Kobe
50%

Y-direction

X-direction

X-direction

Y-direction

X-direction

Y-direction

X-direction

Y-direction

JMA-Kobe
100%

JR-Takatori
100%(1) Foundation

Fig. 12(2) First story

Foundation -cast iron plate-soil system: (1) Shear force coefficient and sliding displacement at thefoundation, (2) Story shear force coefficient and story drift angle at the first story

and 0.36 in the Y-direction. The maximum story drift angle was 0.003 rad in the X-direction and 0.008 rad in
the Y-direction. When subjected to JMA-Kobe 100%, the maximum shear force coefficient of foundation was
0.65 in the X-direction. The maximum sliding displacement exceeded 300 mm in the X-direction. The
maximum story drift angle was 0.008 rad in the X-direction and 0.014 rad in the Y-direction. During JRTakatori 100%, the maximum shear force coefficient of the foundation was smaller than that of JMA-Kobe
100%, and was 0.64 in the X-direction. The maximum sliding displacement exceeded 400 mm. The maximum
story drift angles were 0.007 rad in the X-direction and 0.015 rad in the Y-direction. Regarding the responseof the foundation, the shear force coefficient gradually increased from 0.3 to 0.6 as the sliding displacement
increased. The presence of cast iron plates was effective in JMA-Kobe 50%. Regarding the responses of theupper structure, the maximum story shear force coefficient became lower in Phase 2 than in Phase 1 whensubjected to JMA-Kobe 50%.

3.3 Overturning Moment and Rocking Rotation of Foundation
Figure 13 shows the relationship between the overturning moment and rocking rotation angle at the foundationslab when the test building was subjected to JMA-Kobe 50% and JMA-Kobe 100%. The two horizontal dottedlines show the decompression moment and ultimate moment reflecting the total weight (See the illustration
shown in the upper part of Fig.13). During JMA-Kobe 50%, the overturning moment exceeded thedecompression moment in both the X and Y-directions. The relationship maintained the first gradient, and therotation angle slightly exceeded 0.002 rad in the Y-direction. During JMA-Kobe 100%, the relationship8

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

showed different shapes in the X and Y-directions; with the overturning moment slightly exceeding theultimate moment, the rocking rotation reached 0.015 rad. The ceiling of the overturning moment due to upliftof the foundation slab provided the upper limit of overturning moment to the wall base level.

𝑇𝑜𝑡𝑎𝑙 𝑤𝑒𝑖𝑔ℎ𝑡: Σ𝑊

𝑊 ＋𝑊 ＋𝑊 ＋𝑊 ＋𝑊
791 𝑘𝑁𝑎 𝑊
Σ𝑀
𝐸𝑐𝑐𝑒𝑛𝑡𝑟𝑖𝑐 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒: 𝑒Σ𝑊𝑎 𝑊𝑴𝒐𝒎𝒆𝒏𝒕 𝒄𝒂𝒑𝒂𝒄𝒊𝒕𝒚 𝒄𝒐𝒓𝒓𝒆𝒔𝒑𝒐𝒏𝒅𝒊𝒏𝒈 𝒕𝒐 𝒓𝒐𝒄𝒌𝒊𝒏𝒈
𝐷𝑒𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑖𝑜𝑛 𝑀𝑜𝑚𝑒𝑛𝑡

𝑀 _

Σ𝑊・𝑟
621 kN・𝑚

𝑀 _Σ𝑊・𝑟1341 kN・𝑚

𝑊
𝐻
𝑊

𝑎 𝑊

𝐻

𝑎 𝑊

𝑊

𝑎 𝑊
𝑎 𝑊

𝐻

𝑊

𝐻
𝐷

𝑊

𝑟

𝑟

𝐿/6

Σ𝑀
Σ𝑊

𝑈𝑙𝑡𝑖𝑚𝑎𝑡𝑒 𝑀𝑜𝑚𝑒𝑛𝑡

𝑀 _
𝑀 _

Σ𝑊・𝐿/21863 kN・𝑚
Σ𝑊・𝐿/24022 kN・𝑚

𝐿/2

X

𝐿

direction

Centroid 𝐿 /2𝐿 /2
Y

direction𝐿

JMA-Kobe 50%

X-direction

Y-direction

X-direction

Y-direction

JMA-Kobe 100%

Fig. 13

Overturning moment and rocking rotation angle at foundation (Phase 1)

9

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

4. Energy Dissipation in Comparison to the Fixed Foundation CaseIn the condition of the fixed foundation, the shaking table input was fully applied to the foundation in Phase 3.
As a result, significant fractures of the wall bases occurred between the sills and shear wall panels.[2] Figure
14 shows the relationships between the base shear force coefficient and drift angle when subjected to JMAKobe 100% in Phase 3. The maximum drift angle reached 0.08 rad in the X-direction, and exceeded 0.1 rad in
the Y-direction. The shear force decreased to less than 20 % of the maximum shear force. The relationships of
the Phase 1 tests are added in the figure. The sliding and uplifting of the foundation provided the upper limitof seismic force to the upper structure in Phase 1. Therefore, the upper structure avoided the ultimate failure,
and the maximum drift angles were limited to 0.018 rad.
Figure 15 shows the total energy dissipation including the results of other test cases. [1][2] The entire test
program was planned with another test building adopting the Post-and-Beam structure (A-building). In the firststage, Phase 1, A-building accommodated a generic base isolation system, and in the following Phase 2, its
foundation was firmly fixed. In each test case shown in the lower part of Fig.15, the total energy dissipation

Fig. 14 Comparisons of responses of upper structure in Phase 3 and in Phase1

Wall and column bases
Base-isolation layer(Phase 1 test of A-building)Wall and column bases
Zone beneath foundation(a) Overturning moment / Rotation

Wall and column bases
Zone beneath foundation

3rd story
2nd story
1st story(c) Story shear force /Story shear deformation(b) Shear force / Sliding displacement

A-building

Base-isolation

Fig. 15

B-building

A-building

Base-isolation

Fixed-foundation Shear Wall Structure

B-building

Fixed-foundation Shear Wall Structure

Fixed-foundation Post-and-Beam Structure

Fixed-foundation Post-and-Beam Structure(1) X-direction(2) Y-direction

Distribution of energy dissipation in the entire structural system (JMA-Kobe 50% and 100%)10

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

was calculated in reference to the hysteretic behavior of each local deformation mode and the corresponding
seismic forces depicted in the upper part of Fig.15. The evaluations of total energy dissipation are equivalent
in JMA-Kobe 50% and JMA-Kobe 100%, respectively. Regarding JMA-Kobe 100 %, the energy dissipationof B-building mostly occurred at the foundation in Phase 1, but mostly in the upper structure in Phase 3. The
total values of energy dissipation are equivalent. The same trends are also derived from the other test cases ofA-building, which adopted the condition of the first base isolation system and the second fixed foundation.
That is, when the upper structure has a strength capacity sufficient to cause the foundation to slide or rock, thetotal system exhibits a similar energy dissipation mechanism to the base-isolation system.

5. Conclusions
A three-story wood test building was prepared to assess the sliding-rocking combined action at foundation as
well as its influence to the response deformations of the upper wood structure. The test building adopted ageneric construction method of the Japanese Grade-3 index building. A reinforced concrete flat foundation
was constructed on a 1.5 m-high soil layer. Then, the upper structure was constructed to represent an entire
building structure. Regarding the foundation sliding, shear strength and cyclic friction strength were
quantitatively evaluated. Uplifting due to the foundation rocking was assessed with the theoretical evaluations.
The upper structure avoided critical failure due to wall base fractures because such inelastic behavior at thefoundation provided the upper limit of seismic force to the upper structure. Energy dissipation distributions
including the other synchronizing tests indicated that the energy input of ground motion was mostly shared by
the foundation exhibiting the inelastic deformation. Such energy dissipating mechanism was similar to a
generic base isolation system. The effect of damage mitigation was significant in the Maximum-Considered
Earthquake level.

Appendix 1: Overturning Moment and Resisting Moment
Total energy dissipation due to rocking of the foundation can be calculated in reference to the hysteretic loopsof the over-turning moment and rocking rotation in each X-Y direction. On the other hand, in order to calculate
the energy dissipation due to compressive force and deformation in soil, the compressive zone was definedassuming the total compressive force is equal to the total weight (Appendix-fig. 1). The vertical displacement
data of the foundation was used to define the compressive zone. Appendix-fig. 2 shows the examples ofcalculated vertical displacement distribution of the foundation slab. Appendix-fig. 3 shows the assumed
compressive hysteresis of soil. The energy dissipation values assessed by two methods indicate that the totalenergy dissipation due to rocking of the foundation is equivalent to the energy dissipation of compressed soil.
Over-turning moment

Resisting moment

Inertia force

Resultant force
Subgrade reaction

Center of compression resultant

Comparison of over-turning momentand resisting moment
Compression
area

Distance between compression
resultant and center of gravity：Acceleration vector：Height vector：Overturning moment vector

Center of gravity
Foundation base

Appendix-fig. 1 Overturning moment of the upper structure and resisting moment of the foundation

11

17th World Conference on Earthquake Engineering, 17WCEE
Sendai, Japan - September 13th to 18th 2020

Appendix-fig.2 Compressive displacement distribution converted the vertical displacement records
Compression force σ・ΔA

Energy absorption of resisting moment
2

1

8

5

3

4

6

σy ・ΔA

7

Compression deformation δ

Appendix- fig 3 Compressive hysteresis assumption in each grid of compressive zone of soil

Work[kNm]

Ratio to total energy aborption (%)
13%
12%

8%
31%

18% 14%

19%

JMA-Kobe 25%

JMA-Kobe 50%

JR-Takatori 25%

8%

JR-Takatori 50%

Appendix- Fig. 4 Comparison of calculated energy dissipation

5. Acknowledgements
This work is supported by the Tokyo Metropolitan Resilience Project of the National Research Institute for
Earth Science and Disaster Resilience (NIED). Collaboration on earthquake engineering research using EDefense and NHERI facilities is proceeding continuously. Construction of the test buildings was managed by
ICHIJO Co., Ltd. Test-relevant affairs were administrated by the Graduate School of Environmental Studies,
Nagoya University and E-Defense, NIED.

6. References[1] T. Nagae, S. Uwadan, C. Yenidogan, S. Yamada, H. Kashiwa, K. Hayashi, T. Takahashi, T. Inoue (2020): The 2019full-scale shake table test program of wood dwellings. 17th World Conference on Earthquake Engineering, 17WCEE,Paper No. C002274.
[2] T. Takahashi, T. Nagae, S. Uwadan, C. Yenidogan, S. Yamada, H. Kashiwa, K. Hayashi, T. Inoue (2020): Stiffness,
ultimate strength capacity and cyclic loading deterioration characteristics of two different wood-structure dwellings
following the current Japanese practice. 17th World Conference on Earthquake Engineering, 17WCEE, Paper No. C002285.
[3] R. Enokida, T. Nagae, M. Ikenaga, M. Inami, M. Nakashima, (2013): Application of graphite lubrication for columnbase in free standing steel structure, J. Struct. Constr. Eng., AIJ, Vol. 78 No. 685, 435-444 (in Japanese)12