1. EVALUATION OF RESTORING FORCE CHARACTERISTICS OF MUD-WALLS CONSIDERING EFFECT OF WALL-HEIGHT FOR SEISMIC STRUCTURAL DESIGN Hiroyuki Nakaji, Masami Gotou, Hiro Kawahara, Yoshiyuki Suzuki

2. OBJECTIVE To propose the restoring force characteristics of mud-walls for seismic structural design of wooden houses There is not enough information or manual on the structural design of traditional timber buildings (Do we really need the rules?) To compare with the usual height of 2730 mm Two different heights of specimens with same length Wall-height influences on the restoring force characteristics? 3. CONCLUSIONS (in advance) The effect of wall-height is not significant on the restoring force characteristics of mud-walls It can be assumed on the structural design of mud-walls that the wall-heights effect is negligible The restoring force characteristics for the seismic structural design were proposed and confirmed in some mud-wall cases 4. SPECIMENS WITH DODAI High Low Length 2P=1820mm Height 5. SPECIMENS WITH ASHIGATAME 6. COLUMN CONNECTIONS h W h/2 w e s Yatoi-Hozo Shachi-Sen Yatoi-HozoShachi-Sen Nagahozo Komisen 7. NAMING OF SPECIMENS MWD-2Hn-1 Mud-Wall With Dodai/Ashigatame Wall-length is 1820 mm (2P) Number of specimen Wall-height is High/Low How many Nuki in High specimen 8. MUD-WALL SPECIMENS (2010-2012) Name Length (mm) Height (mm) Number Tested at when MWD-2 1820 2730 10 TUES* 2010 MWA-2 1820 2730 3 KIT** 2010 MWD-2H4 1820 3600 3 TUES 2012 MWD-2H3 1820 3600 1 TUES 2012 MWD-2H5 1820 3600 1 TUES 2012 MWD-2L 1820 2100 3 TUES 2012 MWA-2H4 1820 3600 3 KIT 2012 MWA-2H3 1820 3600 1 KIT 2012 MWA-2H5 1820 3600 1 KIT 2012 MWA-2L 1820 2100 3 KIT 2012 * Tottori University of Environmental Studies ** Kanazawa Institute of Technology 9. Timber Frameworks on Aug 22 2012 MWD-2H3 MWD-2H5 10. MWD-2L 11. Takekomai on Aug 27 2012 12. Arakabe + Uragaeshi on Aug 28-30 2012 13. Arakabe dried 1 month later MWD-2L 14. Nakanuri on Sep 25-27 2012 15. Nakanuri 16. MUD-WALL THICKNESS = 60 mm Nakanuri 12 mm both side Arakabe 36 mm = 18 x 2 17. SHEAR CYCLIC LOADING TESTS MWD-2H4-3 on Dec 11 2012 18. LOADING PROCEDURE - 1/10 - 3/40 - 1/20 - 1/40 0 1/40 1/20 3/40 1/10 The deformation angle was increased in stages 1/480, 1/240, 1/120, 1/90, 1/60, 1/45, 1/30, 1/20, 1/15, 1/10, and 1/7 rad 1/7 rad was only for Low specimens Each deformation was cyclically produced twice or three times Actuators stroke was controlled 19. MEASUREMENT Deformation Angle (rad) 20. SETUP OF MWD-2H4 Two 9.62kN Steel Weights + 21. DATA RECORDING (MWD CASE) 6-8 seconds interval Displacements and strains Take a photo at the same time MP4 movie file was created from thousands of photos with Movie Maker after the experiment 22. SILENT VIDEO (~3 MINUTES) 23. P-DELTA EFFECT = + tan : Restoring force (kN) P: Measured load (kN) W: Steel weight 9.62 2 (kN) g: Deformation angle (rad) -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 P P g MWD-02H4-3 24. -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 restoringforce(kN) deformation angle (rad) -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 restoringforce(kN) deformation angle (rad) -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 restoringforce(kN) deformation angle (rad) -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 restoringforce(kN) deformation angle (rad) LOAD-DEFORMATION CURVE (MWD) MWD-2H4-1 MWD-2H4-2 MWD-2H3-1 MWD-2H5-2 25. -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 restoringforce(kN) deformation angle (rad) -15 -10 -5 0 5 10 15 -0.2 -0.1 0 0.1 0.2 restoringforce(kN) deformation angle (rad) -15 -10 -5 0 5 10 15 -0.2 -0.1 0 0.1 0.2 restoringforce(kN) deformation angle (rad) -15 -10 -5 0 5 10 15 -0.2 -0.1 0 0.1 0.2 restoringforce(kN) deformation angle (rad) LOAD-DEFORMATION CURVE (MWD) MWD-2L-1 MWD-2L-2 MWD-2L-3 MWD-2H4-3 26. MWD-2H4-3, 1/90 RAD small cracks 27. MWD-2H4-3, 1/20 RAD many cracks 28. -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 Deformation Angle [rad] RestoringForce[kN] 2H3 -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 Deformation Angle [rad] RestoringForce[kN] 2H4-1 2H4-2 2H4-3 -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 Deformation Angle [rad] RestoringForce[kN] 2H5 -15 -10 -5 0 5 10 15 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 Deformation Angle [rad] RestoringForce[kN] 2L3-1 2L3-2 2L3-3 LOAD-DEFORMATION CURVE (MWA) 1/45 rad 1/30 rad 29. DAMAGE AT 1/10 RAD (MWD) MWD-2H4-1 MWD-2L-1 30. DAMAGE AT 1/10 RAD (MWA) MWA-2H4-1 MWA-2L-1 31. ENVELOPE CURVES 0 2 4 6 8 10 12 14 16 0 1/20 1/10 restoringforce(kN) deformation angle (rad) MWD-2H4-1 MWD-2H4-2 MWD-2H4-3 MWD-2H3-1 MWD-2H5-1 MWD-2L-1 MWD-2L-2 MWD-2L-3 MWD-2 Ave. MWD-2 95% Lower MWD-2 95% Upper 0 2 4 6 8 10 12 14 16 0 1/20 1/10 restoringforce(kN) deformation angle (rad) MWA-2H4-1 MWA-2H4-2 MWA-2H4-3 MWA-2H3 MWA-2H5 MWA-2L-1 MWA-2L-2 MWA-2 Ave. MWA-2 95% Lower MWA-2 95% Upper MWD-2 MWA-2 32. PROPOSAL OF RESTORING FORCE CHARACTERISTICS OF MUD-WALLS 0 20 40 60 80 100 120 0 1/20 1/10 shearstress(kN/m2) deformation angle (rad) 1P-1.5P 1.5P-2P MM H Q=2M/H Q=M/H M Mud-Wall Timber Framework Mud-Wall Plate Column joint can resist bending moment Two lines are suggested because failure mode is different 33. ASSUMPTIONS Superposition principle is applicable, that is, Mud-wall is really a mud- wall plate itself plus timber framework Wall-Length has an effect on the restoring force characteristics Timber framework resists the horizontal loading at joints of members. For example, if a column joint is made using Nagahozo (mortise- tenon) and strengthened by Komisen (cotter-pin), the joint can resist bending moment 34. NAGAHOZO + KOMISEN JOINT 0 0.25 0.5 0.75 1 1.25 1.5 0 0.025 0.05 0.075 0.1 restoringmoment(kN.m) deformation angle (rad) 35. COMPARE WITH TEST RESULTS MWD-2 (Average) MWA-2 (Average) 0 2 4 6 8 10 12 14 0 0.025 0.05 0.075 0.1 restoringforce(kN) deformation angle (rad) MWD-2* Proposal 0 5 10 15 0 0.025 0.05 0.075 0.1 restoringforce(kN) deformation angle (rad) MWA-2 Proposed 36. CONCLUSIONS The effect of wall-height is not significant on the restoring force characteristics of mud-walls It can be assumed on the structural design of mud-walls that the wall-heights effect is negligible The restoring force characteristics for the seismic structural design were proposed and confirmed in some mud-wall cases