30 4 JOURNAL OF VIBRATION AND SHOCK Vol. 30 No. 4 2011 1 2 3 1. 361005 2. 200235 3. 361008 P315. 5 U442. 5 + A Pseudo static test for pre-cast segmental bridge columns with dry joints GAO Jing 1 GE Ji-ping 2 LIN Tie-liang 3 1. Dept. of Civil Engineering Xiamen University Xiamen 361005 China 2. School of Urban Construction and Safety Engineering Shanghai Institute of Technology Shanghai 200235 China 3. Highway Bridge & Tunnel Maintainence Center in Xiamen Xiamen 361008 China Abstract The similarities and differences of a seismic performance between a pre - cast segmental bridge column and a cast-in-place bridge column were investigated with a test project including five kinds of concrete bridge columns. Prestressed tendon construction methods arrangement and bonded state of prestressed tendons and additional energydissipating bar were selected as test variables. Through the pseudo static test of the five kinds of concrete bridge columns the development rules of failure mode failure area load-displacement hysteretic loops opening of segmental joints residual displacement distribution of curvature energy dissipation ability and viscous damping ratio were gained. The experimental results showed that the segmental column experiences opening-closing between segmental interfaces under cyclic loading the change of curvature focuse on the area of the segmental interfaces the segmental bridge column has no plastic hinge mechanism at the bottom of the column as commonly seen in conventional reinforced concrete bridge columns the addition of energy dissipating bars crossing the joint can delay the gap opening increase the strength and the hysteretic energy dissipation of the column it certainly helps anti-earthquake the residual displacement of the segmental bridge column with bonded or unbonded prestressed tendons is less and the segmental bridge column with energydissipating bars has bigger residual displacement it is close to that of a cast-in-place bridge column. Key words pre-cast segment dry joints pseudo static test energy-dissipating bar aseismic performance 1-2 3 50508032 YYY09007 2009-11 - 23 1979 2010-01 - 26 1997 Mander 4 2002 Hewes Priestley 5
212 2011 30 6 2006 Hewes Billington 7 2004 1. 1 2005 8 9 1 2. 5 2006 Palermo Pampanin 10 1 1 240 mm 180 mm 1240 mm 1 800 mm 240 mm 7. 5 C40 10 mm HRB335 6 mm R235 250 mm 1 50 mm 80 mm 10 mm 1 50 mm 80 500 mm Φ j 12. 7 65 kn 11. 2% 10% 1 Fig. 1 The dimension of specimens and section reinforcement details
4 213 1. 2 0. 5 / 3 ± 2 mm 3 mm 5 mm 7 mm 10 mm 0. 01 Hz ± 5 mm ± 10 mm ± 20 mm ± 30 mm ± 40 mm ± 50 mm ± 60 mm ± 70 mm ± 80 mm ± 90 mm ± 95mm 3 80% 1 Tab. 1 Serial Numbers and main characters of all specimens RC UBPC UBPC-S UBPC-SD BPC-S 15 mm 0. 02 Hz 20 mm 25 mm 30 mm 5 mm 1 /4 - - - 2 2. 1 3 Fig. 3 Damage state of precast segmental bridge column 2 2. 2 4 RC UBPC UBPC-SD UBPC-S BPC-S 2 2. 2. 1 Fig. 2 Damage state of cast-in-place bridge column 4 b c
214 2011 30 UBPC-S UBPC UB- UBPC-S UBPC-S PC-S UBPC 60% UBPC-S UBPC-S UB- PC UBPC 4 - Fig. 4 Load-displacement hysteretic loops BPC-S RC 2 Tab. 2 The key points of load and displacement /kn /kn /mm /kn /mm 2. 2. 2 RC 20. 4 15 23. 0 19. 6 63. 5 UBPC - S UBPC 26. 1 15 29. 3 24. 9 64. 5 UBPC - S 13. 1 15 16. 3 13. 9 57. 5 UBPC - SD UBPC - SD 15. 1 15 21. 4 18. 2 61. 7 UBPC - S BPC - S 20. 1 15 22. 8 19. 4 71. 2 UBPC - SD UBPC 2. 4 2. 3 5-6 2
4 215 5 6 7 Fig. 5 Envelope curve of loaddisplacement hysteretic loops Fig. 6 Relationship of displacement and dissipating energy Fig. 7 Residual displacement vs. loading displacement 2. 5 X 2. 6 8 RC UBPC 1 UBPC - SD 7 RC UBPC 25 mm 5 mm UBPC - S UBPC - SD BPC - S 25 mm UBPC - S BPC - S 95 mm 15 mm 8 Fig. 8 Distribution of curvature in the plastic hinge area
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