Improvement of bridge's ability and repair&reinforcement method Improvement of ability method of simple and continuous span P.S.C and the Preflex composite bridge by Up-Down Method

repair&reinforcement method  1. simple bridge  when it need to change slab of existing bridge, equal upper step. only addition  breaking concrete. if existing bridge slab do not change, the step is the next.       removing concrete of center girder( preserving existing reinforced rod)      equipping the temporary support & up girder           concrete slab concrete at center and  cure the concrete surface.      remove the temporary support and falling girder ( introducing compressive  at the lower part girder) falling

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Improvement of bridge's ability and repair&reinforcement method Improvement of ability method of simple and continuous span P.S.C and the Preflex composite bridge by Up-Down Method

2. continuous bridge    improvement ability method's step of continuous 2 span P.S.C &     Preflex composite bridge by part removing slab method    production step  construction step order chart  STEP1 part removing slab concrete & connecting    STEP2  concreting partly slab concrete   STEP3 up inner support    STEP4  entirety removing slab concrete   STEP5 down inner support    STEP6  completion

 

Improvement of bridge's ability and repair&reinforcement method Improvement of ability method of simple and continuous span P.S.C and the Preflex composite bridge by Up-Down Method

improvement ability method's step of continuous 2 span P.S.C &    Preflex composite bridge by entirety removing slab method   production step construction step  order chart  STEP1 part removing slab concrete & connecting   STEP2  concreting partly slab concrete   STEP3 up inner support   STEP4  entirety removing slab concrete   STEP5  down inner support   STEP6  completion

 

Improvement of bridge's ability and repair&reinforcement method Improvement of ability method of simple and continuous span P.S.C and the Preflex composite bridge by Up-Down Method

effect improvement ability of existing bridge     1. simple bridge      the subject bridge : the location Imshhil-Gun ,Chollabuk-Do, simple support       PSC Beam bridge, Sasun overhead bridge          length of girder 17.4m, length of bridge 18m, wide of bridge 9.25m       It has been completed at 1973 , the second grade   effect : The basis durability increases form DB-20 to DB-29   <a panoramic view>  <cross view>

 

Improvement of bridge's ability and repair&reinforcement method Improvement of ability method of simple and continuous span P.S.C and the Preflex composite bridge by Up-Down Method

Sasun overhead bridge of The rising quantity, the falling quantity and     occurring stress at final step   classification ¡¡ inner span outside span  the rising force ¡¡ 11.97 ton  13.68 ton  the falling force ¡¡  -17.79 ton  -19.51 ton the rising displacement ¡¡  0.63 cm  0.72 cm the falling displacement  ¡¡  -0.42 cm  -0.46 cm  final stress ¡¡ the lower beam ¡¡  -2.24 Kg/cm2 (compressive)  10.69 Kg/cm2 (tension)  the upper slab ¡¡  -50.66 Kg/cm2 (compressive)  -56.25 Kg/cm2 (compressive)   classification ¡¡ before improvement of ability   after improvement of ability(basic design) the comparison  Sasun overhead bridge (L=18.0m)   design load ¡¡ DB_18 DB-24   The basis durability ¡¡  DB-20  DB-29 45% increase

 

Improvement of bridge's ability and repair&reinforcement method Improvement of ability method of simple and continuous span P.S.C and the Preflex composite bridge by Up-Down Method

2. continuous bridge ( basic design )     the subject bridge : the location Ulsan city, simple support of 20m span ,       continuous 2 span of 20m span & continuous 3 span of 30m span, PSC       Beam bridge.          length of girder 550m       the second grade      effect : The basis durability increases form DB-18 to DB-37   yaemdong direction                                        myoungchondong direction  myoungchon large bridge's general view (a) center of span (b) end point of span (a) center of span (b) end point of span   20m PSC Beam's general view               30mPSC Beam's general view ¡¡

 

Improvement of bridge's ability and repair&reinforcement method Improvement of ability method of simple and continuous span P.S.C and the Preflex composite bridge by Up-Down Method

myoungchon large bridge's of The rising quantity, the falling quantity      and occurring stress at final step     classification  PSC Beam span L=30m ¡¡  continuous 2 span continuous 3 span   the rising force  24.59 ton 14.28 ton   the falling force  -17.64 ton  -8.26 ton  the rising displacement  6.22 cm  3.61 cm the falling displacement   -3.86 cm 1.81 cm  final stress  the section of positive moment  the lower beam 12.31 Kg/cm2 (tension) 10.69 Kg/cm2 (tension)  the upper beam  -86.57 Kg/cm2 (compressive)  -88.50 Kg/cm2 (compressive)  the upper slab  -14.79 Kg/cm2 (compressive) -16.33 Kg/cm2 (compressive) the section of negative moment   the lower beam  -131.4 Kg/cm2 (compressive)  -114.71 Kg/cm2 (compressive)   the upper beam  16.46 Kg/cm2 (tension)  -5.42 Kg/cm2 (compressive) the upper slab  12.75 Kg/cm2 (tension)  0.47 Kg/cm2 (tension)    classification ¡¡ before improvement of ability after improvement of ability(basic design) the comparison    simple support(L=20m) design load  DB-18  DB-24 ¡¡ The basis durability DB-18 DB-26 30% increase   continuous 2 span (L=20m) design load    DB-18  DB-24 ¡¡ The basis durability DB-20 DB-33 65% increase   continuous 3 span (L=30m) design load    DB-18  DB-24 ¡¡ The basis durability DB-20 DB-37 85% increase

 

Improvement of bridge's ability and repair&reinforcement method Improvement of ability method of simple and continuous span P.S.C and the Preflex composite bridge by Up-Down Method

the method connecting at the section inside support       it is point that bending tension moment at upper girder and bending       compression moment at upper girder for continuing P.S.C and the Preflex       Beam.    1. method A (P.S.C Beam)    For bending tension stress at continuing support using chemical anchor at PSC    Beam's upper, it  correspond effectively, and connecting with girder is planed    for compressive stress at lower girder. Fig. a Fig. a (the method connecting P.S.C Beam)     2. method B (Preflex Beam)     bending tension stress at connecting at the section support at upper girder     and compressive stress at lower girder is corresponded by effectively     connecting Beam and Beam. Fig. b (the method connecting Preflex Beam)

 

Improvement of bridge's ability and repair&reinforcement method improvement of ability method using crack-fasten of P.S.C Beam acting bending crack

improvement of bridge's ability and repair&reinforcement method * <improvement of ability method using crack-fasten of P.S.C Beam   acting bending crack> ( patent number 10-1999-007572 ,  patent number 10-1999-045825 ,  patent number 10-1999-04582 ) 1. outline   Presently existing bridge have many problem. so it require repair & reinforcement   existing method of repair & reinforcement have variety problem.   this method of construction overcome the problem of other existing method of   repair & reinforcement : it is made improvement of unreliable injecting by loading   pre-load at structure occurring bending crack and pure into injection. then it is   made improvement of repair & reinforcement by getting rid of pre-load. the   reason is that bending crack concrete occur compressive stress. so this   method of repair & reinforcement is fitting and trusting.

 

Improvement of bridge's ability and repair&reinforcement method improvement of ability method using crack-fasten of P.S.C Beam acting bending crack

construction step and stress view     ¡¡

 

Improvement of bridge's ability and repair&reinforcement method Iimprovement of ability method using crack-fasten of P.S.C Beam acting bending crack

¡¡   Fig. 2 force of construction by stages Fig. 3 effect of inducing stress ¡¡

 

Improvement of bridge's ability and repair&reinforcement method improvement of ability method using crack-fasten of P.S.C Beam acting bending crack

experiment view                      (a) loading pre-load                (b) injecting epoxy resins                                               and curing the concrete surface Fig. 4 loading pre-load and injecting epoxy resins          Fig. 5 being completed hardening of injecting   table 1 loading-deflection relationship   load deflection before repair&reinforcement deflection after repair&reinforcement   measuring date of experiment  analysis of finite element  measuring date of experiment  analysis of finite element 3  5.78 6.89  5.06 5.62 6  14.16  13.79  9.26  11.24 9  20.47  20.68  13.88  16.87 12  25.73  27.58  23.94  22.48 16  36.4  36.77  26.6  29.97 20  45.50  45.96  37.5  34.46 24  -  -  45.27  44.95 28  -  -  52.43  52.44 32  -  -  60.50  59.94 34  -  -  65.95  63.68 37  -  -  72.00  69.3   this date is showed : comparing measuring date of experiment with analysis of   finite element

 

Improvement of bridge's ability and repair&reinforcement method improvement of ability method using crack-fasten of P.S.C Beam acting bending crack

comparing a method of construction    we apply this method to simple PSC composition beam of reinforcing as    External Prestressing method. then  we compare stress condition    * the subject bridge : moonle overpass    * the time of completed : 1979    * type of upper structure :single span PSC composit beam    * external state : deterioration of slab and girder, crack occur at PSC beam,       bending crack  length 20~80cm, wide 0.1~0.3m. result of crack's deep, crack       exceed reinforce rod's cover.       so need structural reinforcement.    *  profile factor's rate : 15%   Fig. 6 moonle overpass's cross section

 

Improvement of bridge's ability and repair&reinforcement method improvement of ability method using crack-fasten of P.S.C Beam acting bending crack

table 2 comparing stress in service load    classification ¡¡ upper section Kgf/cm2 low section Kgf/cm2   the comparison stress before damage  DB-18 -91.23  12.07   exceeding allowance stress DB-24  -97.88  32.92 stress after damage DB-18  -96.29  39.89  DB-24 -102.94  60.79 External Prestressing DB-18  -77.29  -12.60 satisfactory design load  DB-24 -83.93 8.3 Preloading DB-18 -91.16  -4.20 DB-24 -97.81 16.70  resulting of comparing this method to External Prestressing method by inducing  at simple PSC beam,  the lower part of PSC beam inducing stress quality is  smaller 8.4kgf/cm2 then External Prestressing method, but this method secure  durability except additional repair&reinforcement method.

 

Improvement of bridge's ability and repair&reinforcement method Repair method at inner support of continuity Steel Box Girder using injection concrete

Repair method at inner support of continuity Steel Box Girder using injection concrete   1. outline     This method is repair method : after clearing rot, lowering stiffness is repair.   * rotting of inner support in Box wall     water store at inner support because  of camber. so it occur rotting of inner     support in Box wall  Fig. 1 flow of water leakage by camber  * Repair method using injection concrete    if rotting of inner support in Box wall is removed like Fig. 2 , thickness of   flange&web is drop and stiffness is reduction.      Fig. 2 Box inner wall occurring rot

 

Improvement of bridge's ability and repair&reinforcement method Repair method at inner support of continuity Steel Box Girder using injection concrete

¡¡     Fig. 3 after removing corrosion     Fig.4 Being reinforced at section negative moment by injecting concrete.

 

Improvement of bridge's ability and repair&reinforcement method improvement of continuity bridge's ability method using weight

1. outline   Presently existing continuity bridge was constructed without preparing negative   moment at inner support. so slab concrete was cracked and stiffness and   durability was decline. finally, this crack is made dark action as structure and   dark effect as using & durability.   improvement of continuity bridge's ability method using weight is a method   introducing compressive stress at negative moment inner support. so crack is   prevented and this method have an advantage at deflection & shock.

 

Improvement of bridge's ability and repair&reinforcement method improvement of continuity bridge's ability method using weight

2. improvement of continuity bridge's ability method using weight      step 1 removing slab at section negative moment                  step 2 loading after repairing across beam   load is decided by tension reinforced rod quantity and moment . this moment is   that across beam's ability resistant.       step 3 removing after concreting slab at section negative moment   through step 1~step 3 , induce compressive stress at section negative   moment's slab. so it is     resisted negative moment acting live load. this method is applied at plate   continuous bridge and steel box continuous bridge's repair method and over 3   span.

 

Improvement of bridge's ability and repair&reinforcement method improvement of continuity bridge's ability method using weight

3. structure computation's example    structure computation perform for ability application this method , actually    constructed 2 span   continuous preflex bridge, using finite element analysis    modeling.    this modeling is 2 span continuous bridge , span length 45m, this bridge is    location Inchon city,    public overpass. Fig. 1 is cross section view of preflex bridge. Fig. 2 is cross    section view of 1 preflex beam. Fig. 3 is cross section view of across beam of    section positive moment and section negative moment. and table 1, table 2 is    section's character using  finite element analysis.   Fig. 1 cross section view of preflex bridge  table 1 section's character of preflex beam beam ¡¡ beam+slab beam A 2524 1522 Ix 8678835.2 4581683.8 Iy 4634171 570109.1 J 1885243.8 277118.8 Fig. 2 cross section view of preflex beam

 

Improvement of bridge's ability and repair&reinforcement method improvement of continuity bridge's ability method using weight

table 2 section's character of across beam and slab ¡¡ across beam slab across beam+slab across beam of connecting section across beam of connecting section-slab A 370.6 323.5 694.1 2491.6 2168.1 Ix 340477.9 16850 1087095.2 6110930.9 3897394.0 Ix 27794.1 326225.5 354019.6 2927906.1 2601680.7 J 111176.5 67402.0 178578.5 5880763.4 5813361.0 ¡¡ Fig. 3 across beam and slab (1) detail construction step   ¨ç adhering strut     a-1. cross section of beam     Fig. 4 crossing section with beam , adhering strut at lower across beam

 

Improvement of bridge's ability and repair&reinforcement method improvement of continuity bridge's ability method using weight

a-2. cross section view of connecting section  Fig. 5 adhering strut at lower across beam    b-1. a ground plan ( view at down ) Fig. 6 adhering strut's shape at down  ¨è injecting concrete     a-1. cross section of beam Fig. 7 injecting crossing section with beam

 

Improvement of bridge's ability and repair&reinforcement method improvement of continuity bridge's ability method using weight

a-2. cross section view of connecting section     Fig. 8 injecting concrete  of connecting section    ¨é removing slab       a-1. cross section of beam Fig. 9 removing upper flange at crossing section with beam

 

Improvement of bridge's ability and repair&reinforcement method improvement of continuity bridge's ability method using weight

a-2. cross section view of connecting section Fig. 10 removing upper flange at connecting section    ¨ê injecting epoxy at section across beam crack       a-1. cross section of beam Fig. 11 injecting epoxy at across beam upper cracking section of crossing section  a-2. cross section view of connecting section Fig. 12 injecting epoxy at across beam upper cracking section of connecting section

 

Improvement of bridge's ability and repair&reinforcement method improvement of continuity bridge's ability method using weight

¨ë loading     a) bending moment of ability removing slab's across beam        * the out side of across beam        M=204.5 tm      * inner across beam

 

Improvement of bridge's ability and repair&reinforcement method Iimprovement of continuity bridge's ability method using weight

b) loading weight result finite element analysis, negative moment 330ton occur when 100ton load at G beam. so weight is 63.3ton for occurring negative moment 204.5ton. so weight is 60ton.   c) loading weight *step 1  Fig. 13 cross section and a ground plan of loading step 1's weight *step 3  Fig. 14 cross section and a ground plan of loading step 3's weight

 

Improvement of bridge's ability and repair&reinforcement method improvement of continuity bridge's ability method using weight

¨ì  concreting slab and release   Fig. 15 cross section and a ground plan of concreting slab and release   (2) final stress    table 4 final stress of weigh and live load    ¡¡ the out side of across beam the inner side of across beam the point of load bending moment by live load ¡¡ 412.8tm 412.8 tm ¡¡ upper stress by live load ¡¡ 28.57 Kg/cm2 (tension) 42.85 Kg/cm2 (tension) ¡¡ bending moment by weigh ¡¡ 235.32 tm 248.82  tm 147 tm upper stress by weigh ¡¡ 17.53 Kg/cm2 (compession) 25.8 Kg/cm2 (compression) 21.9 Kg/cm2 (tension)the (section lower casing) final upper stress ¡¡ 11.04 Kg/cm2 (tension) 17.05 Kg/cm2 (tension) ¡¡

 

Improvement of bridge's ability and repair&reinforcement method repair&reinforcement method of pier's coping

1. outline   this method repair and reinforce crack acting at pier's coping supporting the   upper part bridge.    Fig. 1 cracking shape 2. existing method of construction.

 

Improvement of bridge's ability and repair&reinforcement method repair&reinforcement method of pier's coping

Fig. 2 is existing method of construction. the method have problem of maintaining existing method using frequently have many problem.

 

Improvement of bridge's ability and repair&reinforcement method repair&reinforcement method of pier's coping

3. construction method   this method is that: after  it load cracking load at coping of acting crack, extend crack. then using epoxy resins, fill crack, remove load. finishing. Fig. 3 after cracking load, fill injection filling injection 3. effect   this method improve 150~200% of practical coping durability as introducing compressive at total coping.