Life cycle management -Prediction -

Transcription

1 JST Oen Seminr Soro, 2 Mrh 2 Life yle mngement -Predition - Professor, Hokkido University, Jn Hiroshi YOKOTA, PhD, PE

2 Life-Cyle Mngement system Servie eriod Usge Design Environment Servie life Future ln Mintenne ln Periodi insetion Assessment nd Predition Performne Present Time Method nd timing of tion Inut/Referene Inut/Referene Dtse Insetion Predition Intervention Inut/Referene LCM system Redue LCC nd relize rtionl mintenne 2

3 Predition of deteriortion Struturl erformne Initil Present () Assumed rule nd roess Modifition rule nd roess (2) Present sttus (3) Predition Investigtion Time 3

4 Deteriortion of onrete struture Initition Progtion Aelertion Deteriortion Degree of dete eriortion Corrosion Corrosion rk Time () Chloride ion trnsorttion Crontion of onrete (2) Corrosion of reinforement 4

5 Diffusion of hloride ion Diffusion eqution 2 C C = D 2 t Solution C d, 2 ( t ) = C erf Dt C d (t,) : Chloride ion onentrtion t time tnd deth C : Chloride ion ontent t = D: Arent oeffiient of diffusion erf: Error funtion erf 2 s ( s) = e π η 2 dη 5

6 Progress of reinforement orrosion () Corrosion urrent, I orr is quntified y olriztion resistne mesurement I orr = K / R K: Constnt deending on kind of reinforement nd environment (generlly.26 V) R : Polriztion resistne (2) Diret mesurement of r dimeter y rtil destrution Corrosion rte = (Initil dimeter Present dimeter)/time Corrosion I orr Time 6

7 Predition y stohsti mthemtil model Physil deteriortion models (Fik s diffusion model, et.) re sed on theory nd my e reise, ut ) Threshold vlue is not ler, 2) Frequent oring is not referle, nd 3) Very wide vritions er. Consequently, other rohes re widely undertken: Stohsti mthemtil model ) Survivl nlysis when dmge dt re not ville e. R(t)=(+)/(+e γ(t-) ) 2) Mrkov model when dmge dt re ville 7

8 Mrkov model Mrkov models llow nlysts to study events tht reur over time. The Mrkov roerty sttes tht the roility distriution for the system t the net ste (nd in ft t ll future stes) only deends on the urrent stte of the system, nd not dditionlly on the stte of the system t revious stes. The hnges of stteof the system re lled trnsitions, nd the roilities ssoited with vrious stte-hnges re lled trnsition roilities. 8

9 Preliminry insetion formt (emle) Prt Item Method Judgment riteri Min struture Conrete dek Unevenness of fe line Crking nd delmintion/ slling Corrosion of steel r Visul insetion inluding mesurement y tes et. Visul insetion on rks, surfe erne, et. Visul insetion on orrosion nd rust stin Unevenness of 2 mm or lrger etween djent struturl units/loks Unevenness of - 2 mm etween djent struturl units/loks Unevenness of mm or smller etween djent struturl units/loks d Nothing oserved Widely etended sllingoff of onrete over or rks of 3 mm or wider Prtilly slling off of onrete over or mny orrosion rks Some orrosion rks or rtil delmintion d Nothing oserved Broken r, diretly eosed r, or hevy rust stin Muh rust stin Prtilly etended rust stin d Nothing oserved 9

10 Mrkov model : Trnsition roility er yer Rte of deteriortion Grde of deteriortion D/d C/ B/ A/ Every memer elongs to one of the Grdes Every memer strts t Grde D/d The Grde will e forwrded with every yer The finl stge is Grde A/

11 Tendenies of nlysis Proility :. Yert: Perentge t = 2 t = 2 t = 4 t= 6 Perentge =. =. =.2 =.3 Grde of deteriortion Grde of deteriortion Atully inseted results yers 3 yers 47 yers Perentge, % I II III IV V I II III IV V I II III IV V Grde of deteriortion

12 Trnsition roility, Trnsitio on roility em sl The liner reltionshi is found etween the roility nd the rte of deteriortion grde. The roility n reresent the deteriortion rte Averge grdes of deteriortion / yer =The rte of deteriortion 2

13 Deteriortion of RC suerstruture of whrf Bem Sl 3 Wide vritions er in lok of suerstruture.

14 = t d = t d d d d d d d d Grde of deteriortion Perentge investigtion model d Grde of deteriortion Perentge

15 Predition of future rogress of deformtion Numer urrent model 5 yers time D C B A Grde of deteriortion Numer (P =.36) (P =.28) D C B A Grde of deteriortion After 5 yers, memers judged Grde A eomes 3 times s muh s those t the moment. More thn 2 times. 5

16 The rmeter ffeting the trnsition roility.25 Trnsition roility =.5e -.43 =.5e -.6 Sl Bem Clerne etween HWL nd ottom surfe of memers (m) 6

17 The rmeter ffeting the trnsition roility roility Reltive ems sls y= Annul verge temerture ( C) 7

18 Struturl erformne degrdtion sed on Mrkov model Only lile to whrf suerstruture Performn e inde % (P =.949) 5% (P =.76) 75% (P =.463) Time (yer) 8