towards evolving a bridge management system for jkr

7/29/2019 Towards evolving a bridge management system for JKR

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TOWARDS EVOLVING A BRTDGE I'TANAGEMENTSYSTEM FOR JKR

By: I r . Tham Kum Weng+Ir . Khoo Chin Leong . ;

I r . Ng See King *


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TOWARDS EVOLVING A BRIDGE I.I.ANAGEMENTSYSTEU FOR JKR

By: Ir. Tham Kum Weng+Ir. Khoo Chin Leong'a

I r . Ng See King *

ABSTRACT:Although there are well over 2300 bridge structuresscattered over the major Federal roads network inPeninsu lar Malays ia , to proper or systemat ic br idgemanagement system exists to-date to coordinate thedesign, construction and maintenance activi t ies relatedto bi idges. Recent work carried out under the MalaysianNat i_ona1 Axle Load Study ( l -986-1988) has discoveredserious d.amages to many bridges. The najori ty of thebridges were damaged by environmental factors rather thanby vehicle loadings. Although the damages could not beentirety el iminated., they cou1d, however, be rninimisedwi th proper care in deta i l ing, a t tent ion to factorsaffecting durabil i ty during design stage and properquali ty control during construction. Final ly, a propermaintenance system which stresses on regular inspectionwould arrest distress at an early stage and thus preventwid.espread damage and consequent costly repairs-This paper highl ights the development towards evolvinga systematic bridge manag:ement systern for JKR Malaysia(tha Public Works Department of Malaysia) . This is i-nIine with the real isation of the vital need to paygreater attention to the preservation and consolidationof bridge structures buil t during pre-independence daysand over the past five Malaysian Development Plans-

Roads Branch, Ft{D MalaysiaIlighway PLanning Unit, PWDMalaysia


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INTRODUCTIONBackgrouudIn Malaysia, i t is the conventional role ofBridge Unit of JKR (Public Works Department) tocarry out design works and offer technicalservices with respect to problerns arising fromconstruction of bridges or poor performance ofexisting bridges as reported fron time to time.Traditionally, brid.ge problems are dealt with ona case-by-case basis in an ad-hoc manner.Decisions are being made by individual bridgeeng'ineers based on their heuristic knowledge. Assuch, they are subjective and not uniform.The National Axle Load Study in i t3 bridgeinspection exercise has made observations on thestructural integrity of some Malaysian bridges.A large number of bridges need imlrediateattention of the Bridge Unit, due to structuralinadequacy or functional obsolescence either asa result of deterioration or increase vehicularload of present day traffic. What is moreworrying'is the observation that most Malaysianbridges are suffering from premature fai lurebrought about by the various factors to behighl ighted later in this paper.This calls fo r an overall bridge managementsysten (BMS) that wil l provide a comprehensivesystem from the point of design, construction andrnaintenance. A microconputer-based infornationsystem shall be created to provide decisionsupports to the Bridge Managers in the BridgeUn i t .The need to inventorise the nationrs bridges wasfirst realised when KAMSAX A/C, Denrnark inassocia t ion wi th SSP, K.L. was engaged to preparea bridge inventory in 1972-74. This inventory waspartial ly updated around t979. The data containedin the Kamsax fnventory is somewhat lirnited.There is, for exarnple, no data to support ananalysis to assess the load carrying capacity ofa bridge structure.An attenpt to initiate a systematic bridgeinspection and sirength assessment was made UVBridge Unit in L984. Bridge inspection forns weredesigned to gather field bridge data sb that somesirnple analyses could be perfomed to rate the


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.bridges in 'terms of their load-carryingcapac i t i es t1 l .In Apr i l L987, the-senior Ass is tant Dj - rector ofBridge Unit in his working paper enti t ledt'Establ ishing a bridge inspection and maintenancesystern for JKRrr has again highl ighted the needto systematical ly inspect and maintain thenat ionrs br idges. The paper e laborated on aproposed organisational set-up of an tinspectionand maintenancer section within the Bridge Unit.The National AxIe Load Study (Phase I) startedin Decernber 1985 and completed in october 1-987has helped to create a bridge inventory of some956 bridges on a few main Federal routes 12). Thesecond phase of the study, which comprisesbasical ly bridge inspection on major Federalroutes not covered under the Phase I Study isunderway at.the present moment. The inventoryprepared by the study, though helpful i- n manyways, does not in itself consti tute acomprehensive bridge manaqement system. The vastamount of data collected during the study howeverwould be useful if a bridge management system j-sto be developed.In June L987, Kamsax International A/S and theDanish Road Directorate had presented to the JKRa project proposal for a bridge naintenancemanagement system. The proposal was not acceptedowing to the high cost involved. Besides, a fewof the proposed items of work had already beenundertaken in the National AxIe Load Study.At the same tine, the Japanese InternationalCooperation Agency (JICA) has also proposed toconduct a rMaster Plan Studyr on the naintenanceand rehabil i tation of bridges in Malaysia.To-date the rnatter is sti l l being discussed bythe Malaysian and Japanese Governments. TheMaster Plan Study shall be programmed and carriedout in three phases, v iz ; l ) Phase f : rev iewingexisting data; 2) Phase II: systernatic inspectionand evaluation of existing bridges and preparinga bridge inspeetion manual and 3) Phase fII:budgeting and feasibi l i ty study on packaging ofrehabil i tation or repair works within theparticular chosen route. The emphasis of thestudy is on the identi f ication of deterioratedor deficient bridges and .the preparation ofdocurnents to repair or rehabilitate them.


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The Trigger: The National Axle Load StudyIn the course of bridge-by-bridge inspection, theNational Axle Load Study team had discovered alarge number of bridges suffering from severedisLress, t1pical1y in the form of cracking/spall ing in reinforced concrete structures; andcorrosion in the case of steel structures.Although vehicular overloading beyond the legallirnits is common p1ace, damage due to such factoris extremely rare.The rnajofi ty of the damages afe' caused byenvironmental factors. Carbonation, chlorideingress, corros ion, su lphate at tack etc- , cou ldal l be attr ibuted to external agents- In theIocal scene, such factors are exacerbated by alack of attention to detai ls affecting durabil i tysuch as type of cenent and cover reguirernents,poor quali t l control and supervision at the site.In spite of this, i t is fett that many of thestructures could have been prevented fromreaching the leve1 of distress encountered hada systen of regular inspection and rehabil i tationbeen available. The National AxIe Load Study, incoming up with a complete inventory of al l bridgestructures in the network under study, has se tthe frarnework fo r the establishrnent of an overallsystem to manage the nationrs existing stock ofbr idges:

TEE APPROACE fN SYSTEI.i DE.IrELOPUENTSysten requirenentsA JKR BMS System Development Tearn was fornred tostudy and dJvelop a bridge management system forJKR.In developing the bridge management system, thefol lowing points have been taken intoconsiderat ion: -i . a well-defined boundary of the systemii . a systerns approach in systern developmenti i i . to ensure user acceptabil i tYiv. system to be simple but completev. possible future expansion of the systemTo define the system boundary, the objectivesthe system nust f irst be establ ished. Thisd i scussed i n i t em 4 .1 .3 .

o fi s


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A systems approach is imperative in the systernsdevelopment process in oider to avoid the 'rhydraeffectr common among progranmers who wriLeprogranmes before {frei lroperly plan ands t ruc tu re t he a lgo i i t t rmsef fectr :er iminat ing one defect lead ing tJ tnecreat ion of many nore) .A systgqs a_pproach is more than just beingsystematic. A seven-process system developmentl i fe cycte (based on tech-niques .'=-"d-'- i .,Management rnformation systen) is recommendedi3 l . I t cons i s ts o f :i- Conduct init ial studyii . Analyse current systirni i i . propose systen solutioniv. Detai l chosen d.esignv. . Design.new physical systernvi. Construct nLw-systemvii . Instal l and non-itor systern

2.2 System DevelopneutThe seven-process methodology as discussed above!3= been transrated into tne forrowing threephases : -

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This phase incrudes literature research onsystems used by other countries especially theU.s.; col lect ion of systen data; st i ra ies on thd:yt.:T!. practice in the Bridge Unir;rqenErrLcation of systen objectives etc.

This phase involves prototlping the man-machinesysten based on the fogicif iodel created inPhase f. The activi t ies to be perforned by man.I " _being laid down in work procedures orstandard manuals/guides. The operalions that canl":t be performed- by a computer are transformed.into computer prograrmes.

This phase is the implementationsystem. It shall include thehardware and software needed bythe training of staff.

of the proposedacguisit ion ofthe system and

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Strateg'yThe users of the management system are basical lyengineers from the niiage Unit. To afford useiaiceptabi l i ty, the engineers and technicalassistants of the Bridge Unit and HighwayPlanning Unit are directly involved in thedevelopment of the systen. This is in l ine withthe JKR|s decision against acquiring anrro f f - the-shel f t t system.The strategy now is to cone up with a simple butcomplete system with a provision for refinementin future when the need arises. To be conpletemeans that the systen must have the barestrninirnum components of a bridge management systen( for e.9r a pr ior i t isa t ion model, a pred ic t ionmodel and a data bank). For a complete system tobe simple, only few parameters in a model needsto be considered. Additional parameters may beincluded later when the system is expanded.The system should now ain only at bridges alongthe federal routes. Future extension to stateroads must be considered.The need and possibi l i ty of integrating theproposed bridge managenenC systern to i,rre existing. pavement management system, BS(M) to effect anoverall road rnanagement system has also been aconsideration in tne systJrn development.The BMS Systern Development Team shall detail thesystem design to whatever leve1 it is capable.Private consultants may be engaged for moredetai led system design.

THE CURRENTPRACTTCEAs a f i rs t s tep to proposing a log ica l .nodeI forthe JKR BMS, the current practice of managing ourexisting bridges in the Bridge Unit is reviewedto identify weaknesses that have to be overcomein the proposed.system. It is depicted in a dataf low diagran in Fig . f .This semblance of tsystenr was only establ ishedaf ter L.4 .1-986 wi th the re-organisat ion in Publ icWorks Departrnent whereby the Bridge Unit wastransferred frorn the Design & Research Branch tothe Roads Branch. With such re-structuring theobjective and role of the Bridge Unit was


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conditions. The alternative with the nrinimumpresent cost sha11 be recommended.4 .2 .2 The p red i c t i pn Mode l .The prediction Model supports the priori t isationModer by predicting or Lrtirnating the irnpacts ofeach improvement alternati"" - in teruns of costsand extended serv ice f ives.- Besides, the Prediction Moder -i"o forecasts future needs farin advance for the purpose of proper planning andbudgeting; and tire - requisi l ion for specialfundingr. fn order to ao a conceptual costestimate, th: quantit ies ina unit

"6=Jor-in"proposed work must f irst be d.etermined. tn"estimated .quantity of work for one or moreimprovemelt option! sha11 be made by the BridgeEngineer .during a detai l .a-i"=p"ction. standardunit costs are establ ished i 'n- a database ofbridge costs based on bid rin" i tern pricessubnitted by contractor= o. , p."-nions contracts.

4 .2 .3 The Da ta BankThe Data Bank is the core of the overall bridgemanaqement system. It , store= ,r="f.rf bridge dataneeded to. support the priori t iEtion u"d"r.

-anathe predic t ion Model . r i - - ; i ; " s tores and.manipulates data to proviae . basic Uridgeinforrnation to the users - The bridge d.ata arestored in three formats; ,,.r"fy ir , "orpoter databases , f i l e s and n l c ro f i lms . Anicrocornputer-based database nanagenent systemdBASE rv is used for the data bases. rig. 5 showsthe data erernents to be storea- in these databases. Fi1es are used to feep records of old.correspondence and - design-cornipt"tio"- .*".a=.As-built structural ara'wi-ngs---ua" stored i_nmicrof i l rns.

5 . 0 RELATED DE.\rELOPUEIITSWhile the JKR BMS when fu11y developed andsuccessful lv lrnplenented wiff evintual lyel irninate n6st of 'the ;;-u;.=ses. in the currentpractice in mainta.ining "xi=ti1g-- uri-ag"=, i tcannot be over-enphasis;a tne irp6.i"-""" of theBridge unit lookiig into two other rnajor areas:j ,O.i9_n1 engineering i.e. planning and design,.and construction of bridges. Tha fol lowiigssummarise the status of frogr"== in these twoareas : -


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INVENITORY DATABASE1.2.3.4.5.6.7.8.9.10.11.12.13.t4 .15.16.17.18.19.20.2L.22.23.24.25.26.27.28.29.30.31.32.

JL) .34.35.36.37.38.39.

Route No. :Structure No.Name of StructureName of RiverName of DistrictStateYear of ConstructionCorrespondenceFile RefTlpe of MaterialType of SystemCrossingDegree of SkewnessMaximum Span LengthNo. Of SpansTotal Length of StructuresCarriageway WidthOverall WidthLoad-Carrying CapacityDiscounted CapacityDeck TlpeAbutment TypePier TypeFoundation TypeVertical ClearanceHorizontal ClearanceEnvironment ConditionADTVoof Heavy VehiclesModified ADTNavigable or NotAny Electrical ServicesAny Telecom SevicesAny Lighting ServicesAny Water MainsHighest Flood ClearanceFoundation Cond. RatingAbutment Cond. RatingPier Cond. RatingBearing Cond. Rating

Girder Cond. RatingDeck Cond. RatingSurfacing Cond. RatingJoint Cond. RatingParapet Cond. RatingApproach Slab Cond. RatingSlope Cond. RatingWeighted Cond. RatingProposed Maintenance CostEquivalent AgeRemarkDate of Entry

40.4t.42.43.M.45.46.47.48.49.50.51.HISTORY DATABASE

Route No.Structure No.Project No.Nature of WorkYear of ImprovementDesignerContractorTotal CostDesign File Ref.

COST DATABASE1.2.3.4.5.6.7.8.9.10.

ProjectNo.ContractSumTendererStateDate of TenderJob No.Job DescriptionQuatity of WorkAmountUnit Cost

Fig. 5 Data Elements of Databases


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Planning and Design of New BridgesBased on the field' inspections of the existingbridges :-.t t""",tJ y"tt=- the planning. and designof new brid'ges hav-e been toitittoouify upgradedespecia l ly in- areas of deta i l ings ' cho ice ofmaterials ""a =il" l t i"tt iott= ' As a result

of acontinuous programme r.n recent' years thefo l lowings have -b""" ach ieved:-Br idoe Desiqn GuideA Bridge Design Guide.vias publi '*hed in l-9.85' Thisbook containilt J"=ig" lirocedures'

guides andworked exarnples on siinple bridge -design wascirculated' to aII JKR stale and dii t l i"-t-:f f ices 'This served to create a greater awareness ofbridge engi-neering arnong u iia"r spectrum of JKRengineers ""J- n&p"a to cultivate a

healthyinterest among the engLneers besides providingbasic grr ides.

A new specification for bridge construction wasdrafted.. Part of the new specification wasincorporated into the Standard Roadspecifications r"""Ln"a in July L989 while thebalance of in" -Jp"citications witl be fullyimplementea ny-19t0' The specification .serves toimprove the guality controi auring constructionand arso "'i;- "t irnpr-ving tne . materialspec i f i ca t i .on -s- . i . ' ' tn " r i ^en to fcu r ren t f ind ings;;:-^;;t;;i; i- deteriorition' rhe standardspecif ications tiir be iropllmented' country-wide'

A new bridge loading specif ication wa-s beingf ormulated ir, ' "tJ"t t 'o ichieve standardisationfor all future bridges so as to :1t-"^1'fot theirnplementatj-on of the Long Term Axle Load (LTAL)policy. FulL ;.;r";+*it l of the poricv couldnot be ettected-unti l al l the existing stock ofbriages are ful '1Y uPgraded'Bridoe Desiqn CriteriaA draft of Bridge Design Criteria incorporatingthe latest f indi'ngs ana -dePartrnental requirementswas draf ted i" t i ' tu r icat ion in 1990 ' Th is

wi I Icomplement th-J-B;id;" Design Guide and enable a

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uniform criteria in design of bridges by JKR andprivate consultants doin! JxR proj-ects ]Standard Br idqe BeansA new series of standard prestressed concretebeams wil l be developed i; l ine with the newbr idge loading speci f icat ion. This wi l l rep lacethe existing series of standard beams developedover the years s i nce 1970rs .Deta i l i nqAttention to detai l ings and structuralinteraction of the various Lridge components wirlbe continuously upgraded.Construct ion of New Br idgesIn order to ensure the proper t rans la t ion ofdesign in to the construct ion and complet ion ofnew bridgs, the Bridge unit has comrnenlced akinga more active rolg in providing technical supportto the construction and supervision teams.Frequent interaction between design engineers andfierd engineers has afforded the p-rop"i "x""utionf neer.bridges in recent years-. S-ite problemsy"l".guick1y settled and wea-knesses in ae-sign and.detai l ings could be read.i ly overcome and r61ayed.to the design engineers fof further improvement.

CONCLUSTONfhis paper outl ines the basic process involved1n tle development of a Bridge lt-anagement systernfor JKR. rt deals in some aeptrr witf, the various'problems and aspects to be considered in theelaborat ion of maintenance pol icy and someimportant factors necessary for th; successfulimplementat ion of an overa l l systen.Arthough this management system is stir l in i tsinfancy stage, ' i t is hoped -tnat as more and morernronnation and data becorne available in thecourse oi i ts . inprementa i ion, any def ic ienc iesor weaknesses in the systern can be identified andrecti f ied. At the current rate of progress, itis envisaged that the BMS wilr be i"-"p"rationby L992.


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7 . O ACKNOwT,EDGEI{'ENTThe autlrors rvish to express their thanks to otLrermembers of tlr" JfcR gMS System Development

Teamfor theit "o"p"tt i ion and good efforts'They are: I r ' Chew Swee- Hock ' Pi l ' Rohani A 'Razak, Po- ;;";--Lot r"ra.'

-- zin ' Tr_' shamsudinrsmair, Er. ' f,; ' -;;;"

-ij a==n"a' En' Stramranl lohamed l{ashim, Eil ' I ' Iohd Hisham Mohd Yassin' Ert'Zainudin Jasmani, Err ' Leovr Choon Heng' Err' Abd'Lati f Moklrtar, PD' Salmaft-- efa' Wahab' ciksabar iah e" .h i i and' En' She Tian Hock 'Thanks are also due -uo Pn' Siti Hafsalr Kusni fortyp ing and. n;;n*"g -tl?

manuscript ' ' and En 'l , lohd. Suha:-ni nif i" ior his ad'vice on dBASE Iv'The authors acknowled'ge with thanks the kindper:nission of tne oirettor General of JKR' Tansri Dato' r;. Talha r ' l tona' Haslrim f or thisDaper to be puri isned and presented'

REFERENCE1. Mansf ie ld ' , Rober t f S " and-Ng ' S ' K ' ' r rThe Needfor Bridge Inspection and' Strength Assessmentrr 'JIG' Jourial , (Dec ' 1984 ) '2 . Economic Planning Uni t ' Government of Malays ia 'D ra f tF i na lnepo r t ' o ; - ; " i " Load 'S tud ' ybynende lPa lmer&Tr i t t o t ' - i t J ' i nassoc i l t i onw i thMinccnsur t sdn. eha. jo in t ry wi th Kementer ianKe r j a raya (1987 ) '

Kozar, Kenneth, A' , Hulnani-zPdlr-fgr-mati-gltSvstensenatvsis ana o!s-i 'Jl@ng- Fvstems

torPeoo t -e , Mc Cr f f i f r co . , N 'Y ' (1988)

4. Brj-dge Design Guid'e of Brid'ge lJnit ' Design andResearch Branch o?-p"ffic Works Department'

Ma laYs ia (Nov ' 1985 ) '

towards evolving a bridge management system for jkr

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