computerized database for maintenance and management of highway bridges in vietnam

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

Computerized Database for Maintenance and Managementof Highway Bridges in Vietnam

Dinh Tuan Hai1

Abstract: The deterioration of physical and serviceable conditions of highway bridges in Vietnam increasingly have become major socialand technical concerns. Moreover, the maintenance management system applied currently is considered outdated and not satisfying theactual traffic and social demands imposed on highway bridges. This paper is an attempt to develop an advanced maintenance managementsystem �V-BMS� concurrently with a computerized database for highway bridges in Vietnam. The current status of existing bridges is firstreviewed in terms of the physical condition and the maintenance management practice in order to identify outstanding problems. Severaladvanced techniques have been, therefore, introduced into the V-BMS to manage and maintain highway bridges in the most suitablemanner. Furthermore, practical application in a direct-maintenance agency is presented as an example to demonstrate the validity of thedatabase. In order to be successful, the paper recommends fully testing the system on various actual conditions of Vietnam, so necessarymodification can be made.

DOI: 10.1061/�ASCE�1084-0702�2008�13:3�245�

CE Database subject headings: Bridges, highway; Databases; Maintenance; Vietnam.

Introduction

In Vietnam, highway bridges have been constructed through theNational Highway Network. The network was initiated in 1912through construction of 2,000 km of Highway No. 1 �TMoVN2004�. Existing bridges, together with the highway system, weretherefore contributing enormously to the development of Viet-nam. However, many bridges show significant deterioration andfail to accommodate recent traffic and social demands. It is be-cause they are under the impact of many external factors, such asthe increasing traffic volume, the aggressive environmental stres-sors, maintenance budget limitations, and natural change. On theother hand, bridge maintenance management in Vietnam that hasevolved and changed throughout several historical periods differ-entiating in ownership, philosophy, standard, etc., seems outdatedand not suitable for the current requirements �Hai 2006�. A newsystem is, therefore, urgently needed now to enable local staffhandling physical problems of highway bridges and deciding op-timal maintenance management activities.

The first objective of this paper is to identify outstanding prob-lems experienced in existing bridges in Vietnam for aspects ofquality and functionality as well as maintenance managementpractice. In the second objective, a new bridge maintenance man-agement system, including a computerized database, is developedand applied in Vietnam to eliminate these problems, or at leastpartly minimize their adverse impacts. It is intended that thebridge management system introduced by this research is useful

1Faculty of Urban Management, Hanoi Architectural Univ., Km 10Nguyen Trai Rd., Hanoi City, Vietnam. E-mail: [email protected]

Note. Discussion open until October 1, 2008. Separate discussionsmust be submitted for individual papers. To extend the closing date byone month, a written request must be filed with the ASCE ManagingEditor. The manuscript for this paper was submitted for review and pos-sible publication on February 28, 2007; approved on October 8, 2007.This paper is part of the Journal of Bridge Engineering, Vol. 13, No. 3,
May 1, 2008. ©ASCE, ISSN 1084-0702/2008/3-245–257/$25.00.
JOU

J. Bridge Eng. 2008

not only for maintaining and managing existing bridges in Viet-nam, but for those in other developing countries.

Review of Previous Work on Bridge ManagementSystem

Effective maintenance management systems and computerizeddatabases for bridges have been implemented for many countriesin the world. Chase and Gaspar �2000� mentioned the use of thePontis and the BRIDGIT at U.S. Federal highway administrationto provide comprehensive supports for determining the optimumexpenditures required while maintaining a specified level of ser-vice for population of bridges. Meanwhile, the J-BMS wasconstructed for Yamaguchi-prefecture government in Japan toevaluate bridge performance, to estimate degrees of deteriorationand remaining service life, and to generate maintenance strategiesin consideration of actual costs, budget availabilities, and effectsof maintenance �Miyamoto et al. 2000�. In Vietnam, even paper-based maintenance management is currently used; several simplebridge database systems are, however, suggested. One of them isthe BridgeMan developed by the British-Parkman consultantunder consideration, but it is limited in managing bridge-relatedinventory data only �Dac et al. 2004�. The function for evaluationand prediction of current and future physical condition and ser-viceability as well as expenditure decision and optimal mainte-nance of existing bridges are so far not yet available.

Research Methodology

The ultimate goal of this study is to develop a new bridge main-tenance management system. It enables practically applying inVietnam either to eliminate outstanding problems or to minimizetheir adverse impacts. The first step is to extensively review theavailable literature of past and present bridge maintenance man-
agement systems in the world. The data collection �e.g., personal
RNAL OF BRIDGE ENGINEERING © ASCE / MAY/JUNE 2008 / 245

.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

interviews, public media and publications, and visual inspections�in Vietnam are subsequently carried out to identify the currentsituation of highway bridges in terms of the physical conditionand the maintenance management practice. Collected data arethen carefully analyzed. Problems that need eliminating, there-fore, could be clearly identified. In the next step, severalcomputer-based problem-solving techniques are introduced as apart of the new maintenance management system. They acceleratethe assessment process in an automatic manner. Furthermore, acomputerized database is constructed to have functions of man-agement, maintenance, and assessment for existing bridges inVietnam. At the end, this paper demonstrates an example appli-cation of the system on a specific local condition to test its valid-ity and beneficial outcome.

Current Situation of Highway Bridges in Vietnam

Physical Condition of Highway Bridges in Vietnam

According to statistical data, existing highway bridges in Vietnamconsist of a total 4,107 bridges, running a total length of150,374 m over the entire country �TMoVN 2004�. They are clas-sified by the transport ministry of Vietnam in terms of lengths,materials, construction time, deck widths, and load-carrying ca-pacities. The statistical data shown in Fig. 1�a� confirm that high-way bridges in Vietnam are mostly in the small and medium sizecategories, accounting for 65.72% and 22.55% of the total, re-spectively. Concrete is the most common material used in con-struction, as reinforced concrete and prestress concrete bridgesencompass 59.99% and 20.92% of all bridges �Fig. 1�b��. Manyweak/very weak and narrow/very narrow bridges are still in ser-vice, although they can definitely not satisfy the requirement ofmodern vehicles �trucks, trailers, buses, etc.� where there is de-mand for 25 ton and 14 m width normally. Fig. 1�e� shows28.59% and 18.36% bridges are in the 10 ton and 13 ton load-carrying capacities, respectively. Meanwhile, 31.82% and 45.22%of bridges have traffic lanes less than 6.5 m or from 6.5 to 10 m

Fig. 1. Classification of exi

width �Fig. 1�d��. Bridge ages are in the medium range of

246 / JOURNAL OF BRIDGE ENGINEERING © ASCE / MAY/JUNE 2008

J. Bridge Eng. 2008

10 to 50 years with 52.97% bridges built in the period of 1975–1995 and 33.19% bridges built between 1954 and 1975 �Fig.1�c��.

Existing bridges in Vietnam are generally in poor physicalcondition and have insifficient serviceability. There are severaloutstanding problems that are from not only the bridge structuresthemselves, but also from other aspects of current traffic, the so-ciety, highway routes, etc. According to Hai et al. �2004�, severalcommon types of failure modes, sorted in order of seriousnessand frequency, are: corrosion, fatigue damage, functional obsoles-cence, aging, human invasion, construction defect, missing ele-ment, scouring, settlement, and others. Moreover, Vietnamesehighway bridges have a wide range of shapes, commissioningdates, and have been built by various different design standards�Hai et al., 2007�. Some have been subject to the impact of wars,the adverse climate, and poor maintenance and management con-ditions. Meanwhile, there are differences occurring from geo-graphical locations due to scattering through mountains, deltas,and coasts; the climate in the northern area has four seasons�spring, summer, autumn, and winter� and the southern area onlyhas rainy and dry seasons �TMoVN 2002�. Moreover, a drasticextreme increase in vehicles in terms of volumes and weights hasan adverse impact on the bridge condition. We can assume thatbridges built after 1995 in Vietnam can satisfy current traffic de-mands, as increased safety factors have been used in designstages. However, it seems that many bridges built before 1995 donot satisfy the current transported loads, especially that whichwere affected by wars.

Maintenance Management Practice for HighwayBridges in Vietnam

Bridge Owner and AgenciesThe owner and its agencies for existing highway bridges are or-ganized in hierarchies as shown in Fig. 2. The government ofVietnam is considered as a sole owner due to the function ofproviding finances to initiate, operate, and maintain all bridges

ighway bridges in Vietnam
sting h
throughout their entire lifespan �NAoSRVN 2002�. However, it

.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

does not directly involve itself in detail activities, but empowersthe duty to its subsidiaries, which are distributed across the coun-try with current highway networks. In particular, 50 managementand repair companies are designated as the forefront agencies tomanage and maintain highway bridges in Vietnam. They are pub-lic companies dealing with only public works and are fundedannually from the government to compensate for their operationalcosts.

Bridge ManagementAccording to Hai �2006�, all highway bridges in Vietnam aremanaged by 50 management and repair companies, whose dutiesare: �a� Management of bridge inventory data; �b� inspection andevaluation of bridge health conditions; and �c� security of thetraffic safety and operation. Therefore, these companies are ex-ecuting the bridge management by focusing on the followingthree aspects:1. Inventory management: All bridge-related data have been

handled by untrained staff, and not properly classified norcompiled, since a computerized database system is not avail-able in Vietnam.

2. Bridge site management: Existing bridges are frequentlydamaged by unexpected aliens, such as people, animals, veg-etation, etc., that have adverse impacts. Several importantones are however guarded by in-house staff of the manage-ment and repair companies.

3. Inspection: Bridges are inspected regularly and periodically.Furthermore, they are under special evaluation every3–5 years.

Bridge MaintenanceSite works are carried out to ensure the safety of road users and

Fig. 2. Structural organization of

smooth flow of traffic on highway bridges in Vietnam, and to

JOU

J. Bridge Eng. 2008

maintain their structures at reasonable quality against externalimpacts such as overloads, the climate, and human invasions �Hai2006�. In addition, the owner wishes to preserve structural safetyand traffic capacity as long as possible and reduce the total cost ofexisting bridges by extending their lifespan. On the other hand,the bridge preservation is not executed properly in the practicefield due to the lack of financial aid and attention to the propermaintenance. According to the current regulation in Vietnam�TMoVN 2002�, site maintenance works are classified into threecategories as follows �Fig. 3�:1. Regular maintenance: Carried out every month by in-house

personnel of the managing company under prefixed specifi-cation. It will be continued with the predetermined scheduleand budget.

2. Periodical maintenance: Varies from 2 to 5 years and is themaintenance companies’ responsibility. There are repeatedworks whose time cycles, budgets, scopes, etc., differentlydepend on specific conditions of bridges and their elements.

3. Special maintenance: Uniquely depends on specific condi-tions and must be carried out if bridges are neither physicallysafe nor functionally serving traffic. They are outsourced tocontractors and supervised by the project management units�Fig. 4�.

Outstanding Problems of Highway Bridges in Vietnam

The overview of the physical condition and the maintenance man-agement practice unveils several outstanding problems currentlyoccurring on highway bridges in Vietnam. They are summarizedin terms of physical and management aspects and described

owner and agencies in Vietnam
bridge
below.


.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

Physical Problems1. Highway bridges are generally in poor physical and service-

able conditions with many local defects such as corrosion,fatigue damage, functional obsolescence, aging, human inva-sion, construction defect, missing element, scouring, andsettlement.

2. There are many unsynchronized bridges closely locatedalong the same route tracks whose load-carrying capacityand deck width are very much different. Moreover, bridgesand roads are not homogeneous, as there are many bridgesclassified in weak and narrow categories, while highwayroads are considerably strong and wide.

Management Problems3. The provided annual budget is enough to execute only 30–

50% of the actual demands. Thus, the site maintenance isconducted only on a limited numbers of the bridges.

4. There is a long distance with many hierarchies from bridgeowner �the government of Vietnam� and direct maintenanceagencies �50 companies�. This creates problems of bureau-cracy, communication slowdown, cost acceleration, and soon.

5. A good management system with a computerized database isconsidered as the most important factor for the effectivemaintenance of the bridges, but it has not been applied yet.This leads to several subsequent problems:

a. Inventory data is not properly managed, but is in an

Fig. 3. Categories of site mainte

Fig. 4. Procedure of special main


J. Bridge Eng. 2008

intuitive and manual manner. It is therefore frequently miss-ing and disorderly sorting to cause difficulties for users.

b. There is no systematic method to evaluate currentbridge physical and serviceable conditions as well as theirfuture trends.

c. Site maintenance works are currently executed in equalconsideration and random selection. Priority maintenancecriterion that can assess current demands and allocate thebudget to the most necessary works has not yet been applied.

Outline of the Bridge Management System

General

As outstanding problems have been identified, they must be sooneliminated in order to minimize their adverse impacts on bridgestructures and traffic users. The research therefore constructs anintelligent computerized database named Bridge ManagementSystem of Vietnam �V-BMS�. Functions of this system are to: �a�Manage bridge-related data; �b� assess physical condition andfunctionality of existing bridges; and �c� decide optimal mainte-nance management. If the V-BMS is properly applied, problems 4and 5 can be totally eliminated from existing bridges in Vietnam.On the other hand, problems 1, 2, and 3 are the sole responsibilityof the government of Vietnam, who enables adjusting macropoli-cies for their total elimination. However, if being applied, the

for highway bridges in Vietnam

e for highway bridges in Vietnam

nance

tenanc

.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

V-BMS is expected to minimize adverse impacts of these prob-lems by orienting limited budget in most necessary maintenanceand management works.

The V-BMS also eventually should be applied to the wholepopulation of highway bridges in Vietnam, in the present study, itis applied only to those managed by a single management andrepair company. This is in order to satisfy for local condition: �a�It is used at a tactical level by management and repair companies;�b� it is simple to enable locating at the headquarters and notrequiring either expensive infrastructures �LAN, internet, servers,etc.� or superior knowledge of trained users or complex computerprograms such as Visual C++, Borland C++, and Delphi; and �c� itcan store and run on normal PCs and will not generate high op-erational costs. Fig. 5 shows the structure of the V-BMS to haveconsecutive activities from ¬ to ±. It is controlled by the com-pany’s headquarters through professional moderators for admin-istration, edition, and assessment of data. Authorized personnelenable logging in for information acquisition, but cannot changethe database.

Assessment Techniques

Physical Condition Rating SystemAn expert rating system used to evaluate the actual bridge perfor-mance, based on the knowledge and experience acquired fromdomain experts, will not be applied because of its complexity anduncertainty �Miyamoto et al. 2000�. It is, however, an open optionfor an extended V-BMS version if needed in the future. Instead,the current status of bridges in Vietnam is manually rated byexperienced inspectors, based primarily on information obtainedfrom site observation, nondestructive tests, structural analysis,load tests, etc. The use of manual rating satisfies moreover thepractical condition, where there is low knowledge on the expertrating. In addition, population of bridges managed by a companyis located in a road segment for a short distance up to 300 km.Thus, a small in-house inspector team itself can annually check

Fig. 5. Organization

all bridges to minimize the difference and bias of human judg-

JOU

J. Bridge Eng. 2008

ment. Inspectors’ diagnoses are intuitively performed according toa standard process written as an inspection checklist. This processhas a hierarchical structure in which the ultimate goal is “dura-bility” and “surface appearance” of the whole bridge or its com-ponents. Fig. 6 shows an example of the process to diagnose andjudge for the “surface appearance.” In this process at lower lev-els, inspectors first examine any appearance of damage at bridgesites. Meanwhile at upper levels, they intuitively judge the resultgained from site inspection to determine the current status ofsurface appearance. Final judgment is the conclusion of thebridge condition, which is evaluated according to the “durability”and the “surface appearance.”

According to TMoVN �1998�, the physical condition is ratedinto four levels �Table 1�. At level 0, a bridge is in “excellent”condition, while physical quality and serviceability are not ad-versely impacted by the damage, if any. When there are damages,even not weakening its structures, the bridge is in level I or in“good” condition. Level II indicates a bridge in “moderate” con-dition, if there are damages, those considerably decrease its physi-cal condition and serviceability. A bridge classified as level IIImeans it falls in “poor” condition. In this case, critical defectsappear on the bridge to either cause it to possibly collapse sud-denly or prevent it from serving traffic normally. For levels 0 andI, site maintenance is generally not needed at that moment, exceptfor preventive works. Level II requires corrective maintenance assoon as possible in order to prevent current damage becomingcritical. If a bridge is in level III, its failed components must beurgently remedied, otherwise it will not be safe or functional toserve for normal traffic.

Lifespan EstimationThe expected and remaining lifespan of existing bridges shouldbe approximately estimated to make the right decision for main-taining them in an economically safe condition. However, manydifferent factors that can influence the physical and functionalconditions make difficult to accurately decide the actual lifespan.

cture of the V-BMS
al stru
Yatomi et al. �2004� considered a bridge’s actual lifespan depends


.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

not only on engineering assessment for quality and serviceability,but on social and economical aspects as well. Different viewsreflect different lifespans, thus the entire lifespan of a bridge isestimated in three aspects of physical, serviceable, and economi-cal life �Fig. 7�:1. Physical life �TP�: Due to damage, bridge performance at the

time TP decreases and becomes unable to withstand normaltraffic.

2. Serviceable life �TS�: The function required changes due tothe change in social requirement, the expected function canbe no more realized at the time TS.

3. Economical life �TE�: In cost consideration required to pre-vent the bridge from deterioration, it decides at the time TE

as posting and reconstructing option is more economic thancontinued maintenance and the use of bridge.

Basically, the lifespan is physical life TP as when physicalquality approaches the posting level, the bridge cannot safelyserve traffic users. However, it is not always necessary to be theTP if serviceable and economical factors are concurrently consid-ered. On the one hand, if actual serviceability is unable to accom-modate traffic demand at premature time TS, or the bridgebecomes functionally obsolete, it should be early removed fromservice. In this case, the lifespan is shortened by the time TS toreflect serviceable aspect of bridges. On the other hand, whenmaintenance costs associated are over reconstruction costs, it iseconomical to replace the bridge at the time TE. The lifespan istherefore defined to be the time TE. Though the owner alwayswishes TP, TS, and TE as close as possible, bridges, however, are

Table 1. Rating for the Physical Condition of Existing Bridges in Vietna

Levels Descriptions

0 There are no or minor failures and defects onlimpacting bridges’ structural safety and serv

I There are minor failures and defects, but do nstructural safety and serviceability of bri

II There are failures and defects that currently dimpact on structural safety and serviceability

III There are serious failures and defects that adveon structural safety and serviceability of b

Fig. 6. Process for diagnosis


J. Bridge Eng. 2008

unlikely to have one approximating the others due to unforesee-able climate, traffic, price fluctuation, etc. Therefore, the estima-tion should be annually carried out to evaluate actual deteriorationand to decide an ideal lifespan.

Deterioration PredictionAlthough present performance of a specific bridge can be manu-ally estimated by experienced inspectors, it is not recommendedfor the whole bridge population due to high costs and the time itwould take. Thus, prediction of physical condition and load-carrying capacity are suggested to perform bridge deteriorationanalysis with assistance of computer simulation. In this paper,physical condition encompasses durability as the ability to resistdeterioration and surface appearance, which is defined from totaldamage, execution of works, and serviceability. Meanwhile, load-carrying capacity can be considered as the ability of the bridge towithstand imposed loads of traffic, self-weights, winds, and so on.

The author has constructed his own method to predict physicalcondition and load-carrying capacity for existing bridges in Viet-nam �Hai 2005�. Assumptions were made to clarify for themethod.1. Deterioration of a bridge is drawn as integrated convex

curves according to Eqs. �1� and �2�, because deteriorationprocesses rapidly with the bridge’s age. Vertical axes repre-sent the value of load capacity �LC� and the percentage re-maining of physical condition �PC�, while horizontal axes arefor elapsed time �Fig. 8�. RPC and RLC ��1� are experimentalconstants and t�bridge age. PC100% and LC100%�physical

Need of maintenance

e notity.

Not required.

ken Regular maintenance is required only.

andges.

Regular and periodic maintenance are required.

mpact.

Special maintenance is immediately required.

udgment of bridge condition

m

y; thosiceabil

ot weadges.

evelopof brid

rsely iridges

and j

.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

condition and load-carrying capacity, respectively, when anewly-built bridge enters service. On the other hand, thesevalues, respectively, are PCPosting and LCPosting for the bridgewhen being removed from service

PC = PC�t� = �PC100% − PCPosting��1 − � t

TPC�RPC� + PCPosting

�1�

LC = LC�t� = �LC100% − LCPosting��1 − � t

TLC�RLC� + LCPosting

�2�

2. The deterioration curves start from time 0 when a newly-built bridge enters into service. At that time, the physicalquality is 100% and load-carrying capacity is the value of itsoptimal design load. On the other hand, posting level ismoreover set at the end of the lifespan to remove the bridgefrom service.

3. Site maintenance that has influence on the physical conditionand the load-carrying capacity of bridges is included in thedeterioration prediction.

Life Cycle Cost AnalysisTotal costs associated over the entire lifespan that are needed toconstruct, maintain, and manage a bridge since its initiation untilposting time, should be carefully analyzed. The life cycle cost�LCC� reflects the economical aspect of existing bridges as animportant criterion to decide necessary works. However, there isneither a LCC concept nor its estimation applied in Vietnam now.This part, therefore, analyzes the LCC and applies a methodologyto ensure adequate level of lifetime reliability at the lowest pos-sible cost. The LCC of a bridge, according to Frangopol �1999�,can be expressed in Eq. �3�

LCC = Cinitial + Cmanagement + Cmaintenance �3�

Cinitial�initial cost needed to cover expenses associated withfeasible studies, design, construction, etc. Meanwhile, the man-

Fig. 7. Lifespan estim

Fig. 8. Deterioration curves: Physi

JOU

J. Bridge Eng. 2008

agement fee symbolized as Cmanagement�budget allocated for man-aging existing bridges. Maintenance cost �Cmaintenance� is paid forsite works to either remedy current damages or prevent theiroccurrences. This paper assumes the Cmanagement constantlythroughout the entire lifespan for in-house management. TheCinitial meanwhile is generated prior to year 0, when constructionof newly-built bridges is completed. However, Cmaintenance that isemphasized in the research has changeable values to depend onactual site maintenance. It makes remarkable differences for theLCC and the lifespan if various maintenance options are selected.

In practice, there are many maintenance options applied forexisting bridges. The authors, however, emphasize three main op-tions of changeable Cmaintenance shown in Fig. 9. Option ¬ doesnot require site maintenance throughout the entire bridge lifespan�Cmaintenance=0�. The physical condition and the load-carrying ca-pacity, therefore, degrade freely from 100% to posting level. Inthis option, while LCC1 is minimized for only Cinitial

+Cmanagement, lifespan T1 is however in the shortest time t1. Ifessential maintenance is carried out at time t2 according to option− in order to improve or increase bridge quality, Cmaintenance gen-erates increased total costs to LCC2 and extends lifetime to theT2. Simultaneously, option ® considers an early preventive main-tenance at time t3, even though the bridge is still in reasonablephysical quality and functionality. Total costs increase up toLCC3 and the bridge can last until the T3. Depending on thespecific situation, a suitable option should be selected to enablethe owner financing for required costs and ensuring the physicalquality and the load-carrying capacity certainly above the targetedlevels.

Cost-Benefit AnalysisCost-benefit analysis is an important factor to assist the bridgeauthority selecting maintenance scope. Several specific workswill be selected if they can generate benefit higher than the ex-pense. Oppositely, site maintenance is not carried out with thosethat have a negative result of cost-benefit assessment. In principle,cost-benefit ratio enables evaluating the efficiency of any poten-tial work and selecting the most economical scenario. Therefore,

for highway bridges

ndition and load-carrying capacity

ation

cal co


.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

an important task is to identify the cost �C� and the benefit �B� forany intended maintenance. This study emphasizes the cost-benefitratio of intended maintenance for Cmaintenance and gainedBmaintenance only, but not Cinitial and Cmanagement. Table 2 illustratesthe analysis for three common options:1. The cost: Is Cmaintenance according to Eq. �4�. It was defined as

the total expense to enhance physical and serviceable condi-tions, to prevent potential problems, and to eliminate existingdefects from bridge structures.

C = Cmaintenance = Cpreventive + Ccorrective + Cother �4�

2. The benefit: Is Bmaintenance in term of money value as betterbridge conditions or less future maintenance and failurecosts, higher traffic volumes, etc. are foreseen �Otani et al.,2004�. Total benefit B calculated in Eq. �5� defines the Bvehicle

for the increase of vehicles after site maintenance. TheBtime�time saving as the result of better serviceability. Onthe other hand, if maintenance is not carried out, there is theloss �Bfailure� of users’ delays and detours, structural and ser-viceable depreciation, extra maintenance, and so on

B = Bmaintenance = Bvehicle + Btime + Bfailure + Bother �5�

Maintenance Selection under Budget ConstraintsBased on Priority Algorithm

Currently, highway bridges in Vietnam are in poor physical andserviceable conditions. This, therefore, requires huge amount ofmoney to maintain them. The allocated budget is usually smalland covers only 30–50% of actual maintenance needs, thus thenecessary site maintenance is usually postponed or delayed �Hai2006�. The approval of maintenance does not depend on bridgesonly, but also on other factors such as budget availability, socialpreference, personality, and intuition. The priority for repairingand reinforcing bridges is not specified clearly at the present. Inaddition, site maintenance is equally considered even though ex-

Table 2. Example of Cost-Benefit Analysis

Options Maintenance costs

Do nothing. C=Cpreventive+Cessential+Cother

Essential maintenance. C=Cpreventive+Cessential+Cother=Cessentia

Preventive maintenance. C=Cpreventive+Cessential+Cother=Cpreventiv

Fig. 9. Life cycle cost: ¬ Without maintenance


J. Bridge Eng. 2008

isting bridges differ in location, damage level, circumstance, etc.The current limited budget is therefore not efficiently used toconcentrate on specific bridges for most necessary maintenance.

The priority maintenance index �PMI�, a technique for deter-mining socially preferential maintenance according to bridges’location and its current physical quality is applied. The PMI isspecifically calculated in Eq. �6� for every bridge to base on sev-eral practical factors defined according to logical suggestions ofkey personnel of the bridge owner and its agencies, academicresearchers, and field specialists in Vietnam. BI and BH arebridge importance and health indexes respectively. The �1 and �2

are importance and health factors, respectively, as their total val-ues ��1+�2�=1. As an example for specific conditions of Viet-nam, this paper assumes �1=0.4 and �2=0.6. The purpose of thispaper is to illustrate the computerized database, thus it will notexplain the rationale for the given value of these practical factors.Readers who seek additional information on PMI and values ofpractical factors, can refer to other publications of the author �Hai2005, 2006�. In the course of bridge maintenance planning, thebridges with higher PMI are given higher priority. Thus, the main-tenance works on the bridges with higher PMI are executed inearly years within budget limitations and the work on the bridgeswith lower PMI are postponed

PMI = �1BI + �2BH �6�

Bridge Importance Index (BI)The BI is an index that represents the important charasteristic ofan individual bridge in terms of location, serviceability, and trafficdemand in the road network. It has a maximum value up to 100 inaccordance with Eq. �7� as IL, IW, and IT are practical indexes oflocation, width, and traffic volume, respectively �Table 3�

BI = IL + IW + IT �7�

Maintenance benefits

B=Bvehicle+Btime+Bfailure+Bother=Bfailure+Bother�0

r�0 B=Bvehicle+Btime+Bfailure+Bother�0

er�0 B=Bvehicle+Btime+Bfailure+Bother=Bvehicle+Btime+Bother�0

sential maintenance, ® preventive maintenance

=0

l+Cothe

e+Coth

, − es

.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

Bridge Health Index (BH)The index BH represents physical and serviceable conditions ofthe bridge and is an important indicator in the decision of priority.While healthy bridges need less attention, deteriorated bridgesneed more attention to ensure the safety and function of them. Itsvalue is up to 100 and calculated by Eq. �8�

BH = SF + SV + TP �8�

1. The SF is safe degree of bridge structures with maximumvalue of 50 �Eq. �9��. Values of ai that are safe constants ofcomponent i correlate with the physical condition �level 0:ai=0.25, I: ai=0.50, II: ai=0.75, and III: ai=1�. The si is asafe coefficient of component i with practical values shownin Table 4

SF = �i

aisi �9�

2. The SV is bridge serviceability with a maximum value of 40and calculated by Eq. �10�. bi and svi are serviceable constantand coefficient of criteria i, respectively �Table 5�

Table 3. Values of Location, Width, and Traffic Volume Indexes

Groups Options Values

Bridge location Urban bridges IL=40

National highway bridges IL=35

Provincial road bridges IL=25

District road bridges IL=15

Commune road bridges IL=5

Traffic volume Extremely high with many jams IT=40

High with few jams IT=35

Moderate with or without jams IT=25

Low without jams IT=15

Very low without jams IT=5

Bridge width Very wide �over 17 m� IW=20

Wide �14–17 m� IW=15

Medium �10–14 m� IW=10

Narrow �6.5–10 m� IW=6

Very narrow �less than 6.5 m� IW=3

Table 4. Values of Safe Coefficient si for Specific Components of High-way Bridges

Number Bridge components si

1 Foundations 7

2 Substructures 7

3 Superstructures 7

4 Upper structures 6

5 Auxiliary facilities 2

6 Approach roads 4

7 Pavements 5

8 Joints 2

9 Painting systems 2

10 Traffic safe facilities 2

11 Bearings 2

12 Drainage systems 2

13 Waterproof systems 1

14 Others 1

JOU

J. Bridge Eng. 2008

SV = �i

bisvi �10�

3. The TP is considered as the bridge impact on third partieswith a maximum value of 10. ci and tpi are third party con-stant and coefficient i, respectively �Eq. �11� and Table 6�

TP = �i

citpi �11�

Practical Demonstration of the V-BMS

The V-BMS is constructed on personal computers using MS Ac-cess and MS Excel languages. In the present study, it is specifi-

Table 5. Values of Serviceable Constant bi and Serviceable Coefficientsvi

Criteria svi Classifications bi

Deck widths 10 Very wide �over 17 m� 1.0

Wide �14–17 m� 0.8

Medium �10–14 m� 0.6

Narrow �6.5–10 m� 0.4

Very narrow �less than 6.5 m� 0.2

Load carryingcapacities

10 Very strong �30 ton� 1.0

Strong �25� 0.8

Medium �18� 0.6

Low �13� 0.4

Very low �10� 0.2

Deck surfaces 10 Level III 1.0

Level II 0.75

Level I 0.5

Level 0 0.25

Approach roads 5 Bridge deck is poorer than approach road. 1.0

Bridge deck is fit in approach road. 0.6

Bridge deck is better than approach road. 0.2

Others 5 Poor serviceability. 1.0

Moderate serviceability. 0.6

Good serviceability. 0.2

Table 6. Values of Third Party Constant ci and Coefficient tpi

Criteria tpi Classifications ci

Clearance space 5 Frequently prevent vessels undercrossing. 1

Sometimes prevent vessels undercrossing. 0.6

Not prevent vessels undercrossing. 0.2

Bridge location 3 Urban areas. 1

National highways. 0.8

Provincial roads. 0.6

District roads. 0.4

Commune roads. 0.2

Physical condition 1 Level III 1

Level II 0.75

Level I 0.50

Level 0 0.25

Others 1 High impact to third party. 1

Moderate impact to third party. 0.6

Low impact to third party. 0.2


.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

Table 7. List of Existing Highway Bridges Belonging to the Management and Repair Company X

Bridgecode

Bridgename

Width�m�

Length�m�

Loadcapacity

Built�Year�

B-1 Bridge 1 37.5 66.8 30 Ton 1998

B-2 Bridge 2 12.1 5.7 30 Ton 1986

B-3 Bridge 3 11.8 170.3 30 Ton 1985

B-4 Bridge 4 12.0 16.7 30 Ton 1976

B-5 Bridge 5 12.0 12.7 30 Ton 1976

B-6 Bridge 6 11.0 68.0 30 Ton 1991

B-7 Bridge 7 12.0 19.1 30 Ton 1976

B-8 Bridge 8 12.0 23.3 30 Ton 1976

B-9 Bridge 9 12.0 20.0 30 Ton 1976

B-10 Bridge 10 12.0 28.1 30 Ton 1976

B-11 Bridge 11 12.0 18.2 30 Ton 1980

B-12 Bridge 12 11.6 59.0 30 Ton 1978

B-13 Bridge 13 12.6 26.3 30 Ton 1977

B-14 Bridge 14 12.6 14.2 30 Ton 1976

B-15 Bridge 15 13.0 23.2 30 Ton 1976

B-16 Bridge 16 12.2 5.7 30 Ton 1977

B-17 Bridge 17 12.0 21.1 30 Ton 1978

B-18 Bridge 18 12.0 27.5 30 Ton 1978

B-19 Bridge 19 12.0 18.5 30 Ton 1978

B-20 Bridge 20 12.0 21.2 30 Ton 1978

B-21 Bridge 21 12.9 26.6 30 Ton 1978

B-22 Bridge 22 16.1 61.6 30 Ton 1994

B-23 Bridge 23 7.9 13.8 25 Ton 1964

B-24 Bridge 24 9.0 47.9 25 Ton 1970

B-25 Bridge 25 9.5 30.0 30 Ton 1995

B-26 Bridge 26 5.5 24.4 25 Ton 1965

B-27 Bridge 27 5.5 24.4 25 Ton 1965

B-28 Bridge 28 9.4 42.2 13 Ton 1967

B-29 Bridge 29 7.6 17.6 13 Ton 1967

Fig. 10. Output screens for: management subdatabase and bridge inventory data


J. Bridge Eng. 2008.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

cally applied in the management and repair company X as a dem-onstrated example for the validity of the system. The companyexecutes the management and maintenance works of the 29 ex-isting bridges on the 150 km national highway segment of Viet-nam �Table 7�. The V-BMS consists of three interlinked modules,subdatabase for management, subdatabase for assessment, andsubdatabase for maintenance. At first, the bridge-related inventorydata such as physical condition state, serviceability, maintenanceworks, and surrounding condition are collected and stored in thesubmodules for management and maintenance. Next, it estimatesseveral important criteria, such as the remaining life, the presentstate of deterioration, the life-cycle costs and cost-benefit analy-sis, as well as priority maintenance index by computer simulationand expert opinion allocated in the assessment module. TheV-BMS then lists up the scope of maintenance works and associ-ated costs in the order of priority for the following year. Finally,authorized in-house staff decide the scope of maintenance worksfor the next fiscal year based on the budget availability, trafficconditions, and social requirements, by referring to the results ofanalysis.

Bridge Management Module

The output screen of the management module shown in Fig. 10indicates general information of codes, names, locations, struc-tural types, etc. to help the V-BMS users quickly allocate a bridgein its population. Furthermore, detailed data stored into low hier-archy levels of policies, inventory data, external conditions, con-struction and design documents, historical incidents, and otherinformation are interlinked with the main management screen.

Bridge Assessment Module

From several theories and calculated methods presented in theprevious section, the V-BMS assesses and simulates actual bridgeconditions and their future trends for lifespan estimation, deterio-ration prediction, LCC, cost-benefit analysis, and PMI. The resultis all plotted on computer screens as examples shown in Fig. 11

Fig. 11. Output screen for the lifesp

and Table 8.

JOU

J. Bridge Eng. 2008

Table 8. Maintenance Priority Order and Costs for Bridges Managed bythe Company X

Bridgecode

Bridgename

Priority index�PMI�—order

Maintenancecosts �VND�

B-1 Bridge 1 60.17�14� 5,000,000

B-2 Bridge 2 85.21 �1� 1,300,000

B-3 Bridge 3 65.49�10� 16,800,000

B-4 Bridge 4 58.83�16� 2,700,000

B-5 Bridge 5 52.16�23� 1,600,000

B-6 Bridge 6 72.31 �5� 6,700,000

B-7 Bridge 7 53.61�21� 2,900,000

B-8 Bridge 8 51.28�24� 1,800,000

B-9 Bridge 9 55.67�17� 500,000

B-10 Bridge 10 75.11 �4� 2,600,000

B-11 Bridge 11 62.85�11� 3,600,000

B-12 Bridge 12 49.86�27� 9,000,000

B-13 Bridge 13 50.96�26� 1,100,000

B-14 Bridge 14 54.57�18� 2,100,000

B-15 Bridge 15 69.25 �6� 4,700,000

B-16 Bridge 16 53.57�20� 900,000

B-17 Bridge 17 58.96�15� 2,800,000

B-18 Bridge 18 49.17�28� 3,600,000

B-19 Bridge 19 78.63 �2� 8,700,000

B-20 Bridge 20 60.34�13� 1,800,000

B-21 Bridge 21 68.15 �8� 4,100,000

B-22 Bridge 22 48.72�29� 1,300,000

B-23 Bridge 23 76.74 �3� 5,600,000

B-24 Bridge 24 52.67�22� 500,000

B-25 Bridge 25 51.17�25� 6,900,000

B-26 Bridge 26 62.58�12� 2,300,000

B-27 Bridge 27 68.67 �7� 1,400,000

B-28 Bridge 28 54.93�19� 7,100,000

B-29 Bridge 29 65.81 �9� 2,700,000

Total required maintenance cost 112,100,000

an estimation and deterioration prediction

Note: VND is Vietnamese Dong, the official currency of Vietnam.


.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

Fig. 12. Output screen

Fig. 13. Output screen

for the maintenance records

for the scopes of maintenance
Bridge Maintenance Module256 / JOURNAL OF BRIDGE ENGINEERING © ASCE / MAY/JUNE 2008
J. Bridge Eng. 2008.13:245-257.

Dow

nloa

ded

from

asc

elib

rary

.org

by

Flor

ida

Atla

ntic

Uni

vers

ity o

n 09

/19/

13. C

opyr

ight

ASC

E. F

or p

erso

nal u

se o

nly;

all

righ

ts r

eser

ved.

Maintenance-related data of existing bridges are located into thismodule as examples of the maintenance records �Fig. 12� and themaintenance selection for next fiscal years �Fig. 13�. It storesinformation of past and in-progress maintenance regarding theirscopes, locations, costs, etc. By supervising site works, in-housestaff and moderators enable collecting all this information to inputinto the database. Meanwhile, the provided annual budget isenough to execute only 30–50% of the actual demands. It is im-possible for the management and repair companies to carry out allthe maintenance work, and only on a limited numbers of thebridges. The V-BMS moreover divides site maintenance intocompulsory and selective works. The compulsory maintenanceencompasses tasks that must be urgently carried out in order toensure minimum allowable levels of safety and serviceability.Meanwhile, the selective maintenance is noncritical tasks cur-rently. However, if the budget is available, they should be carriedout soon in order to prevent the occurrence of potential problemsin the future.

Conclusions

This paper introduces a practical maintenance management sys-tem �V-BMS� for highway bridges in Vietnam. By reviewing thecurrent status of existing bridges in terms of the physical qualityand the maintenance management practice, two physical and threemanagement problems are clearly identified. On the other hand,several advanced assessment techniques such as lifespan estima-tion, deterioration prediction, life cycle cost analysis, cost-benefitanalysis, and maintenance priority index are also included in theproposal. A computerized database, considered as the most impor-tant core of the V-BMS, is therefore constructed to consist ofmodules of management, assessment, and maintenance. The paperconsiders if the system is properly applied, it can eliminate twomanagement problems, and minimize adverse impacts of the re-maining problems. In order to make the V-BMS compliant withthe practical condition of Vietnam, the study simplifies the com-puterized database to apply at a tactical level and does not requireexpensive infrastructures or superior knowledge. It therefore canrun in normal PCs and will not generate high operational costs.Demonstration of the V-BMS on computer screens for a specificmanagement and repair company in Vietnam is further illustratedto prove the validity of the new maintenance management system.

The V-BMS has been pilot tested since late 2005 to a specificmanagement and repair company in Vietnam. The smooth opera-tion of the computerized database was undoubted evidence of itsvalidation on actual maintenance management practice for exist-ing bridges in Vietnam. It enables reducing significantly in-housestaff assigned to management of inventory data, quicklyinputting/outputting updated information related to bridges, andappropriately assessing physical and serviceable conditions aswell as priority maintenance order for the whole bridge popula-tion. Moreover, the test has proved the simplification of the data-base and does not require expensive infrastructures. This is a veryimportant aspect to feasibly apply to Vietnam, a developing coun-try that currently lacks know-how personnel and financial
sources.
JOU

J. Bridge Eng. 2008

In order to execute a successful application of the V-BMS forthe whole bridge population, the recommendation is to carry outfurther practical validations on various actual conditions of Viet-nam. Necessary modification of the system may be needed forseveral groups of bridges that differ from geographical condition,the climate, imposed traffic, society, and so on. The influence ofpractical factors into the maintenance priority index should beconsidered too to accurately eliminate man-made errors of theV-BMS. Moreover, training for in-house staff in charge of han-dling the new system is recommended to smoothly run the modelof maintenance management system on specific conditions ofVietnam. Further research needs also to make the V-BMS morerobust with better automatic functions and to apply it to allbridges in the country by setting up linkages with all maintenanceagencies.

References

Chase, S. B., Gaspar, L. �2000�. “Modeling the reduction in load capacityof highway bridges with age.” J. Bridge Eng., 5�4�, 331–336.

Dac, L. H., He, P. V., and Hoc, B. X. �2004�. “Current conditions ofconcrete bridges in Vietnam and the needs of maintenance, and im-provement.” The National Research Program Code DTDL 2003/04,Vietnam.

Frangopol, D. M. �1999�. “Life-cycle cost analysis for bridges.” Bridgesafety and reliability, D. M. Frangopol, ed., ASCE, Va., 210–236.

Hai, D. T. �2005�. “Initiating a method of priority factor for maintenanceof road-bridges in Vietnam.” Trans. J. Vietnam, 7, 56–57.

Hai, D. T. �2006�. “Maintenance management system for existingbridges—An explorative study for Vietnam and Japan.” Ph.D. thesis,Yokohama National Univ.

Hai, D. T., Yamada, H., and Katsuchi, H. �2004�. “Existing bridge con-ditions in Vietnam: Current failures and their causes.” Proc., BridgeMaintenance, Safety, Management, and Costs, IABMAS 04, Kyoto,Japan, 337–339.

Hai, D. T., Yamada, H., and Katsuchi, H. �2007�. “Present condition ofhighway bridges in Vietnam: An analysis of current failure modes,and their main causes.” J. Struc., Infrastruct. Eng., 3�1�, 61–73.

Miyamoto, A., Kawamura, K., and Nakamura, H. �2000�. “Bridge man-agement system and maintenance optimization for existing bridges.”Comput. Aided Civ. Infrastruct. Eng., 15�1�, 45–55.

National Assembly of the Social Republic of Vietnam �NAoSRVN�.�2002�. “Law of land transportation of Vietnam.”

Otani, Y., Fujii, H., Takahashi, Y., Kaneuji, M., Furuta, H. �2004�. “Acase study on asset management for concrete bridges.” Proc., BridgeMaintenance, Safety, Management and Costs, IABMAS 04, Kyoto,Japan, 93–95.

Transport Ministry of Vietnam �TMoVN�. �1998�. Technical proceduresin evaluating highway bridges 22TCN. 243–98, Transportation PressHouse, Hanoi, Vietnam.

Transport Ministry of Vietnam �TMoVN�. �2002�. The works of manage-ment, maintenance and repair of roads and bridges in Vietnam, Trans-portation Press House, Hanoi Vietnam.

Transport Ministry of Vietnam �TMoVN�. �2004�. Transportation infra-structure of Vietnam in 2003, Transportation Press House, Hanoi,Vietnan.

Yatomi, M., Takahashi, J., Baba, H., Kohinata, T., Fuji, A. �2004�. “Ap-plication of risk-based maintenance on materials handling system.”
IHI Eng. Rev., 37�2�, 52–58.

.13:245-257.

computerized database for maintenance and management of highway bridges in vietnam

Documents