IMPLEMENTATION OF BRIDGE MANAGEMENT SYSTEM ON INTERURBAN BRIDGE IN MALUKU PROVINCE

Bridges as transport infrastructures play a vital role in smoothing traffic flows. The performance of a bridge in playing its role and serving its function depends on its management. The Government, through the Directorate General of Highways of the Ministry of Public Work has used a system to manage bridges known as the Bridge Management System (BMS). The system allows a systematic plan and provides a uniform procedure for all bridge operation activities on the national and provincial level. Data from Implementation Agency of National Inter-Urban Roads of Area IX, Maluku—Northern Maluku in 2011 indicates that the total length of national roads in Maluku Province is 15,238.01 m. It consist of 562 bridges in total. In Ambon Island, especially, there are 52 bridges whose overall length is 1176 m. The study was conducted at several inter-urban bridges in Maluku Province of Ambon Island: Wai Batu Merah, Wai Ruhu, Wai Lawa, Wai Yari and Wai Tua Bridge. The assessment of bridge structure conditions was conducted visually to determine the conditions of the existing bridges comprehensively by referring to the Bridge Management System (BMS) complemented with a computer-based Bridge Management Information System (BMIS). The assessment results show that the condition scores for Wai Batu Merah, Wai Ruhu, Wai Lawa, Wai Yari, and Wai Tua bridges are 2, 1, 2, 1, and 2, respectively. According to Directorate of Bina Marga, the scores of the five bridges indicate that it is physically in a good condition or in a minor defect. The higher score indicates the poorer condition. Based on technical screening, the proposed treatment for Wai Batu Merah, Wai Ruhu, Wai Lawa, and Wai Tua Bridge is the rehabilitation on their sub-elements. Regarding the Wai Yari Bridge, it should be regularly maintained. The defect repair costs are IDR 149,138,238; IDR 81,048,000; IDR 174,579,106; IDR 79,233,324.and IDR 238,323,258; for Wai Batu, Wai Ruhu, Wai Lawa, Wai Yari, and Wai Tua Bridges, respectively.


INTRODUCTION
Considering the importance of bridges, bridge assessment needs to be conducted to provide safety and convenience for the bridge user.Based on the data from Implementation Agency of National Inter-Urban Roads of Area IX, Maluku-Northern Maluku in 2011, the total length of national roads in Maluku Province is 15,238.01m.It consist of 562 bridges in total.In Ambon Island, especially, there are 52 bridges whose overall length is 1,176.25 m.Therefore, the objectives of this research are to study the conditions of bridges connecting inter-urban roads in Maluku province, i.e.Wai Batu Merah, Wai Ruhu, Lawa, Yari, and Wai Tua bridges using BMS; to determine the treatment plant that corresponds to the bridge condition scores obtained from technical screening; and also to evaluate a budget plan that accord with bridge damage repair plan.The assessment of bridge defects was conducted visually.

BMS MANAGEMENT INFORMATION SYSTEM (BMS MIS)
The bridges are parts of the land transport infrastructure that are vital in the traffic flow.The bridges are also frequently served as critical components of a road because they determine the maximum load of vehicles passing through the road.
In general, bridge damages that result in the breakdown of traffic flow may paralyze the transportation that in the end disrupts the economy (Triwiyono, 2011a;Triwiyono, 2011b).
The BMS MIS contains a database of bridges and a computer program which allow to entry and retrieval of inspection and other data, to be used as bridges standard report and to make a list of bridges rank or screening the preparation of maintenance and rehabilitation program.

Detailed Inspections
Detailed inspections are carried out to assess the condition of a bridge and its elements in order to prepare the treatment program for each bridges and rank bridges in term of priority for treatment.

Element Rating System
The Element Rating System for defective element consists of a series of 5 questions about the defects present.These questions are concerned with the following aspects: a) Structure: whether the structure is harmful or harmless.b) Degree : whether the failure is minor or major c) Extensive : whether the defect is extensive or not extensive i.e. does it exist in more or less than 50% of the element by length, area or volume d) Function : whether the elements still function or not e) Effect: The defective element seriously influences other elements or the flow of traffic.
A score of either 1 or 0 is allocated to the element in respect of each defect present, according to the criteria shown in Table 1 (Directorate General of Bina Marga, 1993a;1993b;1993c;1993d;2008).

Screening and Technical Ranking of Bridges
The general screening criteria can be seen in Table 2 with the given value followed Directorate of Bina Marga (1993a;1993b;1993c;1993d;2008).

Data Analysis
The primary and secondary data were subsequently processed using a computer program that developed in according to Bridge Management Information System (BMIS).After screening, the data were processed to obtain the technical ranking of bridge.

Time and Tools
The current research was conducted from September 8 th 2012, to December 8 th 2012.Tools and materials which were used to conduct this research were detailed inspection report form, papers, and pencils, measuring device (meter), camera, flashlight, personal computer, Bridge Management Information System (a software).

RESULTS AND DISCUSSION
The result of visual field observation can be seen in Table 3.The comparison of bridge condition for five observed bridges can be seen in Table 4. Based on the technical screening result, as shown in Table 5, it is suggested that rehabilitation of the bridge sub elements should be conducted.IDR 81,048,000.00,IDR 174,579,106.10,IDR 79,233,324.01 and IDR 238,323,258.60 for Wai Batu, Wai Ruhu, Wai Lawa, W ai Yari, and Wai Tua Bridges, respectively.Thus , the total cost for the five Bridges is IDR 722,381,965.00.

Suggestions
Herewith the suggestions are proposed that may be fruitful for the bridge management research.
a) BMS program is in need of improvement by widening its compatibility so that it can be run on Windows operating systems.
b) Technical screening is a sorting out of bridges, a process carried out by BMS computer program based on 2 categories, i.e. condition scores and traffic capacity, excluding load score/load capacity.It is hoped that the scoring system will be more widely used.

Table 1 .
Determination of condition mark

Table 2 .
General screening criteria

Table 4 .
Bridge condition score comparison matrix The result of economic evaluation of each bridge for sub-element rehabilitation are Wai Tua Bridge ranks in the 1 st priority; Wai Lawa Bridge ranks in the 2 nd priority, Wai Batu Merah Bridge ranks in the 3 rd priority, Wai Ruhu Bridge rank in the 4 th priority.The economic evaluation was not be conducted on Wai Yari Bridge because it is categorized as the one that need routing maintenance.d) The defect repair costs are IDR 149,138,238.00,