Abstract:
abstract. PT Adaro Indonesia is trying to adjust a vertical clearance under Tabalong Bridge 1
(unloaded) and Tabalong Bridge 2 (loaded) because the existing conditions still apply a
minimum vertical clearance of 4 m. It should be in accordance with latest Regulation of the
Minister of Public Works No. 19/PRT/M/2011 that for vertical clearance above national road at
least 5.1 m. This specification has not been met by the national road under the Tabalong 1 & 2
Bridges because both bridges were built in the 90s. Therefore we need an engineering
technique to overcome this. There are 2 alternative designs, namely lowering the elevation of
the national road and increasing the elevation of the bridge's upper structure to mitigate
oversized vehicles so as not to hit the lower structure of the Tabalong bridge. In determining
the selection of the best alternative designs in this research is based on two (2) things, nonfinancial
criteria with Analytical Hierarchy Process (AHP) and financial criteria with Life
Cycle Cost Analysis (LCCA)/Benefit Cost Ratio (BCR) method. This study uses a survey
method by distributing questionnaires and interviews as a means of collecting primary data. In
addition, previous research and consultant DED documents were used as a means of collecting
secondary data. The AHP method is used to process primary data to produce a decision from a
non-financial aspect. While the LCC/BCR method is used to process secondary data to produce
a decision from the financial aspect. The results of the AHP analysis obtained that the synthesis
value of the decision the option of lowering national roads was 85% and the bridge lifting
option was 15% and the consistency ratio (CR) was 0.05 < 0.1. The consistency ratio below 0.1
shows that the questionnaire data from the respondents are consistent. The results of the
analysis of Life Cycle Cost (LCC) obtained the option of lowering national roads where the
LCC value is Rp. 44,877,651,669.27 more economical than the bridge lifting option. Then the
results of the Benefit Cost Ratio (BCR) analysis obtained the option of lowering national roads
with a BCR value of 2.33 > 1 and NPV = Rp. 43,442,264,804.34 > 1 means that the option
lowering national roads is feasible. While the bridge lifting option is obtained by analyzing the
value of BCR = 0.98 < 1 and NPV = - Rp. 1,435,386,864.92 < 1 means that the bridge lifting
option is not feasible to implement.
