The feasibility study of bridge construction plan in Digoel River Province of Papua

Abstract

The planning of the bridge construction in Digoel river that connects the western part with the eastern part of Boven Digoel in Papua Province is part of the development program as stipulated in PP No 78 Tahun 2014 about" Acceleration of development in underdeveloped regions". The land, river, and air transport systems that connect between regions in Boven Digoel are very difficult to be reached, also to extreme weather and climate conditions make the transportation cost expensive. One of the efforts to overcome these problems is to build road and bridge infrastructure. To support the implementation of infrastructure development in the district of Boven Digoel, a feasibility study of road and bridge planning is required. It refers to the guidelines Pd T-19-2005-B (Studi Kelayakan Proyek Jalan dan Jembatan). A feasibility study was undertaken to analyze in more detail some of the proposed road trace alternatives. Based on the feasibility study results, two alternatives of road trails connecting the western and eastern part of Boven Digoel of Papua Province are chosen. The bridge plans were made across the Digoel river. Bridge construction on alternative road trails connecting Kampung Ampera with Tanah Merah is considered to be more effective and efficient because it is safer from river scouring hazard. The bridge length is made longer than the width of the Digoel river, considering the rapid changes of the channel size. From the results of field measurement analysis, the average speed of the movement of the horizontal river flow direction is (80-180) x10(-4) meters/day so that in the 50-year period, the movement speed of the horizontal river flow path becomes (160 - 3200) meters. Based on Kun Qarshov method, the movement of the river flow for 50 years at the location of the bridge connecting Tanah Merah through Ampera Village is 311.64 meters so that the optimum bridge length at the location is designed 600 meters.