The Influence of the New LRT Pier to the Sedimentation Pattern Around Ampera Bridge in Musi River, South Sumatera, Indonesia

Abstract

Sedimentation rate, which is the most important parameters of the inland water way performance like Musi River becoming one of a major research topic in Indonesia. The influence of additional pier for the new LRT Bridge constructed parallel to Ampera Bridge to the sedimentation pattern of Musi River was discussed in this paper. Currently, as most of the rivers in Indonesia, a complete field data observation of discharge, sediment characteristic is a luxury one to have. That's why mathematical model, supported by eligible limited field measurements for model calibration and verification, is commonly used to predict the above parameters. Hydrometric survey of water level, sediment samples (both suspended and bed sediment), velocity and bathymetry were conducted to get instantaneous field data. Based on the comparison of two bathymetry map with difference periods of measurements, it was found that the sedimentation rate, was different for high and low tide. Tank model of Sacramento and USLE were used to respectively generate synthetic river discharge and soil surface erosion rate. Hydrodynamic model of SMS 8 was used to predict annual rate of sedimentation. Good comparison of the field measurement and SMS model results was found for current and sediment pattern. The maximum sedimentation occurs during the high tide where the backwater was generated by sea intrusion. The New LRT pier increase the impact of river contractions for both maximum velocity around the Ampera Bridge up to 1.5 time and sedimentation rate behind the pier group of the bridges.

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“…Stability. As part of the substructure portion, the main function of piers is to sustain vertical load and horizontal force from the superstructure (Supriyadi, Siswosukarto & Hadjoh, 2017;Kusuma, Mohammad, Habibi, Yasin & Johan, 2020). Thus, pier stability has a profound effect on influencing slenderness limits at ultimate and serviceability limit states (ULS and SLS) including construction phases, as well.…”

“…Local scouring forecasting. One of the most often investigated unfavourable phenomena is local scouring in the region of pier (Kusuma et al, 2020). Researchers underline the importance of local scouring research, as a great danger for stability loss, while emphasizing the role of flow rate as a factor determining the size of scour size and shape parameters.…”

“…Researchers underline the importance of local scouring research, as a great danger for stability loss, while emphasizing the role of flow rate as a factor determining the size of scour size and shape parameters. The role of the need to calculate the predicted parameters of the local scour hole already at the design stage of the structure is emphasised in order to avoid costly overhauls and reconstructions in the future (Sarminingsih, Soekarno, Hadihardaja & Kusuma, 2014;Amin, Sarino, Haki, 2017;Kusuma et al 2020). The formation of local scour is particularly acute in the context of the disastrous flood flows that Indonesia is facing especially often (Triatmadja, Hijah & Nurhasanah, 2011;Armono & Budipri-yanto, 2013;Asian Development Bank, 2016;Wijayanti, Zhu, Hellegers, Budiyono & van Ierland, 2016).…”

“…The average flow of 2,500 m 3 •s -1 as well as backwater due tide influence in the region of bridge. The most of the maximum flood and sedimentation around that bridge occur during high tide period, invoking local scour phenomenon (Kusuma et al, 2020). Moreover high-performance drainage system is used in the bridge construction.…”

Trend Analysis of Rainfall, Land Cover, and Flow Discharge in the Citarum Hulu–Majalaya Basin

“…However, Gunawan et al [37] had done a study about reasonable results of sedimentation rate prediction for the river with a lack of data observation using a neural network method. Another study had conducted by Kusuma et al [38] using a twodimensional mathematical model. Improving the contribution of river normalization to flood risk reduction may also require an improvement in flood hazard model prediction.…”