Kajian Hidraulis pada Alternatif Desain Spillway di Bendungan Cabean, Kabupaten Blora

Lusianawati, Pipit (2026) Kajian Hidraulis pada Alternatif Desain Spillway di Bendungan Cabean, Kabupaten Blora. Diploma thesis, Institut Teknologi Sepuluh Nopember.

Text 2036221023-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (20MB) | Request a copy

Abstract

Bendungan Cabean di Kabupaten Blora direncanakan sebagai infrastruktur pengendali banjir sekaligus pendukung irigasi dan penyediaan air baku. Sebagai bangunan yang berfungsi menyalurkan debit banjir secara aman, spillway (pelimpah) perlu dievaluasi tidak hanya dari sisi kapasitas debit, tetapi juga kelayakan hidraulisnya. Penelitian ini bertujuan untuk mengetahui dan membandingkan kinerja hidraulis spillway tipe labyrinth sebagai desain eksisting dengan desain alternatif tipe labyrinth (modifikasi) dan tipe morning glory pada Bendungan Cabean. Analisis dilakukan melalui dua tahap, yaitu perhitungan hidraulis secara teoritis/empiris dan pemodelan numerik menggunakan Computational Fluid Dynamics (CFD), yang mencakup kajian pada saluran samping, saluran transisi, saluran peluncur, dan kolam olak, dengan parameter tinjauan berupa tinggi jagaan, bilangan Froude, potensi dan bahaya kavitasi, aliran getar, panjang loncatan hidraulis, serta gerusan hilir. Hasil analisis menunjukkan bahwa pelimpah eksisting tipe labyrinth telah memenuhi seluruh kriteria desain, meskipun pemodelan CFD mengindikasikan adanya vortex pada belokan saluran transisi yang dapat direduksi melalui modifikasi radius belokan sebesar 1,5 m. Desain alternatif labyrinth menunjukkan kinerja hidraulis yang lebih baik dibandingkan eksisting, terutama pada rasio antara debit banjir sungai dan debit pelepasan (Qsungai/Qrelease) dan panjang loncatan hidraulis yang lebih pendek, sementara desain alternatif morning glory unggul pada tinggi jagaan dan tingkat keamanan terhadap kavitasi. Berdasarkan evaluasi dan pembobotan parameter hidraulis, desain alternatif labyrinth spillway memperoleh nilai tertinggi dan direkomendasikan sebagai desain pelimpah terbaik untuk diterapkan pada Bendungan Cabean.
=======================================================================================================================================
Cabean Dam in Blora Regency is planned as flood control infrastructure that also supports irrigation and raw water supply. As a structure functioning to safely convey flood discharge, the spillway needs to be evaluated not only in terms of discharge capacity but also its hydraulic feasibility. This study aims to determine and compare the hydraulic performance of the labyrinth-type spillway as the existing design with alternative designs of a modified labyrinth type and a morning glory type at Cabean Dam. The analysis was conducted in two stages, namely theoretical/empirical hydraulic calculations and numerical modeling using Computational Fluid Dynamics (CFD), covering the side channel, transition channel, chute channel, and stilling basin, with review parameters including freeboard, Froude number, cavitation potential and hazard, flow vibration, hydraulic jump length, and downstream scouring. The analysis results show that the existing labyrinth-type spillway has met all design criteria, although CFD modeling indicates the presence of a vortex at the transition channel bend, which can be reduced through a 1.5 m modification of the bend radius. The alternative labyrinth design demonstrates better hydraulic performance than the existing design, particularly in terms of the ratio between river flood discharge and release discharge (Qriver/Qrelease) and a shorter hydraulic jump length, while the alternative morning glory design excels in freeboard and cavitation safety level. Based on the evaluation and weighting of hydraulic parameters, the alternative labyrinth spillway design obtained the highest score and is recommended as the best spillway design for implementation at Cabean Dam.

Item Type:	Thesis (Diploma)
Uncontrolled Keywords:	Bendungan Cabean, Computational Fluid Dynamics (CFD), Morning glory, Labyrinth Weir, Cabean Dam, Spillway
Subjects:	T Technology > TC Hydraulic engineering. Ocean engineering > TC555 Spillways. Energy dissipation. Hydraulic jump.
Divisions:	Faculty of Vocational > 22301-Civil Infrastructure Engineering (D4)
Depositing User:	Pipit Lusianawati
Date Deposited:	04 Aug 2026 05:02
Last Modified:	04 Aug 2026 05:02
URI:	http://repository.its.ac.id/id/eprint/142532

Actions (login required)

View Item