Jurnal Teknik Sipil

Studi Identifikasi Daerah Sebaran Banjir di DAS Peusangan dengan Pemodelan HEC-RAS 2D Unsteady Flow

2025-11-21T11:14:18+07:00

Abstract

The Peusangan Watershed is a watershed located in Aceh Province. According to data from the Aceh Irrigation Agency, the downstream area of the Peusangan Watershed frequently experiences flooding, resulting in environmental damage and significant economic losses. Flood management efforts that have been undertaken include the construction of retaining walls. Furthermore, studies are needed to assess the inundation conditions, including flood inundation modeling using HEC-RAS 2D unsteady flow software and ArcGIS 10.5 for mapping the affected areas. The modeling results indicate that the flood inundation areas for return periods of 2, 5, 10, 25, 50, and 100 years are, respectively, 37,38 km², 78,13 km², 95,17 km², 112,82 km², 120,67 km², and 126,28 km². The model validation of flood distribution points for each return period was 28,57%, 66,67%, 71,43%, 76,19%, 90,48%, and 90,48%, respectively. The mapping results based on the classification of downstream sub-districts with return periods of 2, 5, 10, and 25 years inundated two sub-districts, namely Peusangan Selatan Sub-district and Peusangan Siblah Krueng Sub-district, while the return periods of 50 and 100 years inundated three sub-districts, including Peusangan Sub-district.

Keywords : Flood, Peusangan Watershed, arcgis, HEC-RAS 2D.

Efektivitas Drainase Vertikal sebagai Mitigasi Likuefaksi dalam Ragam Potensi Percepatan Tanah Maksimum

2025-02-06T15:17:16+07:00

Abstract

Lolu Village, located in the Palu Koro fault groove and has a stratification of soil sediment that is layered with heterogeneous characters. Between the cohesive and granular soils, forming an overlapping layer. Lolu Village has its own challenges in dealing with the potential for earthquakes and liquefaction as a result. One of the liquefaction mitigations in SNI 8460:2017 is stone columns (SC) as a vertical drainage medium that functions to accelerate the rate of pore water dissipation. However, the condition of the layered soil interspersed with cohesive soil with low permeability, presents its own challenges in determining the depth of stone columns. It is necessary to review the extent of the effectiveness of SC against Peak Ground Accelerations (PGA) that have the potential to occur in Lolu Village. The stratification of the soil and stone columns will be modelled using the Midas GTS NX. Soil layers with liquefaction potential use the UBC Sand model and SC with the Mohr Coulomb model. When the stratification modeling of the soil was shaken by cyclic loads, it was found that only the upper granular layer was liquefaction. This identifies that the thin layer of cohesive soil between the layers of granular, has a role as a shield to resist the pore water pressure of the granular soil layer underneath. The study compared the initial soil conditions against two variations in the depth of SC. It was found that the depth of the SC was passed through the thin layer of cohesive soil between the granular layers, worsening the liquefaction condition of the upper layer.

Keywords : Liquefaction, Midas GTS NX, Pore Pressure Ratio PPR, stone columns

Analisis Kinerja Campuran Panas Open Graded Friction Course (OGFC) Menggunakan Asbuton Murni Dengan Modifier Elvaloy (PG 82)

2025-12-01T15:38:15+07:00

Abstract

This study aims to evaluate the performance of Open Graded Friction Course (OGFC) mixtures using Asbuton Murni modified with Elvaloy polymer (PG 82). The research focuses on analyzing asphalt binder characteristics and assessing the resistance of the mixture to functional distress (raveling) and structural distress (rutting and fatigue). The optimum asphalt content was determined in accordance with ASTM D7064/D7064M-08 through Void in Mix (VIM), Cantabro Loss, and draindown tests. Furthermore, the mixture performance was evaluated using Indirect Tensile Fatigue Test (ITFT) and Hamburg Wheel Tracking Device (HWTD) tests.

The test results indicate that the G/sin δ* value increased from 77.5 °C to 84.5 °C, signifying improved resistance to permanent deformation. In addition, the mixing and compaction temperatures decreased, thereby enhancing the workability of the mixture. The OGFC Asbuton–Elvaloy mixture satisfied the requirements for raveling resistance and exhibited a high dynamic stability of 37,526 passes/mm, exceeding the specifications of Bina Marga. However, the fatigue performance remained relatively low, with fatigue lives of 25,186 cycles at 250 kPa and 3,375 cycles at 400 kPa.

These findings demonstrate that the OGFC Asbuton–Elvaloy mixture performs well in terms of resistance to permanent deformation but has not yet fully met the criteria for a structural pavement layer. Therefore, this study recommends further development of the OGFC Asbuton–Elvaloy mixture so that it may function not only as a functional layer, but also has the potential to be developed as a structural pavement layer, with performance comparable to Bina Marga (2018) specifications for AC-WC and SMA pavements..

Keywords : Asbuton murni, Elvaloy, OGFC, VIM, Cantabro, asphalt draindown, fatigue, HWTD, rutting, dynamic stability.

Pelimpah ITB Golden Ratio: Inovasi Geometri Mercu Pelimpah untuk Kemudahan Perencanaan dan Kinerja Hidraulis yang Baik

2025-09-17T16:19:12+07:00

Abstract

A spillway is a critical hydraulic structure used to release excess water when the water surface elevation in a dam exceeds the normal limit. The discharge capacity is strongly influenced by its geometric profile. In Indonesia, ogee and circular spillways are the most commonly used types. The ogee spillway is known for its superior hydraulic performance but features a complex geometry that requires high construction precision. In contrast, the circular spillway offers a simpler design, yet lacks a standardized reference for crest curvature ratios. To address this issue, the Golden ratio Tipe Spillway was developed by applying the constant mathematical ratio φ ≈ 1.618 to the crest profile. The aim is to create a design that is simpler, visually harmonious, and still hydraulically efficient. Evaluation was conducted through numerical simulations using Flow 3D software, validated by physical model testing in the laboratory. Results show that while the ogee spillway remains the most optimal in terms of performance, the ITB Golden Ratio Spilway types A and B demonstrate comparable discharge capacity, safe pressure.

distribution, and low cavitation risk. These advantages make it a practical and reliable design alternative

Keywords: Spillway crest, Flow-3D, physical model test, spillway design, ITB Golden ratio spilway.

Analisis Tarif Jalan Tol Yogyakarta–Bawen Berdasarkan Sensitivitas Volume Lalu Lintas Terhadap Perubahan Tarif

2025-12-03T16:07:26+07:00

Abstract

Determining toll road rates is an important factor for the sustainability of investment and optimal benefits for users. This study analyzes the sensitivity of traffic volume to rate changes on the Yogyakarta–Bawen Toll Road using secondary data from PT Jasa Marga (Persero) Tbk and PT Jasamarga Jogja Bawen. The methods used include Ability to Pay (ATP) and Willingness to Pay (WTP) determination, time value determination, and macro transportation modeling with PTV Visum. The results show that an increase in toll rates reduces traffic volume, but there is an optimum point that generates maximum revenue. The optimal toll rates for Class I vehicles is projected to be IDR 1,400/km in 2029 and IDR 2,130/km in 2039, assuming that the time value follows inflation. These findings indicate that higher toll rates during the initial operational phase do not necessarily result in maximum toll revenue, thus requiring periodic evaluation of the toll setting policy.

Keywords : Toll road, toll rate, traffic volume sensitivity, toll revenue, traffic modelling.