Claim Missing Document
Check
Articles

Found 4 Documents
Search

Seismic Site Classification Using the Multichannel Analysis of Surface Waves Method Syamsuddin, Erfan; Aswad, Sabrianto; Assegaf, Muhammad Alimuddin Hamzah; Rasimeng, Syamsurijal; Sakka, Sakka; Syamsuddin, Syamsuddin; Nasri, Muhammad; Syihab, Mufly Fadla
POSITRON Vol 12, No 2 (2022): Vol. 12 No. 2 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v12i2.53869

Abstract

The soil has a variety of qualities that affect its ability to support the weight of a structure. One of these features is soil stiffness, which can be determined using the surface wave method to prevent soil collapse. Multichannel Analysis of Surface Waves (MASW) is one of the non-invasive methodologies used in this study to investigate subsurface structures in North Sumatra, Indonesia. This method utilizes the dispersion properties of Rayleigh waves, producing a dispersion curve to get the shear wave velocity (Vs) through inversion. The shear wave velocity can be used to examine the soil stiffness qualities. The dispersion curve explains the relationship between shear wave velocity and depth, which can subsequently be used as a site class parameter. This survey uses three lines with one shot for each line which uses thirty geophones. The seismic source used is a gun with the type M16.38 Cal. Each line consists of 30 geophones with a distance of 5 m. The entire track is 160 m long and lasts for 2048 seconds with a sampling rate of 0.00025 seconds. The average shear wave velocity measured at three measurements was 372.5 m/s on line P1, 347.1 m/s on line P2A, and 311.0 m/s on line P2B, respectively. Overall, the soil classification on the P1 line is class C, and the P2A and P2B lines are class D, which is suitable for development planning areas.
Assessing soil vulnerability in Petobo post-liquefaction zone, Palu, Central Sulawesi: A microzonation study utilizing microtremor measurements Syamsuddin, Erfan; Maulana, Adi; Hamzah, Alimuddin; Irfan, Ulva Ria
Journal of Degraded and Mining Lands Management Vol. 11 No. 3 (2024)
Publisher : Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15243/jdmlm.2024.113.5805

Abstract

On September 28, 2018, a 7.5 Richter magnitude earthquake struck the Palu City neighborhood of Petobo. The tectonic activity along the Palu-Koro fault generated this earthquake, which resulted in soil liquefaction. The purpose of this study is to use microtremor measurements at 33 distinct places to investigate the properties of the soil layer after liquefaction. The obtained data was then evaluated utilizing Horizontal to Vertical Spectral Ratio (HVSR) methodologies such as Ground Shear Strength (GSS), amplification factor, and vulnerability index to determine the soil layer's properties and susceptibility. The dominant frequency ranges from 0.19 to 4.75 Hz, while the dominant period ranges from 0.21 to 5.17 seconds, according to the measurement results. According to these measurements, the silt layer varies between 5 and 30 m. GSS values in the 10-4 to 10-2 range indicate that soil cracking, subsidence, liquefaction, landslides, and compaction are likely. The soil vulnerability and amplification index values range from 2.36 to 4.37, respectively. These values show the potential level of danger, which might be low, medium, high, or extremely high. Peak ground acceleration varied from 299.52 to 301.52 gals, suggesting high to extremely high danger levels. The microzonation map created for this study is considered to be a useful resource for training disaster mitigation approaches and facilitating infrastructure development planning in the region.
Integrating electrical resistivity tomography and x-ray fluorescence for characterizing limestone in the Wapulaka Formation, Central Buton, Indonesia Syamsuddin, Erfan; Maulana, Adi; Assegaf, Alimuddin Hamzah; Irfan, Ulva Ria
Journal of Degraded and Mining Lands Management Vol. 12 No. 4 (2025)
Publisher : Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15243/jdmlm.2025.124.7871

Abstract

The Wapulaka Formation in Central Buton, Indonesia, is a tectonically complex carbonate system characterized by heterogeneous lithologies, including limestones, dolostones, and marls. This study integrates Electrical Resistivity Tomography (ERT) and X-Ray Fluorescence (XRF) to map the subsurface distribution and geochemical characteristics of limestone in the formation. Electrical Resistivity Tomography (ERT) surveys were conducted along four profiles, covering a total length of 495 meters, with an electrode spacing of 5 meters to identify resistivity variations linked to lithological changes, fractures, and karst formations. The collected data were processed and inverted with Res2DInv software, applying topographic corrections to produce high-resolution 2D resistivity models. The limestone samples were examined with an Epsilon 4 XRF spectrometer to ascertain the elemental concentrations, particularly the CaO and MgO levels. Borehole data were used to validate ERT findings and provide a lithological perspective. The amalgamation of the ERT and XRF datasets demonstrate a robust correlation between resistivity and chemical composition. High-resistivity zones (>5000 ?m) are associated with significant, high-purity limestone characterized by elevated CaO and reduced MgO levels, while low-resistivity regions (<1000 ?m) signify eroded, porous, or clay-rich portions with increased MgO and diminished CaO content. The Mg/Ca ratio, obtained from XRF analysis, acts as an indicator of dolomitization, with higher ratios linked to decreased resistivity values. This technology facilitated the creation of a predictive model for limestone quality utilizing resistivity, enhancing resource assessments and selective mining efficacy. This study illustrates the efficacy of integrating geophysical and geochemical methods to delineate intricate carbonate systems, providing insights into subsurface heterogeneity, diagenetic processes, and resource availability.
Optimizing maize cultivation through Fuzzy AHP: Balancing land suitability, land use, and environmental sustainability Arif, Samsu; Baja, Sumbangan; Nurmiaty, Nurmiaty; Syamsuddin, Erfan; Syamsuddin, Syamsuddin
Journal of Degraded and Mining Lands Management Vol. 12 No. 4 (2025)
Publisher : Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15243/jdmlm.2025.124.8219

Abstract

This study optimized maize cultivation in Gowa Regency, South Sulawesi, Indonesia, a tropical region with diverse topography and environmental constraints, by integrating Fuzzy Analytical Hierarchy Process (Fuzzy AHP) and spatial autocorrelation analysis to assess land suitability. Using a two-stage Fuzzy AHP, 12 criteria (e.g., slope, landslide risk, rainfall) were normalized via fuzzy membership functions and weighted through expert pairwise comparisons in a GIS framework, with spatial autocorrelation identifying clustering patterns. A 30-meter resolution dataset covering topographic, soil, climatic, land use, and environmental risk factors, prioritized slope, landslide risk, and rainfall, yielding a consistent model (CR = 0.0093). The suitability map classified 1.35% (2,445 ha) as highly suitable (S1), 18.1% (32,868 ha) as moderately suitable (S2), 49.1% as marginally suitable (S3), and 31.45% as unsuitable (N). Spatial autocorrelation (Moran’s I = 0.81, p = 0.001) revealed S1/S2 hotspots in the northern plains, ideal for maize expansion, and N coldspots in the eastern highlands, limited by steep slopes and landslide risks. Overlay analysis highlighted land-use conflicts, with moderately suitable land in settlements and unsuitable land in nature reserves, underscoring the need for integrated planning. The framework prioritizes low-risk S1/S2 hotspots for cultivation, restricts high-risk zones, and promotes sustainable practices like terracing and agroforestry for marginal lands. This replicable methodology offers policymakers and farmers actionable insights to enhance maize productivity while ensuring environmental resilience in tropical landscapes. Policymakers should enforce zoning to protect S1/S2 hotspots and subsidize sustainable practices.