Pemetaan Parameter Lapisan Tanah Menggunakan Metode HVSR (Horizontal to Vertical Spectral Ratio) di Wilayah Surabaya

Widyaningrum, Giantrise (2026) Pemetaan Parameter Lapisan Tanah Menggunakan Metode HVSR (Horizontal to Vertical Spectral Ratio) di Wilayah Surabaya. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Wilayah Surabaya secara umum tersusun atas endapan aluvial kuarter berupa material sedimen lunak yang memiliki potensi memperbesar gelombang seismik di permukaan. penelitian ini bertujuan untuk mengetahui distribusi spasial parameter seismik seperti frekuensi natural (f0), faktor amplifikasi (A0), dan indeks kerentanan seismik (Kg), serta menganalisis karakteristik struktur lapisan bawah permukaan berdasarkan hasil inversi kurva HVSR. Pengukuran mikrotremor dilakukan pada 20 titik yang tersebar mulai dari Surabaya utara hingga timur. Hasil kurva HVSR yang didapatkan menunjukkan puncak yang jelas dan dapat dilanjutkan ke tahap analisis. Hasil analisis menunjukkan estismasi sebaran nilai frekuensi natural (f0) berada pada rentang 1,1 Hz hinga 2,6 Hz, yang menunjukkan bahwa wilayah Surabaya tersusun dari lapisan sedimen lunak dengan ketebalan yang cukup besar. Nilai estimasi faktor amplifikasi (A0) memiliki rentang 1,2 hingga 5,2, yang menunjukkan bahwa terdapat bagian dengan nilai rendah dan sebagian lainnya tinggi. Estimasi indeks kerentanan seismik (Kg) yang didapat memiliki rentang 1,02 hingga 18,50, yang menunjukkan bahwa Surabaya memiliki kerentanan rendah hingga sedang. Hasil inversi kurva HVSR menunjukkan profil tanah wilayah penelitian dengan model tiga lapisan dengan half space di bawahnya. Nilai Vs30 yang didapatkan diperkirakan berada pada rentang 99,77 m/s hingga 627,77 m/s yang menunjukkan bahwa wilayah Surabaya berada pada rentang nilai rendah hingga tinggi. Keseluruhan hasil penelitian menunjukkan bahwa wilayah penelitian memiliki tingkat kerentanan seismik yang perlu diperhatikan.
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Surabaya area is generally composed of kuarternary alluvial deposits in the form of soft sediment materials that have the potential to amplify seismic waves at the surface. This study aims to determine the spatial distribution of seismic parameters such as natural frequency (f0), amplification factor (A0), and soil vulnerability index (Kg), as well as to analyze the characteristics of the subsurface layer structure based on the results of HVSR curve inversion. Microtremor measurements were carried out at 20 points distributed from northern to eastern Surabaya. The results of the HVSR curve obtained a clear peak and can be continued to the analysis process. The analysis results show that the estimated distribution of natural frequency (f₀) values ranges from 1.1 Hz to 2.6 Hz, suggesting that the Surabaya region is composed of soft sediment layers with considerable thickness. The estimated amplification factor (A₀) values range from 1.2 to 5.2, indicating that some areas have low values while others have high values. The estimated seismic vulnerability index (Kg) ranges from 1.02 to 18.50, indicating that Surabaya has low to moderate vulnerability. The results of HVSR curve inversion reveal the soil profile of the study area with a three-layer model underlain by a half-space. The Vs30 values obtained are estimated to range from 99.77 m/s to 627.77 m/s, indicating that the Surabaya region falls within a low to high value range. The overall findings of this study indicate that the study area exhibits a level of seismic vulnerability that warrants attention.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Amplification Factor, HVSR, Natural Frequency, Soil Vulnerability Index. Faktor Amplifikasi, Frekuensi Natural, Indeks Kerentanan Seismik
Subjects:	Q Science > QC Physics Q Science > QE Geology > QE538.5 Seismic tomography; Seismic waves. Elastic waves Q Science > QE Geology > QE538.8 Earthquakes. Seismology Q Science > QE Geology > QE539 Microseisms. Q Science > QE Geology > QE539.2.S4 Seismic models
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Physics > 45201-(S1) Undergraduate Thesis
Depositing User:	Giantrise Widyaningrum
Date Deposited:	21 Jul 2026 02:09
Last Modified:	21 Jul 2026 02:09
URI:	http://repository.its.ac.id/id/eprint/135909

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