scholarly journals Ambient Noise Analysis During Nyepi in Denpasar Using Horizontal-to-Vertical Spectral Ratio (HVSR) Method

2020 ◽  
Vol 18 (1) ◽  
pp. 23
Author(s):  
I Putu Dedy Pratama ◽  
Dwi Karyadi Priyanto ◽  
Pande Komang Gede Arta Negara
Keyword(s):  
Ambient Noise ◽  
Seismic Vulnerability ◽  
Amplification Factor ◽  
Noise Analysis ◽  
Spectral Ratio ◽  
Vulnerability Index ◽  
Dominant Frequency ◽  
Before And After ◽  
Hvsr Method ◽  
Index Value

Nyepi Day is a unique tradition where outdoor human activities stop 24 hours a day. Denpasar City is the region that has the most significant impact on this change because it is the capital province. This study aims to determine the effect of Nyepi on ambient noise in Denpasar on March 25, 2020. We installed a TDS sensor at the Denpasar Geophysics Station for 3x24 hours ie when Nyepi Day, before and after Nyepi as comparative data. The data is processed by the HVSR method to get the value of dominant frequency and amplification factor every hour. Compared to the day before and after Nyepi, the dominant frequency increased during Nyepi and the amplification factor decreased during Nyepi. Seismic vulnerability index value at Nyepi is 24 where there is a decrease of index 3,904 with a day before and after Nyepi. This is showed that Nyepi Day affected ambient noise in Denpasar.

scholarly journals Studi Mikrotremor dengan Metode Horizontal to Vertical Spectral Ratio (HVSR) di Tapak RDE, Serpong

EKSPLORIUM ◽  
2019 ◽  
Vol 40 (2) ◽  
pp. 105
Author(s):  
Eko Rudi Iswanto ◽  
Yuni Indrawati ◽  
Theo Alvin Riyanto
Keyword(s):  
Seismic Vulnerability ◽  
Nuclear Reactor ◽  
Amplification Factor ◽  
Power Reactor ◽  
Spectral Ratio ◽  
Vulnerability Index ◽  
Historical Records ◽  
Hvsr Method ◽  
Subsurface Investigation ◽  
Selection For

ABSTRAKBencana alam seperti kejadian gempa bumi dapat menyebabkan kerusakan pada area tapak dan infrastruktur termasuk fasilitas reaktor nuklir. Fenomena ini perlu dipahami secara komprehensif melalui catatan sejarah karakteristik dinamik tapak. Penggunaan mikrotremor dengan metode Horizontal to Vertical Spectral Ratio (HVSR) telah digunakan secara luas dalam investigasi bawah permukaan sejak satu dekade terakhir. Tujuan penelitian ini adalah mengetahui karakteristik geologi setempat dan karakteristik dinamis bawah permukaan. Penelitian ini mengaplikasikan penggunaan mikrotremor metode HVSR di tapak Reaktor Daya Eksperimental (RDE) di Serpong. Pengukuran dilakukan di 15 lokasi, kemudian data diolah dengan metode HVSR menggunakan perangkat lunak Geopsy. Hasil analisis menunjukkan bahwa Tapak RDE mempunyai nilai frekuensi dominan antara 3,06 Hz–23,27 Hz dan faktor amplifikasi 1,84–6,37. Bagian timur laut dan tenggara tapak memiliki indeks kerentanan seismik yang lebih tinggi dibandingkan dengan bagian lainnya. Oleh karena itu, pilihan lokasi gedung reaktor di area barat daya sudah tepat kerena memiliki faktor amplifikasi, ketebalan sedimen, dan indeks kerentanan seismik yang relatif rendah.ABSTRACTNatural disaster like earthquake can cause damage to the site and the infrastructure including nuclear reactor facilities. This phenomenon needs comprehensively understood through its dynamic characteristics historical records of the site. The use of Horizontal to Vertical Spectral Ratio (HVSR) method has been widely used for subsurface investigation since last decade. The aimed of the research is to obtain local geological and subsurface dynamic characetristics. This research is applying the use of HVSR method for Experimental Power Reactor (RDE) in Serpong. The measurements are in 15 locations, and then the data is processed by using Geopsy software. The analysis result shows that the RDE site has dominant frequncy values between 3.06 Hz–23.271 Hz and amplification factor 1.84–6.37. The northeast and southeast areas of the site have higher seismic vulnerability index than in other area. Therefore, the selection for reactor bulding location in the southwest area is proper because it has lower amplification factor, sedimen thickness, and seismic vulnerability index.

scholarly journals Microzonation of Cisarua District Using Horizontal Vertical Spectral Ratio

2021 ◽  
Vol 5 (2) ◽  
pp. 88-94
Author(s):  
Elrangga Ibrahim Fattah ◽  
Keyword(s):  
Amplification Factor ◽  
Active Faults ◽  
Spectral Ratio ◽  
Dominant Frequency ◽  
Research Area ◽  
Geological Structure ◽  
Eurasian Plate ◽  
Hvsr Method ◽  
Microtremor Measurement ◽  
Tectonic System

The Bandung region is part of the framework of the Indonesian tectonic system, namely the tectonic plate meeting zone, where the Indo Autralia plate is infiltrated under the Eurasian plate in a convergent manner. The subduction process produces an effect in the form of an active fault geological structure in the Bandung area. One of these active faults is the Lembang Fault, which has a length of ± 29 kilometers and a shear acceleration of 3 to 5.5 millimeters per year. The microtremor measurement method is a passive geophysical method that utilizes natural subsurface vibrations so that it can provide dominant frequency data and amplification factors for soil layers. Based on the results of seismic susceptibility research using microtremor measurements using the HVSR method in the Lembang Fault zone in Cisarua Sub-District, it can be seen that the distribution of the dominant frequency values tends to be influenced by lithology and topography. In the research area, it is known to have a dominant frequency value that varies due to the different types of lithological units. In general, the dominant frequency ranges from 1-3 Hz because it is dominated by tuff sand and tuff pumice, and areas composed of volcanic breccias have a dominant frequency value between 3-6 Hz. Meanwhile, the amplification factor value will be influenced by rock deformation and weathering. The area that has a very high amplification factor value is in the southeast of the study area with an A0 value greater than 5. This indicates that the area is composed of a layer of thick and not dense tuff sand

scholarly journals PEMETAAN MIKROZONASI SEISMIK DI DESA NUNKURUS KECAMATAN KUPANG TIMUR KABUPATEN KUPANG

2018 ◽  
Vol 2 (2) ◽  
pp. 66-74
Author(s):  
Roswita T. Saman ◽  
Hery L. Sianturi ◽  
Redi K. Pingak
Keyword(s):  
Peak Ground Acceleration ◽  
Seismic Vulnerability ◽  
Single Point ◽  
Vulnerability Index ◽  
Dominant Frequency ◽  
Seismic Microzonation ◽  
Ground Acceleration ◽  
Index Value ◽  
Frequency Magnitude

ABSTRAK  Telah dilakukan penelitian mikrozonasi seismik di desa Nunkurus Kecamatan Kupang Timur Kabupaten Kupang. Penelitian ini bertujuan untuk mengetahui  nilai frekuensi dominan tanah, nilai ampifikasi, indeks kerentanan tanah dan percepatan tanah serta membuat peta indeks kerentanan tanah dan peta. Berdasarkan hasil penelitian diperoleh nilai frekuensi dominan tanah berkisar antara 0.293 Hz – 18.41 Hz, nilai amplifikasi berkisar antara 1,68–8,52, nilai indeks kerentanan seismik  berkisar antara 0,3285 –179,23556 dan nilai PGA berkisar antara 107,77488 gal-218,62941 gal sehingga dapat dikatakan bahwa daerah penelitian berada dalam kawasan yang cukup aman karena hanya sebagian titik saja yang memiliki nilai frekuensi, nilai amplifikasi, nilai indeks kerentanan dan nilai PGA yang besar. Kata kunci : Mikrozonasi, HVSR, Nunkurus  ABSTRACT  The research about seismic microzonation in Nunkurus village, sub-district of east Kupang, district of Kupang has been done. The aims of this research are to determine the values of soil dominant frequency, magnitude of amplification, seismic vulnerability index, the peak ground acceleration and to make seismic vulnerability index map and PGA map. The results showed that the values of the the values of the dominant frequency was about 0,293 Hz – 18,41 Hz, the amplification about 1,68 – 8,52. Meanwhile, the index of vulnerability was found to be 0,32853 – 179,23556  and peak ground acceleration values about 107,77488 gal - 218,62941 gal so it can be said that the area of ​​research is safe enough because only a single point that has the frequency value, the value of amplification, the index value of vulnerability and PGA great value. Keywords : Microzonation, HVSR, Nunkurus

scholarly journals Local Site Effects Evaluation Using Microtremor Measurements at North Side of Pandan Mountain

2017 ◽  
Vol 1 (2) ◽  
pp. 89 ◽  
Author(s):  
Samsul Hidayat ◽  
Dwa Desa Warnana ◽  
Sorja Koesuma ◽  
C Cari
Keyword(s):  
Natural Frequency ◽  
Amplification Factor ◽  
Spectral Ratio ◽  
Vulnerability Index ◽  
Disaster Mitigation ◽  
Residential Areas ◽  
Weak Zone ◽  
Local Site ◽  
Index Value ◽  
The Impact

Disaster mitigation has been undertaken to reduce the impact of loss or damage caused by the earthquake. For disaster mitigation purpose, it is necessary to conduct a local geological assessment. The horizontal to vertical spectral ratio (HVSR) of microtremor analysis is very popular in the context of seismic micro-zonation. Microtremor method is cheap, data acquisition is easy, and does not cause noise, so suitable for use in residential areas. This research aims to determine the distribution of the natural frequency value, the amplification factor value, and the soil vulnerability index value. This study was conducted geographically between 7°26'17.45" – 7°26'53.16" S and 111°47'14.76" – 111°48'7.06" E. Data processing using HVSR analysis method on Easy HVSR software. The results showed that the natural frequency (<em>f<sub>o</sub></em>) values range 0,95 Hz to 8,3 Hz and the amplification factor values range 2,05 to 8,67. From the result data of the natural frequency and the amplification factor, the soil vulnerability index can be calculated. The vulnerability index (Kg) value ranges from 1,09 to 68,33. The northeast side of the study area is indicated as a weak zone where have high potential to damage when the earthquake occurred.

scholarly journals The Soft Layer Thickness Estimation using Microtremor Measurement to Identify Landside Potential in Watukumpul, Central Java, Indonesia.

2021 ◽  
Vol 6 (1) ◽  
pp. 16-23
Author(s):  
Urip Nurwijayanto Prabowo ◽  
Akmal Ferdiyan ◽  
Ayu Fitri Amalia
Keyword(s):  
Layer Thickness ◽  
Spectral Ratio ◽  
Dominant Frequency ◽  
Soil Slope ◽  
Soft Layer ◽  
Thickness Estimation ◽  
Central Java ◽  
Hvsr Method ◽  
Microtremor Measurement ◽  
Potential Area

Watukumpul is an area that is prone to landslides, so determining the soft layer thickness is very important to identify the landslide potential. The soft layer thickness can be estimated using microtremor signal measurements which analyzed using the Horizontal to Vertical Spectral Ratio (HVSR). In this study,we measured microtremor signal of 33location around Watukumpul, Pemalang, Central Java area to determine soft layer thickness. Micretremor signal was analyzed based on theHVSR method using Geopsy software and follow the standard of the Sesame Europan Project. The results of the HVSR method are the HVSR curve that fulfills the reliable curve standard. HVSR curve shows that the dominant frequency of soft layer ranges from 1.36 – 7.62 Hz and the amplification values ranges from 9.00 – 41.45. The soft layer thickness value in the study area ranges from 17.58 - 103.60 meters. The high landslide potential area are located at W7, W8, W18, W30 and W32 where has thin soft layer and high soil slope.

scholarly journals ANALISIS TINGKAT RESIKO DAMPAK GEMPABUMI DI KABUPATEN CILACAP MENGGUNAKAN METODE DSHA DAN DATA MIKROTREMOR

2020 ◽  
Vol 4 (3) ◽  
pp. 73-89
Author(s):  
Kukuh Dialosa ◽  
Rustadi Rustadi ◽  
Bagus Sapto Mulyatno ◽  
Cecep Sulaeman
Keyword(s):  
Hazard Analysis ◽  
Soil Layer ◽  
Spectral Ratio ◽  
Dominant Frequency ◽  
Soil Class ◽  
Land Type ◽  
Short Period ◽  
Hvsr Method ◽  
Ability Factor ◽  
Microtremor Measurement

Soil mechanical research has been done in Cilacap Regency using DSHA method and microtremor data. This study aims to analyze the local land response to earthquakes based on the dominant frequency parameters (f0), amplification factor (A0), wave velocity VS30 and seismic hazard analysis through deterministic approach. This research uses 193 microtremor measurement points using a short period TDS-303 type (3 component) seismometer. Microtremor data were analyzed using the Horizontal to Vertical Spectral Ratio (HVSR) method in geopsy software. DSHA analysis refers to the source of the Lembang Fault earthquake and Java Subduction zone for deterministic calculations. Based on the analysis of HVSR method, Cilacap Regency is located on land type 1 (frequency 0-1.33 Hz) and soil type 2 (frequency 1,33-5 Hz) according to Kanai Classification (1983), dominated amplification value 1,104 to 8,171 times, then Dominated by soil class E (VS30 value 183 m / s) and soil class D (183 m / s VS30 366 m / s) according to NEHRP Classification (2000). This indicates that Cilacap Regency has high vulnerability to earthquake disaster. Based on the estimated value of PGA calculation method of DSHA, from the calculation of earthquake source Subduction obtained Java PGA bedrock 0,045 g - 0,0671 g and PGA surface rock 0,1926 g - 0,4855 g and calculation of Lembang Fault obtained PGA bedrock 0, 09 g - 0.025 g and PGA surface rocks 0.017 g - 0.089 g. Based on risk map analysis (combination of dominant frequency analysis, amplification, susceptibility factor and ability factor), the highest risk areas are Kec. Adipala, Kasugihan, Binangun, Nusawungun, Cil. Middle, Cil. South, Cil. North, allegedly the soil layer constituent area is a layer of thick and soft sediments. While the low risk of Kec. Majenang and Dayeuh Luhur.

scholarly journals Analisis Shear Strain dan Kerusakan Bangunan Akibat Gempa Bumi di Kecamatan Gading Cempaka dan Ratu Agung Kota Bengkulu

2018 ◽  
Vol 2 (2) ◽  
pp. 222-226
Author(s):  
Kurnia Lestari ◽  
Muchammad Farid ◽  
Afrizal Mayub
Keyword(s):  
Shear Strain ◽  
Land Surface ◽  
Amplification Factor ◽  
Dominant Frequency ◽  
Building Damage ◽  
Entire Area ◽  
Hvsr Method ◽  
Geological Formation ◽  
Formation Type ◽  
The Relationship

ABSTRACT  [The Analysis of Shear Strain and Building Damage due to Earthquake at Gading Cempaka and Ratu Agung District in Bengkulu City]. The aims of this research are to: (1) determine and mapping the distribution of shear strain values, (2) correlate between shear strains with building damage Gading Cempaka and Ratu Agung caused by earthwuake at sub district in Bengkulu city. Microtremor data were taken at 108 observation points then analyzed using HVSR method to obtain amplification factor and dominant frequency values..The result showed that shear strain value of Gading Cempaka and Ratu Agung sub district in Bengkulu city are relatively heterogeneous although in the same geological formation type. The earthquake in 2007 is estimated to be 3.38% potential to deform the land surface in the form of fractures and settlements and 96, 62% potentially experience shocks due to waves and vibrations due to earthquake. The earthquake of 2000 estimated that almost the entire area of Gading Cempaka and Ratu Agung has the potential to experience shocks due to waves and vibrations due to earthquake that is equal to 97% while potentially liquefaction (ambles) occurs by 3%. The correlation between shear strain with the damage of buildings due to earthquake shows the relationship is directly proportional to the function y = 15267x + 26.219 with the coefficient of resgression of    = 0.671. Keywords:  Earthquake;  HVSR method;  microtremor;  shear strain.

Estimation of Site Dynamic Characteristics from Ambient Noise Measurements Using HVSR Method in Microzonation Study: Senggarang, Batu Pahat, Malaysia

2014 ◽  
Vol 931-932 ◽  
pp. 803-807 ◽  
Author(s):  
Ahmad Fahmy Kamarudin ◽  
Mohd Effendi Daud ◽  
Zainah Ibrahim ◽  
Ibrahim Azmi ◽  
Mohamad Khairani Yub ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Ambient Noise ◽  
Hazard Analysis ◽  
Resonance Effect ◽  
Spectral Ratio ◽  
Boundary Area ◽  
Contour Maps ◽  
The North ◽  
Hvsr Method ◽  
Noise Measurements

Site dynamic characteristics evaluation of fundamental ground frequency, Fo and amplification factor, Ao in Senggarang region were presented in 2D and 3D contour maps (microzonation maps) based on the ambient noise measurements carried out using Lennartz 1 Hz tri-axial seismometer sensors. Reliability of Fo and Ao determined from the ambient noise technique has become the main key components in seismic hazard analysis, resonance effect assessment, predictions of sedimentary layer and shear wave velocity, through cheaper, non-destructive and quick methodology. 73 points of ambient noise records were analyzed using Horizontal-to-Vertical Spectral Ratio (HVSR) method in the boundary area of 800 m x 800 m with the grid spacing of 100 m x 100 m. Significant peaks of mean HVSR curves were checked against the criterions proposed by the SESAME guideline. Slight difference of the Fo contours pattern between the North-South (NS) and the East-West (EW) directions was observed, but vice versa to the Ao contours between both directions. Significant peaks of Fo values were distributed from 1.61 to 6.35 Hz, whereas the Ao values were found from 3.18 to 9.39. Wide gap between the ranges of Fo and Ao in respective direction have shown to the variation of sediment thicknesses. Meanwhile, dominance shape of significant peak from the HVSR curves may indicate to a large velocity contrast presence underneath the ground surfaces.

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