Determination of The Site Amplification on Deep Soil Layer Using 1-D Site Response Analysis (Case study: Jakarta City, Indonesia)

The dynamic response of deep soil layers is used in the development of microzonation maps. The empirical correlation between standard penetratation blow count numbers and S-wave velocity was derived for practical purposes in site characterization based on local data in a case study in Jakarta, Indonesia. For estimating the intensity of potential earthquake shaking at the ground surface as a function of depth to the bedrock surface layer, 1-D site response analysis was carried out in 5745 simulations. The site amplification values were then evaluated by dividing the spectral acceleration (SA) at ground surface by the SA at rock outcrop. Plots of the SA amplification values at interested depth intervals of the bedrock surface layer were assigned. The results showed that the site amplification values estimated by considering the local depth of the bedrock surface layer were generally smaller than the SA amplification values from the Indonesian seismic building code SNI-1726-2012. Also, there appears to exist a tendency of lower levels of mean regression of amplification, in particular for the soft soil site class

Zonasi Hazard Gempa Bumi Untuk Wilayah Jakarta

Several damaging earthquakes occured in the last decades in Indonesia have alerted the government to mitigate future damages due to earthquake. One of method to minimize the damages is by performing seismic hazard assessment and risk evaluation as the hazard zonation with respect to ground motion characteristics taking into account sources, local geological and soil conditions. This paper performs a microzonation study for Jakarta. Local site effects are assessed by carrying out ground response analysis performed with the NERA routines. The zonation maps are produced with respect to ground shaking intensity in accordance with the manual proposed by World Institute for Disaster Risk Management

Studi Kehandalan Selubung Respons Spektrum Kelas Tanah Lunak Zona 5 untuk Daerah Meukek, NAD

Abstrak. Indonesia merupakan negara dengan aktivitas seismik yang tinggi sehingga perencanaan bangunan harus memperhitungkan aspek-aspek kegempaan. Suatu teknik analisis resiko gempa dapat dilakukan berdasarkan kriteria desain yang disyaratkan SNI 03-1726-2002, yaitu untuk umur bangunan 50 tahun dan kemungkinan terlampaui 10%. Untuk kebutuhan itu, dilakukan studi analisis site-spesific response spectra pada daerah Meukek yang ditujukan untuk mempelajari kehandalan selubung respons spektrum percepatan desain untuk kelas tanah lunak zona wilayah gempa 5 dalam SNI 03-1726-2002 terhadap kejadian gempa besar yang terjadi di wilayah Aceh dan Nias beberapa waktu lalu. Karena belum adanya data riwayat waktu percepatan gempa terekam di batuan dasar yang representatif untuk wilayah Meukek, maka dilakukan perhitungan hazard kegempaan secara deterministik, serta pembuatan data riwayat waktu sintetik berdasarkan metoda stokastik dan teknik penskalaan gelombang terhadap suatu skenario gempa rencana menggunakan program SMSIM. Perambatan gelombang gempa dari batuan dasar ke permukaan tanah dianalisis berdasarkan teori perambatan gelombang geser satu dimensi dengan menggunakan program NERA dengan input stratifikasi tanah dan parameter kecepatan gelombang geser dari korelasi empiris terhadap data hasil pemboran dan uji N-SPT di lokasi kajian. Hasil  akhir adalah riwayat waktu percepatan sintetik pada lapisan batuan dasar, serta respons spektrum percepatan desain di permukaan tanah lokasi kajian berdasarkan skenario gempa yang direncanakan.Abstract. Indonesia has been well known as one of the most seismically active countries in the world. Therefore, the building design in Indonesia should consider these seismic activities. Seismic hazard analysis for any site may develops based on SNI 03-1726-2002, that implements spectral hazard for 10 % probability of exceedance in a building life time period of 50 years. In this study, a site specific response spectra was conducted on Meukek site to evaluate the performance of the response spectra based on criteria on SNI 03-1726-2002 comparing the response spectra conducted by the big earthquake event off the west coast of northern Sumatra that acted recently. There is no available strong motion data for Meukek site that is representative at this moment, therefore the Deterministic Seismic Hazard Analysis is performed, and the synthetic time histories are then simulated based on a stochastic method using SMSIM program. The analysis of shear wave propagation is performed using NERA which is based on one dimensional wave propagation theorem. Dynamic soil properties are obtained from the correlation with N-SPT value from soil investigation report covering Meukek site. The final result of this research are the synthetic time histories on the bedrock, and the design response spectrum on the site ground surface based on design earthquake scenario

Deagregasi Hazard Kegempaan Provinsi Sumatera Barat

Abstrak. Suatu studi analisis hazard kegempaan dilakukan berdasarkan kriteria desain yang disyaratkan dalam SNI 03-1726-2002, yaitu untuk umur bangunan 50 tahun dan nilai probabilitas terlampaui 10%. Deagregasi hazard dibutuhkan dalam analisis hazard kegempaan untuk menetapkan kendali jarak dan magnitude gempa dalam periode ulang tertentu. Informasi jarak dan magnitude ini merupakan bagian informasi pemilihan kriteria riwayat waktu dengan karakteristik yang mendekati kondisi yang diinginkan. Analisis tersebut dilakukan berdasarkan teori probabilitas total dengan menggunakan pemodelan sumber gempa 2-D. Hasil akhir yang diperoleh adalah peta deagregasi hazard untuk wilayah provinsi Sumatera Barat dengan periode ulang 500 tahun.Abstract. Seismic hazard analysis for any site is performed based on SNI 03-1726-2002 implementing spectral hazard for 10% probability of exceedance in design time period of 50 year. Hazard deaggregation is required in seismic hazard analysis in order to determine the controlling magnitudes and distances for particular return periods of earthquakes. The values of these magnitude and distance give the information about a criteria of certain engineering decisions on predicting acceleration time history. The analysis was performed using the total probability theorm with 2D seismic source model. The final result of this study are deaggregation hazard maps of province West Sumatera for return period of 500 years

Peta Respons Spektrum Provinsi Sumatera Barat untuk Perencanaan Bangunan Gedung Tahan Gempa

Abstrak. Gempa aceh pada bulan Desember 2004 silam telah membuktikan zona sumber gempa subduksi Sumatera mampu menghasilkan magnitude Mw9,0 yang hampir setara dengan kejadian gempa pada zona subduksi di sekitar kepulauan Mentawai pada tahun 1883. Berdasarkan pertimbangan itu, dilakukan studi analisis hazard kegempaan pada wilayah Provinsi Sumatera Barat berdasarkan kriteria desain yang disyaratkan dalam SNI-1726-2002, yaitu untuk umur bangunan 50 tahun dan nilai kemungkinan terlampaui 10%. Analisa tersebut dilakukan berdasarkan teori probabilitas total dengan memanfaatkan perangkat lunak EQRISK yang dimodifikasi dan menggunakan pemodelan sumber gempa 2-D berdasarkan kajian seismotektonik dan identifikasi regional fault. Respons spektra desain di permukaan tanah diperkirakan berdasarkan faktor amplifikasi yang mengacu pada NEHRP 1997 berdasarkan spektra percepatan di batuan dasar untuk periode 0,2 detik dan 1,0 detik. Hasil akhir yang diperoleh adalah peta spektral percepatan pada lapisan batuan dasar di wilayah Provinsi Sumatera Barat dan respons spekra desain permukaan tanah dengan periode ulang 500 tahun.Abstract. The big earthquake event acted in Desember, 2004, shows that the subduction zone of the Sumatran trench is able to produce the magnitude 9,0 which is almost equal with the magnitude of the big earthquake event on Mentawai island in 1883. Therefore, a seismic hazard analysis was conducted on area of province West Sumatera to evaluate the significant code which develops based on SNI-1726-2002, that implements spectral hazard for 10 % probability of exceedance in building life time period of 50 years. The analyses were carried out using 2-D earthquake source model and the seismic hazard analysis software named EQRISK that is based on the total probability theorm. The design response spectrum on site ground surface are approximated by the amplification factor of NEHRP 1997 codes on spectral periods of 0,2 second and 1,0 second. The final result of this study are the spectral acceleration maps on the bedrock of province West Sumatera, and the design response spectrum on site ground surface for return period of 500 years

Pembuatan Peta Spektral Percepatan Gempa Dengan Metode Probabilitas

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komputer dan bahasa pemograman visual basic

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Rekayasa Gempa Teknik Sipil

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Seismic hazard assessment of Bengkulu City using probabilistic method

This paper presents the seismic hazard assessment which involved spectral hazard for a 10% probability of exceedance in 50 years for the bedrock of Bengkulu City. The analysis was performed using the total probability theorem with a 2D seismic source model. The final results are the peak ground acceleration and the spectral acceleration on the bedrock for 475-year return periods

Mekanika Tanah

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